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1
Rojo, Federico, Trinidad Caldes, Sandra Zazo, Miguel de la Hoya, Cristina Carames, Atocha Romero, Gloria Serrano, et al. "Prevalence of low-penetrance KRAS (codons 12/13 and 61) and BRAF mutations in metastatic colorectal carcinoma." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): e14147-e14147. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.e14147.
Повний текст джерелаАнотація:
e14147 Background: In patients with metastatic colorectal cancer (mCRC), activating mutations within KRAS, which result in EGFR-independent intracellular signal transduction activation, are found in approximately 35-40% of patients with mCRC have been significantly associated with lack of response to cetuximab or panitumumab therapy. Although current guidelines recommend testing for frequent KRAS codons 12/13 mutations, emerging data indicate that additional KRAS and BRAF mutations are also predictive of non-responsiveness to anti-EGFR antibodies in mCRC. This study is aimed to analyze the prevalence of low-penetrance KRAS and BRAF V600 mutations in caucasian mCRC population. Methods: A two-institution retrospective cohort of 1,238 consecutive KRAS wild type mCRC patients previously studied for 7 mutations in codons 12/13 (G12D, G12A, G12V, G12S, G12R, G12C and G13D) by the CE-IVD marked ARMS-scorpion real-time polymerase chain reaction PCR (Therascreen, Qiagen) was assayed by the diagnostic TaqMelt PCR assay cobas KRAS mutation and cobas BRAF V600 mutation tests (Roche), which are designed to detect 19 mutations in KRAS codons 12, 13 and 61 (including G12F, G13C, G13R, G13S, G13A, G13V, G13I, Q61H, Q61K, Q61R, Q61L, Q61E and Q61P) and BRAF V600 (V600E, V600K and V600D) mutations. An additional cohort of 146 KRAS mutated patients by ARMS-scorpion PCR was studied. DNA was obtained by cobas DNA preparation kit from one single 5µm formalin-fixed paraffin-embedded tissue section. Results: In all samples, sufficient DNA was obtained for KRAS and BRAF mutational studies. Among 1238 KRAS codons 12/13 wild-type patients by ARMS-scorpion PCR,166 (13.4%) showed KRAS mutations, 117 (9.5%) in codons 12/13, and 49 (4%) in codon 61. BRAF V600 mutations were detected in 9% cases. In ARMS-scorpion PCR KRAS mutated patients, mutations were confirmed by cobas in all cases. Conclusions: The cobas mutation tests are robust and reproducible assays that, 1) detects a higher incidence (13.4%) of mutations in codons 12, 13, and 61 of the KRAS gene in wild-type mCRC population, 2) a relevant rate of BRAF mutations is present in the same population, and 3) requires a very small amount of tissue.
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Rabara, Dana, Timothy H. Tran, Srisathiyanarayanan Dharmaiah, Robert M. Stephens, Frank McCormick, Dhirendra K. Simanshu, and Matthew Holderfield. "KRAS G13D sensitivity to neurofibromin-mediated GTP hydrolysis." Proceedings of the National Academy of Sciences 116, no. 44 (October 14, 2019): 22122–31. http://dx.doi.org/10.1073/pnas.1908353116.
Повний текст джерелаАнотація:
KRAS mutations occur in ∼35% of colorectal cancers and promote tumor growth by constitutively activating the mitogen-activated protein kinase (MAPK) pathway. KRAS mutations at codons 12, 13, or 61 are thought to prevent GAP protein-stimulated GTP hydrolysis and render KRAS-mutated colorectal cancers unresponsive to epidermal growth factor receptor (EGFR) inhibitors. We report here that KRAS G13-mutated cancer cells are frequently comutated with NF1 GAP but NF1 is rarely mutated in cancers with KRAS codon 12 or 61 mutations. Neurofibromin protein (encoded by the NF1 gene) hydrolyzes GTP directly in complex with KRAS G13D, and KRAS G13D-mutated cells can respond to EGFR inhibitors in a neurofibromin-dependent manner. Structures of the wild type and G13D mutant of KRAS in complex with neurofibromin (RasGAP domain) provide the structural basis for neurofibromin-mediated GTP hydrolysis. These results reveal that KRAS G13D is responsive to neurofibromin-stimulated hydrolysis and suggest that a subset of KRAS G13-mutated colorectal cancers that are neurofibromin-competent may respond to EGFR therapies.
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Lee, Hyo Joo, Bonhan Koo, Yoon Ok Jang, Huifang Liu, Thuy Nguyen Thi Dao, Seok-Byung Lim, and Yong Shin. "Hot-Spot-Specific Probe (HSSP) for Rapid and Accurate Detection of KRAS Mutations in Colorectal Cancer." Biosensors 12, no. 8 (August 4, 2022): 597. http://dx.doi.org/10.3390/bios12080597.
Повний текст джерелаАнотація:
Detection of oncogene mutations has significance for early diagnosis, customized treatment, treatment progression, and drug resistance monitoring. Here, we introduce a rapid, sensitive, and specific mutation detection assay based on the hot-spot-specific probe (HSSP), with improved clinical utility compared to conventional technologies. We designed HSSP to recognize KRAS mutations in the DNA of colorectal cancer tissues (HSSP-G12D (GGT→GAT) and HSSP-G13D (GGC→GAC)) by integration with real-time PCR. During the PCR analysis, HSSP attaches to the target mutation sequence for interference with the amplification. Then, we determine the mutation detection efficiency by calculating the difference in the cycle threshold (Ct) values between HSSP-G12D and HSSP-G13D. The limit of detection to detect KRAS mutations (G12D and G13D) was 5–10% of the mutant allele in wild-type populations. This is superior to the conventional methods (≥30% mutant allele). In addition, this technology takes a short time (less than 1.5 h), and the cost of one sample is as low as USD 2. We verified clinical utility using 69 tissue samples from colorectal cancer patients. The clinical sensitivity and specificity of the HSSP assay were higher (84% for G12D and 92% for G13D) compared to the direct sequencing assay (80%). Therefore, HSSP, in combination with real-time PCR, provides a rapid, highly sensitive, specific, and low-cost assay for detecting cancer-related mutations. Compared to the gold standard methods such as NGS, this technique shows the possibility of the field application of rapid mutation detection and may be useful in a variety of applications, such as customized treatment and cancer monitoring.
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Lopez Ruitti, Paula, Ruben Salanova, Julieta Nafissi, Guillermo Rabossi, Guillermo Bramuglia, and Yanina Powazniak. "Mutational status of KRAS and BRAF of an Argentinian population of colorectal tumors." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): e14109-e14109. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.e14109.
Повний текст джерелаАнотація:
e14109 Background: Activating mutation of the KRAS oncogene is an established predictive biomarker for resistance to anti–epidermal growth factor receptor (anti-EGFR) therapies in advanced colorectal cancer (CRC). BRAF, another component of the EGFR-MAPK signal transduction pathway, is also subject to a common activating mutation in CRC. The aim of this report is to present the mutational status of KRAS, BRAF of an Argentinian population of CR tumors. Methods: Tumor blocks were obtained from 85 consenting patients of various public and private hospitals. We analyzed the presence of KRAS point mutations in codons 12 and 13, and the BRAF-V600E from formalin paraffin fixed sections with Polymerase Chain Reaction (PCR) amplification-sequencing. Results: From a total of 85 patients, 46% F and 54% M, with a median age of 64 years (range, 28-85), 72% (61) where found to be wild type, while the other 28% (24) showed the KRAS mutation in the following amino acids: G12V 30% (7), G12D 17% (4), G12C 17% (4), G12S 9% (2), G12A 4% (1), G13D 25% (6). We analyzed in 45 patients the mutational status of BRAF-V600E, 29 patients presented BRAF and KRAS wild type, 12 had a KRAS mutation while the BRAF was wild type, and 4 patients reveled a mutation of BRAF in the presence of a KRAS wild type. Conclusions: The type of mutation observed in this study corresponds to the findings of previous studies, where the most common KRAS mutation detected was G12V in codon 12 followed by G13D in codon 13. A preliminary report based in 146 patients from Argentine (Perazzo F, et al. 2009) revealed marked differences in KRAS mutation rates compared to our findings, showing the following percentage of mutations: G12V 62% vs. 30% , G12D 26% vs. 17% and G13R 1.7% vs. 0%, G13D 0% vs. 25%, respectively. BRAF mutational status was according to international and national reports.
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Yuan, Ye, Yingting Liu, Ye Wu, Junling Zhang, Chunti Shen, Feng Zhang, Changping Wu, and Wenwei Hu. "Clinical characteristics and prognostic value of the KRAS mutation in Chinese colorectal cancer patients." International Journal of Biological Markers 36, no. 2 (May 27, 2021): 33–39. http://dx.doi.org/10.1177/17246008211017152.
Повний текст джерелаАнотація:
Background: The KRAS mutations are high-frequency somatic mutations found in colorectal cancer patients from Western and Asian countries however, with the exception of exon 2 of KRAS, other prevalence and prognostic values have not been adequately assessed in Asian patients. The aim of this study was to determine the mutation frequencies of whole exon mutations of KRAS in Chinese colorectal cancer patients and to investigate their impact on prognosis. Methods: A total of 7189 tumor tissue samples (iCohort) were subjected to next-generation sequencing for detection of KRAS mutations. All pathologic or likely pathologic mutations of KRAS were considered. In addition, clinical features and prognostic dates were collected from 145 patients at The Third Affiliated Hospital of Soochow University, China (sCohort) and used droplet digital™ polymerase chain reaction to detect KRAS mutations. Results: In the iCohort, 2706 patients (37.6%) were confirmed harboring KRAS mutations. The most frequent of these mutations were G12D (32.19%), G12V (17.96%), and G13D (17.59%). In the sCohort, 51 colorectal cancer patients (35.17%) had KRAS mutations, among which KRAS G12D (64.71%), G13D (29.41%), and G14D (3.92%) were high-frequency. The KRAS mutations were associated with shorter median overall survival than wild-type tumors (69 vs. 55 months; HR 1.80; 95% Cl 1.22, 2.64; P=0.0003). In the Cox multivariate analysis, age (HR 1.562; 95% Cl 1.10, 2.22; P=0.013), tumor differentiation (HR 0.417; 95% Cl 0.19, 0.90; P=0.026), and KRAS mutation (HR 1.897; 95% Cl 0.19, 0.90; P=0.001) remained independent predictors of shorter overall survival. Among the common KRAS mutations, G12D was significantly associated with shorter overall survival (HR 2.17; 95% Cl 1.31, 3.58; P < 0.0001) compared with KRAS wild-type patients. Conclusions: Our findings indicate that KRAS genes are frequently mutated, and over 30% harbored the KRAS G12D mutation subtype. We found that the KRAS G12D mutation is associated with inferior survival and is a biomarker of poor prognosis in Chinese patients. Our data emphasize the importance of molecular features in colorectal cancer patients, which could potentially be improved by G12D-specific related inhibitors.
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Attoye, Bukola, Matthew Baker, Chantevy Pou, Fiona Thomson, and Damion K. Corrigan. "Electrochemical DNA Detection Methods to Measure Circulating Tumour DNA for Enhanced Diagnosis and Monitoring of Cancer." Proceedings 60, no. 1 (November 2, 2020): 15. http://dx.doi.org/10.3390/iecb2020-07067.
Повний текст джерелаАнотація:
Liquid biopsies are becoming increasingly important as a potential replacement for existing biopsy procedures which can be invasive, painful and compromised by tumour heterogeneity. This paper reports a simple electrochemical approach tailored towards point-of-care cancer detection and treatment monitoring from biofluids using a label-free detection strategy. The mutations under test were the KRAS G12D and G13D mutations, which are both important in the development and progression of many human cancers and which have a presence that correlates with poor outcomes. These common circulating tumour markers were investigated in clinical samples and amplified by standard and specialist PCR methodologies for subsequent electrochemical detection. Following pre-treatment of the sensor to present a clean surface, DNA probes developed specifically for detection of the KRAS G12D and G13D mutations were immobilized onto low-cost carbon electrodes using diazonium chemistry and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide coupling. Following the functionalisation of the sensor, it was possible to sensitively and specifically detect a mutant KRAS G13D PCR product against a background of wild-type KRAS DNA from the representative cancer sample. Our findings give rise to the basis of a simple and very low-cost system for measuring ctDNA biomarkers in patient samples. The current time to result of the system was 3.5 h with considerable scope for optimisation, and it already compares favourably to the UK National Health Service biopsy service where patients can wait weeks for their result. This paper reports the technical developments we made in the production of consistent carbon surfaces for functionalisation, assay performance data for KRAS G13D and detection of PCR amplicons under ambient conditions.
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Salem, Mohamed E., Scott Kopetz, Josep Tabernero, Frank A. Sinicrope, Myriam Chalabi, Jeanne Tie, Kunal C. Kadakia, et al. "Comprehensive characterization of KRAS mutations and inter-relation with primary tumor location in colorectal cancers." Journal of Clinical Oncology 41, no. 4_suppl (February 1, 2023): 231. http://dx.doi.org/10.1200/jco.2023.41.4_suppl.231.
Повний текст джерелаАнотація:
231 Background: The recent development of KRAS G12C inhibitors underscores the potential to target KRAS mutations. Right-sided and left-sided colon tumors (RT and LT) exhibit different molecular features. We characterize the prevalence of KRAS-variants, interrelation with primary tumor location, and association with immune biomarkers in CRC. Methods: We retrospectively reviewed CRC tumors of all stages (with known sidedness) that underwent NGS with the Tempus xT assay (DNA-seq of 648 genes at 500x coverage, full transcriptome RNA-seq). Bivariate analyses were performed to compare KRAS alterations, immune biomarkers, and co-mutations by tumor location. P-values comparing individual co-mutations between groups were adjusted for false discovery (FDR). Results: A total of 3,391 CRC were analyzed (RT: n = 442 [13%], transverse: n = 116 [3%], LT; n = 2,833 [84%]) of which 1486 (44%) tumors harbored KRAS mutations. Overall, KRAS mutations were more frequent in RT compared to transverse tumors and LT (52% vs 41% vs 43%, p<0.001, respectively). The most frequent KRAS mutation variants observed were G12D (29 %), G12V (22%), G13D (16%), and G12C (5.7%). There was no significant difference in the prevalence of KRAS variant types between LT and RT (p=0.5). Significant differences in genomic co-mutations with various KRAS variants were observed in the following genes: TP53, FBXW7, and NF1 (FDR- P<0.05). RT and transverse tumors were more likely have MSI-H and TMB-H (>10 mut/mb) status than LT (MSI-H: 18% vs 22% vs 2.2% and TMB-H (20% vs 22% vs 3%, P<0.001), respectively. CRC tumors harboring G13D variants were more likely to be associated with and MSI-H and TMB-H status (and 7.7% and 8.5%) compared to G12D (2.8 % and 3.9 %), G12V (1.8 % and 2.1%), and G12C (0% and 2.4%); P = 0.003 and 0.001. Conclusions: The most frequent KRAS mutation variants observed in CRC tumors were G12D, G12V, G13D, and G12C. There was no significant difference in the prevalence of KRAS variant types between tumors of the left vs right colon. CRC tumors that harbored G13D variants were significantly more likely to be associated with MSI-H and TMB-H status. [Table: see text]
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Tahir, Raiha, Santosh Renuse, Savita Udainiya, Anil K. Madugundu, Jevon A. Cutler, Raja Sekhar Nirujogi, Chan Hyun Na, Yaoyu Xu, Xinyan Wu, and Akhilesh Pandey. "Mutation-Specific and Common Phosphotyrosine Signatures of KRAS G12D and G13D Alleles." Journal of Proteome Research 20, no. 1 (September 28, 2020): 670–83. http://dx.doi.org/10.1021/acs.jproteome.0c00587.
Повний текст джерела
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Musselwhite, Laura W., Sally J. Trufan, Kunal C. Kadakia, Jimmy J. Hwang, and Mohamed E. Salem. "The prevalence of common KRAS variants and associated outcomes in patients with metastatic colorectal cancer (mCRC)." Journal of Clinical Oncology 40, no. 4_suppl (February 1, 2022): 173. http://dx.doi.org/10.1200/jco.2022.40.4_suppl.173.
Повний текст джерелаАнотація:
173 Background: KRAS is the most common driver oncogene in mCRC. Comprehensive analysis of KRAS variants prevalence and the relationship between variants and outcomes are lacking. Herein, we aimed to examine the impact of KRAS variants on outcomes in patients (pts) with mCRC. Methods: A retrospective review of pts with mCRC with known KRAS mutation status was performed. Fisher’s exact test was used to analyze the association between KRAS variants. Cox Proportional Hazard modeling was used to study the relationship between KRAS variants and overall survival (OS). Kaplan-Meier method was used to assess OS. Results: A total of 423 pts diagnosed with mCRC from 2014-2020 with available extended KRAS status were evaluated. Median age at diagnosis was 59.8 yrs (22.3-92 range), 57% were male, 22% were Black, and 75% presented with de novo metastatic disease. A majority (56%) of tumors harbored KRAS mutations. The most frequent KRAS variants were G12D 47% (111), G12V 12% (28), G12C 13% (31), G13D 9% (21), and 20% (47) were other variants. In univariate analyses, the presence of a KRAS mutation, Black race, de novo metastatic disease, age, receipt of chemotherapy, and receipt of surgery were associated with OS. Tumor location was not associated with OS. In multivariable analyses, mutation type was a significant predictor of death and the presence of G12D was associated with an increased risk of death compared to G12V and KRAS wildtype. There was no increased risk of death in pairwise comparisons of G12D and G13D or other KRAS variants. Black race, de novo metastatic disease, and no receipt of surgery were additional independent predictors of death (Table). With a median follow-up of 25.7 months (mo.), median OS was 35.5 mo. (95% CI 10.5-50.9) with G12C, Not Reached (NR) (95% CI 21-NR) with G12V, 36.2 mo. (95%CI 14.9-58.5) with G13D, 26.2 mo. (95% CI 21.8-37) with G12D, 39.6 mo. (95% CI 22.4-47.9) for other KRAS mutations, and 59.6 mo. (95%CI 48.2-NA) for KRAS wildtype, respectively (p=0.0003). Conclusions: Our findings highlight differences in unadjusted overall survival when comparing G12D to some other KRAS variants. Codon and amino acid-specific mutations of KRAS should be considered when evaluating prognosis and further study on treatment effects and sequencing is warranted. [Table: see text]
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Tejpar, Sabine, Ilhan Celik, Michael Schlichting, Ute Sartorius, Carsten Bokemeyer, and Eric Van Cutsem. "Association of KRAS G13D Tumor Mutations With Outcome in Patients With Metastatic Colorectal Cancer Treated With First-Line Chemotherapy With or Without Cetuximab." Journal of Clinical Oncology 30, no. 29 (October 10, 2012): 3570–77. http://dx.doi.org/10.1200/jco.2012.42.2592.
Повний текст джерелаАнотація:
Purpose We investigated in the first-line setting our previous finding that patients with chemorefractory KRAS G13D–mutated metastatic colorectal cancer (mCRC) benefit from cetuximab treatment. Methods Associations between tumor KRAS mutation status (wild-type, G13D, G12V, or other mutations) and progression-free survival (PFS), survival, and response were investigated in pooled data from 1,378 evaluable patients from the CRYSTAL and OPUS studies. Multivariate analysis correcting for differences in baseline prognostic factors was performed. Results Of 533 patients (39%) with KRAS-mutant tumors, 83 (16%) had G13D, 125 (23%) had G12V, and 325 (61%) had other mutations. Significant variations in treatment effects were found for tumor response (P = .005) and PFS (P = .046) in patients with G13D-mutant tumors versus all other mutations (including G12V). Within KRAS mutation subgroups, cetuximab plus chemotherapy versus chemotherapy alone significantly improved PFS (median, 7.4 v 6.0 months; hazard ratio [HR], 0.47; P = .039) and tumor response (40.5% v 22.0%; odds ratio, 3.38; P = .042) but not survival (median, 15.4 v 14.7 months; HR, 0.89; P = .68) in patients with G13D-mutant tumors. Patients with G12V and other mutations did not benefit from this treatment combination. Patients with KRAS G13D–mutated tumors receiving chemotherapy alone experienced worse outcomes (response, 22.0% v 43.2%; odds ratio, 0.40; P = .032) than those with other mutations. Effects were similar in the separate CRYSTAL and OPUS studies. Conclusion The addition of cetuximab to first-line chemotherapy seems to benefit patients with KRAS G13D–mutant tumors. Relative treatment effects were similar to those in patients with KRAS wild-type tumors but with lower absolute values.
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Attoye, Bukola, Matthew J. Baker, Fiona Thomson, Chantevy Pou, and Damion K. Corrigan. "Optimisation of an Electrochemical DNA Sensor for Measuring KRAS G12D and G13D Point Mutations in Different Tumour Types." Biosensors 11, no. 2 (February 5, 2021): 42. http://dx.doi.org/10.3390/bios11020042.
Повний текст джерелаАнотація:
Circulating tumour DNA (ctDNA) is widely used in liquid biopsies due to having a presence in the blood that is typically in proportion to the stage of the cancer and because it may present a quick and practical method of capturing tumour heterogeneity. This paper outlines a simple electrochemical technique adapted towards point-of-care cancer detection and treatment monitoring from biofluids using a label-free detection strategy. The mutations used for analysis were the KRAS G12D and G13D mutations, which are both important in the initiation, progression and drug resistance of many human cancers, leading to a high mortality rate. A low-cost DNA sensor was developed to specifically investigate these common circulating tumour markers. Initially, we report on some developments made in carbon surface pre-treatment and the electrochemical detection scheme which ensure the most sensitive measurement technique is employed. Following pre-treatment of the sensor to ensure homogeneity, DNA probes developed specifically for detection of the KRAS G12D and G13D mutations were immobilized onto low-cost screen printed carbon electrodes using diazonium chemistry and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide coupling. Prior to electrochemical detection, the sensor was functionalised with target DNA amplified by standard and specialist PCR methodologies (6.3% increase). Assay development steps and DNA detection experiments were performed using standard voltammetry techniques. Sensitivity (as low as 0.58 ng/μL) and specificity (>300%) was achieved by detecting mutant KRAS G13D PCR amplicons against a background of wild-type KRAS DNA from the representative cancer sample and our findings give rise to the basis of a simple and very low-cost system for measuring ctDNA biomarkers in patient samples. The current time to receive results from the system was 3.5 h with appreciable scope for optimisation, thus far comparing favourably to the UK National Health Service biopsy service where patients can wait for weeks for biopsy results.
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Tejpar, S., C. Bokemeyer, I. Celik, M. Schlichting, and E. Van Cutsem. "The role of the KRAS G13D mutation in patients with metastatic colorectal cancer (mCRC) treated with first-line chemotherapy plus cetuximab." Journal of Clinical Oncology 29, no. 4_suppl (February 1, 2011): 630. http://dx.doi.org/10.1200/jco.2011.29.4_suppl.630.
Повний текст джерелаАнотація:
630 Background: The CRYSTAL and OPUS studies showed that adding cetuximab (cet) to first-line chemotherapy (CT) significantly improved clinical benefit in patients (pts) with KRAS wild-type (wt) mCRC. Pts with KRAS codon 12 or 13 mutations are excluded from cet treatment. Studies suggest that not all KRAS mutations are equivalent in their biologic effects. Occasional responses and prolonged disease stabilization have been recorded following cet treatment of tumors with mainly KRAS codon 13 mutations. We investigated the influence of the most common KRAS codon 13 mutation (G13D) on clinical outcome compared with pts with other KRAS mutations or wt tumors in the CRYSTAL and OPUS trials. Methods: KRAS mutations were detected in tumor DNA from archival material using a PCR clamping and melting curve technique. Treatment arms were compared by KRAS mutation status for progression-free (PFS) and overall survival (OS). Results: In the CRYSTAL study of 1,063 evaluable pts 63% were KRAS wt, 6% were G13D mutant (mt) and 32% had other mutations. In the OPUS study of 315 evaluable pts, 57% were KRAS wt, 7% were G13D mt, and 36% had other mutations. Compared with KRAS wt pts those with G13D mutations did not benefit from the addition of cet to CT (Table). Data of comparisons of the G13D mutation with other KRAS mutations in these studies will be presented. Conclusions: Patients with KRAS G13D mt tumors did not appear to benefit from the addition of cet to first-line CT for mCRC. This analysis confirms the current practice of KRAS mutation testing as the standard diagnostic tool for determining first-line treatment of mCRC pts. [Table: see text] [Table: see text]
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Teo, Michelle Yee Mun, Jeremy Jeack Ceen Ng, Jung Yin Fong, Jung Shan Hwang, Adelene Ai-Lian Song, Renee Lay Hong Lim, and Lionel Lian Aun In. "Development of a single-chain fragment variable fused-mutant HALT-1 recombinant immunotoxin against G12V mutated KRAS colorectal cancer cells." PeerJ 9 (April 15, 2021): e11063. http://dx.doi.org/10.7717/peerj.11063.
Повний текст джерелаАнотація:
Background KRAS oncogenes harboring codon G12 and G13 substitutions are considered gatekeeper mutations which drive oncogenesis in many cancers. To date, there are still no target-specific vaccines or drugs available against this genotype, thus reinforcing the need towards the development of targeted therapies such as immunotoxins. Methods This study aims to develop a recombinant anti-mKRAS scFv-fused mutant Hydra actinoporin-like-toxin-1 (mHALT-1) immunotoxin that is capable of recognizing and eradicating codon-12 mutated k-ras antigen abnormal cells. One G13D peptide mimotope (164-D) and one G12V peptide mimotope (68-V) were designed to elicit antigen specific IgG titres against mutated K-ras antigens in immunised Balb/c mice. The RNA was extracted from splenocytes following ELISA confirmation on post-immunized mice sera and was reverse transcribed into cDNA. The scFv combinatorial library was constructed from cDNA repertoire of variable regions of heavy chain (VH) and light chain (VL) fusions connected by a flexible glycine-serine linker, using splicing by overlap extension PCR (SOE-PCR). Anti-mKRAS G12V and G13D scFvs were cloned in pCANTAB5E phagemid and superinfected with helper phage. After few rounds of bio-panning, a specific mKRAS G12V and G13D scFv antibody against G12V and G13D control mimotope was identified and confirmed using ELISA without any cross-reactivity with other mimotopes or controls. Subsequently, the anti-mKRAS scFv was fused to mHALT-1 using SOE-PCR and cloned in pET22b vector. Expressed recombinant immunotoxins were analyzed for their effects on cell proliferation by the MTT assay and targeted specificity by cell-based ELISA on KRAS-positive and KRAS-negative cancer cells. Results The VH and VL genes from spleen RNA of mice immunized with 164-D and 68-V were amplified and randomly linked together, using SOE-PCR producing band sizes about 750 bp. Anti-mKRAS G12V and G13D scFvs were constructed in phagemid pCANTAB5E vectors with a library containing 3.4 × 106 and 2.9 × 106 individual clones, respectively. After three rounds of bio-panning, the anti-mKRAS G12V-34 scFv antibody against G12V control mimotope was identified and confirmed without any cross-reactivity with other controls using ELISA. Anti-mKRAS G12V-34 scFv fragment was fused to mHALT-1 toxin and cloned in pET22b vector with expression as inclusion bodies in E. coli BL21(DE3) (molecular weight of ~46.8 kDa). After successful solubilization and refolding, the mHALT-1-scFv immunotoxin exhibited cytotoxic effects on SW-480 colorectal cancer cells with IC50 of 25.39 μg/mL, with minimal cytotoxicity effect on NHDF cells. Discussion These results suggested that the development of such immunotoxins is potentially useful as an immunotherapeutic application against KRAS-positive malignancies.
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Iiizumi, Susumu, Junya Ohtake, Naoko Murakami, Taku Kouro, Mamoru Kawahara, Fumiko Isoda, Hiroshi Hamana, Hiroyuki Kishi, Norihiro Nakamura, and Tetsuro Sasada. "Identification of Novel HLA Class II-Restricted Neoantigens Derived from Driver Mutations." Cancers 11, no. 2 (February 24, 2019): 266. http://dx.doi.org/10.3390/cancers11020266.
Повний текст джерелаАнотація:
Neoantigens derived from tumor-specific genetic mutations might be suitable targets for cancer immunotherapy because of their high immunogenicity. In the current study, we evaluated the immunogenicity of 10 driver mutations that are frequently expressed in various cancers using peripheral blood mononuclear cells from healthy donors (n = 25). Of the 10 synthetic peptides (27-mer) derived from these mutations, the six peptides from KRAS-G12D, KRAS-G12R, KRAS-G13D, NRAS-Q61R, PIK3CA-H1047R, and C-Kit-D816V induced T cell responses, suggesting that frequent driver mutations are not always less immunogenic. In particular, immune responses to PIK3CA-H1047R, C-Kit-D816V, KRAS-G13D, and NRAS-Q61R were observed in more than 10% of the donors. All six peptides induced human leukocyte antigen (HLA) class II-restricted CD4+ T cell responses; notably, PIK3CA-H1047R contained at least two different CD4+ T cell epitopes restricted to different HLA class II alleles. In addition, PIK3CA-H1047R and C-Kit-D816V induced antigen-specific CD8+ T cells as well, indicating that they might contain both HLA class I- and class II-restricted epitopes. Since the identified neoantigens might be shared by patients with various types of cancers and are not easily lost due to immune escape, they have the potential to be promising off-the-shelf cancer immunotherapy targets in patients with the corresponding mutations.
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Shinozaki, Eiji, Yoshio Miki, Masashi Ueno, Masahiro Igarashi, Mitsukuni Suenaga, Keisho Chin, Masato Ozaka, et al. "Phenotypic differences among RAS mutational variations in colorectal cancer (CRC): Analysis of 1,001 patients in single institute." Journal of Clinical Oncology 33, no. 3_suppl (January 20, 2015): 649. http://dx.doi.org/10.1200/jco.2015.33.3_suppl.649.
Повний текст джерелаАнотація:
649 Background: RAS mutation has been reported as a predictor of benefit from anti EGFR therapies in the recent sub-analysis of some large prospective trials, PRIME, FIRE-3 and so on. On the other hand, some in vitro experiments had identified the differences of capability of GTP bounding and colony formation according to KRAS mutational variations. It remains unknown whether there are phenotypic differences clinically among RAS mutational variations as potentially negative predictive factors for anti EGFR treatments. This study aimed to reveal the prevalence and the phenotypic differences of these variations in a large cohort. Methods: Consecutive patients of 1,001 CRC from January 2012 to October 2013 were analyzed in this study. Multiplex genotyping of EGFR pathway was performed on archival samples using Luminex Assay (MABGEN and GENOSEARCH Mu-PACK, MBL) for KRAS including codons 61,146 and NRAS. We examined the correlation among mutation variations; KRAS G12D, G12V, G13D and other exon2, exon 3 and 4 and NRAS, and clinical phenotypic features. Statistical analysis was conducted by chi-square test. Results: The incidence of mutations; KRAS G12D, G12V, G13D, other exon2, exon 3 and 4, and NRAS were 16.2%, 10.0%, 6.4%, 7.0%, 4.6% and 3.5%, respectively. So called all RAS mutations were occupied in 47% in this cohort. There was no significant difference of prevalence among mutational variations according to clinical feature as follows; clinical stage, gender, age. In histopathology, moderately differentiated type of G12D was more frequent compared with other type of mutations. The respective proportion of KRAS exon 3 and 4, and NRAS mutations for left sided primary was relatively higher than those for right sided, although the frequency of other mutations were higher in right side. Conclusions: According to our analysis there were not so large phenotypic differences among these RAS mutational variations except histology and localization of primary. Futher follow up of this cohort will provide more information about treatment outcomes in near future.
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Turner, Elizabeth, Luping Chen, John G. Foulke, Zhizhan Gu, and Fang Tian. "CRISPR/Cas9 Edited RAS & MEK Mutant Cells Acquire BRAF and MEK Inhibitor Resistance with MEK1 Q56P Restoring Sensitivity to MEK/BRAF Inhibitor Combo and KRAS G13D Gaining Sensitivity to Immunotherapy." Cancers 14, no. 21 (November 5, 2022): 5449. http://dx.doi.org/10.3390/cancers14215449.
Повний текст джерелаАнотація:
BRAF V600E mutation drives uncontrolled cell growth in most melanomas. While BRAF V600E tumors are initially responsive to BRAF inhibitors, prolonged treatment results in inhibitor resistance and tumor regrowth. Clinical data have linked the NRAS Q61K, KRAS G13D and MEK1 Q56P mutations to the BRAF inhibitor resistance. However, development of novel therapeutics is hindered by the lack of relevant isogeneic cell models. We employed CRISPR/Cas9 genome engineering to introduce NRAS Q61K, KRAS G13D and MEK1 Q56P mutations into the A375 melanoma cell line with endogenously high expression of BRAF V600E. The resulting isogenic cell lines are resistant to BRAF inhibitors. The A375 MEK1 Q56P isogenic cells are additionally resistant to MEK inhibitors as single agent, but interestingly, these cells become sensitive to MEK/BRAF inhibitor combo. Our results suggest that resistance in the NRAS and MEK isogenic lines is driven by constitutive MEK/ERK signaling, while the resistance in the KRAS isogenic line is driven by EGFR overexpression. Interestingly, the KRAS G13D isogenic line displays elevated PD-L1 expression suggesting the KRAS G13D mutation could be a potential indication for immunotherapy. Overall, these three novel isogenic cell models with endogenous level RAS and MEK1 point mutations provide direct bio-functional evidence demonstrating that acquiring a drug-resistant gene drives tumor cell survival and may simultaneously introduce new indications for combo therapy or immunotherapy in the clinic.
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Guglielmini, Pamela Francesca, Maura Rossi, Federica Grosso, Sara Orecchia, Marco Galliano, Elisa Bennicelli, Silvia Zai, et al. "Double KRAS and BRAF mutations in colorectal cancer in a single oncologic department series." Journal of Clinical Oncology 31, no. 15_suppl (May 20, 2013): e14657-e14657. http://dx.doi.org/10.1200/jco.2013.31.15_suppl.e14657.
Повний текст джерелаАнотація:
e14657 Background: KRAS and BRAF mutations have prognostic and predictive value in colorectal cancer and are predominantly mutually exclusive. Only a few cases of double mutations (DM) have been reported so far but the actual incidence and presumed role in worsening prognosis is still unknown. Here we report on a series of KRAS and BRAF mutations, focusing on three cases of KRAS and BRAF DM. Methods: since May 2010, 316 consecutive colorectal cancer samples were collected by our Oncology Department; ten patients (3%) had high risk localized disease and 306 (97%) metastatic disease. Genome DNA from formalin-fixed paraffin embedded samples with tumor cells > 50% was analyzed by reverse dot blot with KRAS-BRAF StripAssay kit (Nuclear Laser Medicine). Results: KRAS point mutations were found in 141 patients (44.6%): 32% G12V, 30.5% G12D, 14.9% G13D, 6.4% G12S, 5.7% G12C, 4.9% G12A, 4.9% G12R, 0.7% G13C; V600E BRAF point mutation was found in 21 patients (6.6%). Three patients (1%) displayed DM: 2 KRAS G13D + BRAF V600E (A and B) and 1 KRAS G12V + BRAF V600E (C). Patients A and C, both aged 59, presented with metastatic disease. Patient A had a rectal primary, a single lung lesion and mediastinal nodes. He failed first line FOLFOX4 plus bevacizumab and underwent salvage surgery both on primary and metastatic disease. He relapsed in 3 months with liver and brain metastasis and died after one year from diagnosis. Patient B had huge liver lesions at presentation. She progressed after 3 courses of FOLFIRI and died after 6 months from diagnosis. Patient C was operated on for a right colon cancer, G3, pT2N2, stage IIIB with lymph vascular invasion and had adjuvant FOLFOX 4. The 6-month assessment did not show relapse. Conclusions: in our series KRAS mutation incidence was in line with literature, but G12V was far more frequent. KRAS-BRAF DM accounted for 1% of all cases and the 2 patients with metastatic disease had an aggressive course with a much lower than expected survival. To our knowledge no series of DM have been described, hindering the understanding of their biological meaning. According to our experience, metastatic double mutated patients do not respond to standard therapy and should be treated with new drugs combinations in clinical trials.
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Akiyoshi, Kohei, Yasuhide Yamada, Naoki Takahashi, Yoshitaka Honma, Satoru Iwasa, Ken Kato, Tetsuya Hamaguchi, and Yasuhiro Shimada. "The efficacy of antiepidermal growth factor receptor monoclonal antibodies for patients with KRAS G13D mutations and chemorefractory metastatic colorectal cancer." Journal of Clinical Oncology 30, no. 4_suppl (February 1, 2012): 527. http://dx.doi.org/10.1200/jco.2012.30.4_suppl.527.
Повний текст джерелаАнотація:
527 Background: The treatment benefits of epidermal growth factor receptor (EGFR) monoclonal antibodies for patients with KRAS mutations have not been demonstrated. However, some studies have suggested that all KRAS mutations are not equivalent, and that KRAS G13D mutations might have some survival benefit. Methods: We retrospectively analyzed the efficacy and toxicity of treatment with EGFR monoclonal antibody in 8 patients with KRAS G13D mutations and 5-FU/oxaliplatin/irinotecan (CPT) refractory metastatic colorectal cancer compared with 94 KRAS wild type patients at the National Cancer Center Hospital. Results: Eight patients with KRAS G13D mutations were treated with anti-EGFR monoclonal antibodies between July, 2009 and July, 2011. The median age was 66 (42-70); male/female 6/2; PS was 0/1/2, 2/5/1; treatment regimen was cetuximab/ cetuximab+CPT/ panitumumab+CPT, 2/5/1. Response rate (RR) was 12.5% and disease control rate (DCR) was 50.0% with 1 PR, 3 SD, and 4 PD. The PR case treated with cetuximab+CPT showed marked regression of tumor and long duration of treatment (9 months). The progression free survival (PFS) of 2 SD cases was 4.2 and 3.9 months. The other SD case is now on treatment. The median PFS of the 8 patients was 2.1 months (95% confidence interval [CI]: 0.0-5.2). The median overall survival (OS) has not been reached. Grade 3/4 toxicities included 1 hypomagnesemia G4 and 1 rash acneiform G3. Meanwhile, 94 KRAS wild type patients treated with anti EGFR monoclonal antibodies had an RR of 22.3% and DCR was 66.0% with 21 PR, 41 SD, 30 PD, and 2 NE. PFS was 5.6 months (95% CI: 4.9-6.3) and OS was 8.6 months (95% CI: 6.5-10.7). Conclusions: In this analysis, we identified one PR to anti-EGFR monoclonal antibody in a patient with KRAS G13D mutation and chemo-refractory metastatic colorectal cancer. However, we were unable to demonstrate equivalent efficacy in patients with KRAS G13D mutations and KRAS wild type patients. Further studies are needed to evaluate the efficacy and prognosis for this treatment.
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Segelov, Eva, Kate Wilson, Val Gebski, Paul Michael Waring, Josep Tabernero, Harpreet Wasan, Fortunato Ciardiello, et al. "ICE CREAM: Irinotecan cetuximab evaluation and the cetuximab response evaluation among patients with G13D mutation." Journal of Clinical Oncology 31, no. 15_suppl (May 20, 2013): TPS3649. http://dx.doi.org/10.1200/jco.2013.31.15_suppl.tps3649.
Повний текст джерелаАнотація:
TPS3649 Background: Patients with metastatic colorectal cancer (mCRC) whose disease has progressed despite oxaliplatin and irinotecan containing regimens may benefit from the use of EGFR-inhibiting monoclonal antibodies if the tumor contains no mutations in the KRASgene (i.e. WT). However, it is unknown whether antibodies used in this setting, such as cetuximab, are more efficacious alone or in combination with irinotecan, as suggested by the BOND study which did not select for KRASstatus. This international trial will also evaluate prospectively the activity of cetuximab in the subgroup of patients with mCRC with a specific KRASmutation in codon G13D. In selected retrospective analyses, tumors bearing this mutation appear to derive similar response from cetuximab as WT. Trials involving small molecular subsets (in this case approx. 5% of patients with mCRC, or 18% of patients with KRAS mutations) will provide framework for future collaborations. Methods: This randomised phase II study of cetuximab +/- irinotecan will recruit patients with metastatic colorectal cancer (mCRC) with either KRAS WT (n=50) or G13D mutation (n=50) over 2 years from sites in Australia (12), and three international sites (G13D mutations only): Spain (1), England (1), and Italy (1). The trial will prospectively select the KRAS WT arm for the “quadruple WT" genotype (no mutations also in BRAF, NRAS, PIK3CA exon20). Primary objective is 6 month progression free survival. Secondary objectives are response rate, overall survival, quality of life, and translational research including markers that may predict response such as amphiregulin and epiregulin determined by immunohistochemistry. Eligibility: Patients with histologically confirmed CRC with either “quadruple WT" genotype or KRAS G13D mutation; unresectable metastatic disease; measurable or evaluable disease; ECOG 0-2; life expectancy at least 12 weeks, and disease progression, or intolerance of thymidylate synthase inhibitor and irinotecan and oxaliplatin containing regimens. Status: Opened to accrual November 2012, at 31 Jan 2013 3/100 patients have been enrolled, all with G13D mutations. Clinical trial information: ACTRN12612000901808.
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Segelov, Eva, Subotheni Thavaneswaran, Paul M. Waring, Jayesh Desai, Kristy P. Robledo, Val J. Gebski, Elena Elez, et al. "Response to Cetuximab With or Without Irinotecan in Patients With Refractory Metastatic Colorectal Cancer Harboring the KRAS G13D Mutation: Australasian Gastro-Intestinal Trials Group ICECREAM Study." Journal of Clinical Oncology 34, no. 19 (July 1, 2016): 2258–64. http://dx.doi.org/10.1200/jco.2015.65.6843.
Повний текст джерелаАнотація:
Purpose RAS mutations predict lack of response to epidermal growth factor receptor monoclonal antibody therapy in patients with metastatic colorectal cancer (mCRC), but preclinical studies and retrospective clinical data suggest that patients with tumors harboring the exon 2 KRAS G13D mutation may benefit from cetuximab. We aimed to assess cetuximab monotherapy and cetuximab plus irinotecan in patients with molecularly selected (G13D mutation) chemotherapy-refractory mCRC in a randomized phase II trial of this rare molecular subtype. Patients and Methods Patients with chemotherapy-refractory KRAS G13D mutation–positive mCRC who had progressed within 6 months of irinotecan therapy were randomly assigned to cetuximab 400 mg/m2 loading dose and then 250 mg/m2 once per week with or without irinotecan 180 mg/m2 once every 2 weeks. The primary end point was 6-month progression-free survival; secondary end points were response rate, overall survival, quality of life, and toxicity. Results Fifty-one of 53 patients recruited over 2 years were eligible. The 6-month progression-free survival rate was 10% (95% CI, 2% to 26%) for cetuximab versus 23% (95% CI, 9% to 40%) for cetuximab plus irinotecan with a hazard ratio of 0.74 (95% CI, 0.42 to 1.32). Response and stable disease rates were 0% and 58% for monotherapy versus 9% and 70% for combination treatment, respectively. Overall survival and quality of life were similar; toxicities were higher with combination therapy. Conclusion In patients with G13D-mutated chemotherapy-refractory mCRC, there was no statistically significant improvement in disease control at 6 months with either cetuximab monotherapy or cetuximab plus irinotecan. No responses were seen with single-agent cetuximab. The responses observed with the combination of cetuximab and irinotecan may reflect true drug synergy or persistent irinotecan sensitivity. The ICECREAM (Irinotecan Cetuximab Evaluation and Cetuximab Response Evaluation Among Patients with a G13D Mutation) study demonstrates the need to prospectively evaluate hypotheses that were previously supported by retrospective analyses and exemplifies the value of international collaboration in trials of rare molecular subtypes.
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Jung, Jaeyun, Sehhoon Park, Jeeyun Lee, and Seung Kim. "Solid tumor patients with G12V and G13D KRAS aberrations have poor survival following ICI treatment." Journal of Clinical Oncology 40, no. 16_suppl (June 1, 2022): e14567-e14567. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.e14567.
Повний текст джерелаАнотація:
e14567 Background: KRAS gene has been well known as a dominant oncogene which activates downstream signaling for tumor growth. The new therapeutic drug targeting specific KRAS mutation (G12C) has been developed and several clinical trials are testing KRAS inhibitors in solid tumor patients. In line with this, we have surveyed the prevalence and clinical features of solid tumor patients with KRAS aberration in 1,744 oncology patients who received next generation sequencing (NGS) in a clinical practice. Methods: Between 2019 amd 2021, 1,744 oncology patients have received NGS (TruSight Oncology 500 panel; 523 genes) at Samsung Medical Center. . Matched clinical and histology outcomes including programmed cell death-ligand 1 (PD-L1) 22C3 expression (n = 798) and immunotherapy treatment outcomes (n = 409) were analyzed based on genomic alteration. Results: Among the thirty-three different cancer types, the most common cancer types were colorectal cancer (CRC) (N = 547, 31.4%), followed by gastric cancer (GC) (N = 381, 21.8%), and sarcoma (N = 155, 8.9%). Of 1,744 patients, any KRAS aberrations (CNVs, SNVs) were detected in 487 (27.9%) patients (CNV: Copy Number Variation, SNV: Small Nucleotide Variation). Of the 51 (2.9%) patients with KRAS amplification, 18 (35.3%) patients were CRC followed by GC (N = 9, 17.6%). Each 4 cases were found in Cholangiocarcinoma (CCC), sarcoma, melanoma and pancreatic cancer (8%, respectively). Copy number of KRAS were distributed from 4 to over 50, while bladder cancer had the highest median value of copy number(median: 148), followed by CCC(median: 16.2). Of 454 SNV cases, the most frequent cancer type was CRC (N = 259, 57.0%) and pancreatic cancer (N = 89, 19.6%). Except 4 cases, all SNV mutation type was missense mutation. G12D amino acid change was the most frequent(N = 182), followed by G12V(N = 100), G13D(N = 48), and G12C(N = 20). However, only the patients with G12V and G13D mutation had significantly shorter OS and PFS in ICI treatment. Conclusions: Based on our comprehensive survey of next generation sequencing focused on KRAS aberration, we identified approximately 2.9% KRAS amplification and 26.0% KRAS SNV in patients with metastatic solid tumors. It was demonstrated that G12V, G13D were important mutations which were related to the response to ICI treatment in real-world data.[Table: see text]
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Jung, Jaeyun, Sehhoon Park, Jeeyun Lee, and Seung Kim. "Solid tumor patients with G12V and G13D KRAS aberrations have poor survival following ICI treatment." Journal of Clinical Oncology 40, no. 16_suppl (June 1, 2022): e14567-e14567. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.e14567.
Повний текст джерелаАнотація:
e14567 Background: KRAS gene has been well known as a dominant oncogene which activates downstream signaling for tumor growth. The new therapeutic drug targeting specific KRAS mutation (G12C) has been developed and several clinical trials are testing KRAS inhibitors in solid tumor patients. In line with this, we have surveyed the prevalence and clinical features of solid tumor patients with KRAS aberration in 1,744 oncology patients who received next generation sequencing (NGS) in a clinical practice. Methods: Between 2019 amd 2021, 1,744 oncology patients have received NGS (TruSight Oncology 500 panel; 523 genes) at Samsung Medical Center. . Matched clinical and histology outcomes including programmed cell death-ligand 1 (PD-L1) 22C3 expression (n = 798) and immunotherapy treatment outcomes (n = 409) were analyzed based on genomic alteration. Results: Among the thirty-three different cancer types, the most common cancer types were colorectal cancer (CRC) (N = 547, 31.4%), followed by gastric cancer (GC) (N = 381, 21.8%), and sarcoma (N = 155, 8.9%). Of 1,744 patients, any KRAS aberrations (CNVs, SNVs) were detected in 487 (27.9%) patients (CNV: Copy Number Variation, SNV: Small Nucleotide Variation). Of the 51 (2.9%) patients with KRAS amplification, 18 (35.3%) patients were CRC followed by GC (N = 9, 17.6%). Each 4 cases were found in Cholangiocarcinoma (CCC), sarcoma, melanoma and pancreatic cancer (8%, respectively). Copy number of KRAS were distributed from 4 to over 50, while bladder cancer had the highest median value of copy number(median: 148), followed by CCC(median: 16.2). Of 454 SNV cases, the most frequent cancer type was CRC (N = 259, 57.0%) and pancreatic cancer (N = 89, 19.6%). Except 4 cases, all SNV mutation type was missense mutation. G12D amino acid change was the most frequent(N = 182), followed by G12V(N = 100), G13D(N = 48), and G12C(N = 20). However, only the patients with G12V and G13D mutation had significantly shorter OS and PFS in ICI treatment. Conclusions: Based on our comprehensive survey of next generation sequencing focused on KRAS aberration, we identified approximately 2.9% KRAS amplification and 26.0% KRAS SNV in patients with metastatic solid tumors. It was demonstrated that G12V, G13D were important mutations which were related to the response to ICI treatment in real-world data.[Table: see text]
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Salih, Gaza Farag, and Shad Sudad. "ARMS-PCR based diagnosis of APCB and KRAS genes in colorectal cancer patients in Iraqi Sulaimania province." Journal of Solid Tumors 7, no. 1 (December 30, 2016): 27. http://dx.doi.org/10.5430/jst.v7n1p27.
Повний текст джерелаАнотація:
Amplification Refractory Mutation System (ARMS) assay is achieved for 30 blood samples of colorectal cancer (CRC) patients including 17 male and 13 female in order to determine the mutations in APCB gene and a proto-oncogene KRAS. ARMS-PCR analysis shows that all 30 samples are negative for I1307K variant (APCB) and seven common mutations in codons 12 and 13 (APCB). In addition two CRC patient samples are randomly chosen and purified for sequencing at Genome Center/KOYA University, then the sequence of the samples were BLAST on NCBI Website. The sequence alignment showed that both samples were wild for I1307K (APCB) and (G12S, G12C, G12A, G12D, G12V, G13D) (KRAS). We believe that these variants might absent in CRC patients of Iraqi Sulaimania province.
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Acoba, Jared David, Christopher A. Lum, and Lambert T. Leong. "Analysis of KRAS and BRAF mutant colorectal cancers in a multiracial population." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): 1599. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.1599.
Повний текст джерелаАнотація:
1599 Background: We previously demonstrated racial disparities in colorectal cancer (CRC) survival despite adjustments for tumor and socioeconomic factors. Molecular differences in breast and lung tumors contribute to racial survival inequality, yet in CRC, molecular tumor characteristics have not been studied extensively in a racially diverse cohort. We performed a comprehensive evaluation of KRAS and BRAF mutations in a multiracial population to determine the prevalence in CRC and the degree to which these molecular traits impact survival. Methods: A retrospective cohort study of patients diagnosed with CRC between 2008 and 2011 from hospital tumor registries was performed. The prevalence of KRAS and BRAF mutations was determined for the study population and individual racial groups. Multivariable Cox proportional hazards regression models for survival were built for KRAS and BRAF mutation status while adjusting for age at diagnosis, race, and stage of disease. Results: Of 706 patients diagnosed with CRC, KRAS mutational analysis was performed on 148 subjects. 14% of subjects were white (W), 64% Asian (A), and 21% Native Hawaiian/Pacific Islander (NH). KRAS mutation was identified in 48 subjects (32%). The prevalence of mutant tumors among racial groups was W 33%, A 36%, and NH 30%. Analysis for KRAS G13D mutations revealed a prevalence of W 11%, A 9%, and NH 7%. When compared to published datasets of predominantly white patients, our multiracial cohort had a significantly higher rate of KRAS G13D mutant tumors, p=0.039. Of 74 subjects tested for the BRAF mutation, two mutant tumors were detected (3%). The prevalence of the BRAF mutation by race was 10% W, 3% A, and 0% NH (p=0.18). BRAF and KRAS G13D mutations were adverse prognostic factors in a multivariate analysis, although the odds ratios failed to meet statistical significance. Conclusions: The prevalence of BRAF and KRAS mutations in this multiracial cohort is similar to what has been previously reported. However the rates of KRAS G13D and BRAF mutant tumors in our cohort are higher than prior reports. Furthermore, KRAS G13D which has been postulated to be a favorable prognostic factor for CRC, may adversely impact survival of minority patients.
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Maier, Attenberger, Tiwari, Lettau, Rebholz, Fehrenbacher, Schaller, Gani, and Toulany. "Dual Targeting of Y-Box Binding Protein-1 and Akt Inhibits Proliferation and Enhances the Chemosensitivity of Colorectal Cancer Cells." Cancers 11, no. 4 (April 19, 2019): 562. http://dx.doi.org/10.3390/cancers11040562.
Повний текст джерелаАнотація:
KRAS-mutated colorectal cancers (CRCs) are resistant to cetuximab treatment. The multifunctional Y-box binding protein 1 (YB-1) is overexpressed in CRC and is associated with chemoresistance. In this study, the effects of oncogenic mutated KRAS(G12V) and KRAS(G13D) on YB-1 phosphorylation were investigated in CRC cells. The effects of the inhibition of p90 ribosomal S6 kinase (RSK) on YB-1 phosphorylation, cell proliferation and survival were tested with and without treatment with 5-fluorouracil using pharmacological inhibitors and siRNA. YB-1 phosphorylation status and subcellular distribution in CRC patient tissues were determined by immunofluorescence staining and confocal microscopy. Endogenous expression of mutated KRAS(G13D) and conditional expression of KRAS(G12V) significantly stimulated YB-1 phosphorylation via RSK and were associated with cetuximab resistance. Inhibition of YB-1 by targeting RSK stimulated the Akt signaling pathway, and this stimulation occurred independently of KRAS mutational status. Akt activation interfered with the antiproliferative effect of the RSK inhibitor. Consequently, dual targeting of RSK and Akt efficiently inhibited cell proliferation in KRAS(G13D)-mutated HCT116 and KRAS wild-type SW48 cells. Treatment with 5-fluorouracil (5-FU) significantly enhanced YB-1 phosphorylation in KRAS(G13D)-mutated HCT116 cells but not in KRAS wild-type SW48 cells. Dual targeting of Akt and RSK sensitized HCT116 cells to 5-FU by stimulating 5-FU-induced apoptosis and inhibiting repair of 5-FU-induced DNA damage. YB-1 was highly phosphorylated in CRC patient tumor tissues and was mainly localized in the nucleus. Together, dual targeting of RSK and Akt may be an alternative molecular targeting approach to cetuximab for treating CRC in which YB-1 is highly phosphorylated.
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Malapelle, Umberto, Roberta Sgariglia, Alfonso De Stefano, Claudio Bellevicine, Elena Vigliar, Dario de Biase, Romina Sepe, et al. "KRAS Mutant Allele-Specific Imbalance (MASI) assessment in routine samples of patients with metastatic colorectal cancer." Journal of Clinical Pathology 68, no. 4 (January 21, 2015): 265–69. http://dx.doi.org/10.1136/jclinpath-2014-202761.
Повний текст джерелаАнотація:
AimsPatients with colorectal cancer harbouring KRAS mutations do not respond to antiepidermal growth factor receptor (anti-EGFR) therapy. Community screening for KRAS mutation selects patients for treatment. When a KRAS mutation is identified by direct sequencing, mutant and wild type alleles are seen on the sequencing electropherograms. KRAS mutant allele-specific imbalance (MASI) occurs when the mutant allele peak is higher than the wild type one. The aims of this study were to verify the rate and tissue distribution of KRAS MASI as well as its clinical relevance.MethodsA total of 437 sequencing electropherograms showing KRAS exon 2 mutation was reviewed and in 30 cases next generation sequencing (NGS) was also carried out. Five primary tumours were extensively laser capture microdissected to investigated KRAS MASI tissue spatial distribution. KRAS MASI influence on the overall survival was evaluated in 58 patients. In vitro response to anti-EGFR therapy in relation to different G13D KRAS MASI status was also evaluated.ResultsOn the overall, KRAS MASI occurred in 58/436 cases (12.8%), being more frequently associated with G13D mutation (p=0.05) and having a heterogeneous tissue distribution. KRAS MASI detection by Sanger Sequencing and NGS showed 94% (28/30) concordance. The longer overall survival of KRAS MASI negative patients did not reach statistical significance (p=0.08). In cell line model G13D KRAS MASI conferred resistance to cetuximab treatment.ConclusionsKRAS MASI is a significant event in colorectal cancer, specifically associated with G13D mutation, and featuring a heterogeneous spatial distribution, that may have a role to predict the response to EGFR inhibitors. The foreseen implementation of NGS in community KRAS testing may help to define KRAS MASI prognostic and predictive significance.
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Gvaldin, Dmitry Yu, Oleg I. Kit, Ekaterina P. Omelchuk, Dmitry O. Kaymakchi, Sergey I. Poluektov, Dmitry Sergeevich Petrov, Vladimir E. Kolesnikov, and Liubov Yu Vladimirova. "Frequency of somatic mutations in the KRAS gene in patients of the South Russia diagnosed with colorectal cancer." Journal of Clinical Oncology 37, no. 15_suppl (May 20, 2019): e15081-e15081. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.e15081.
Повний текст джерелаАнотація:
e15081 Background: Colorectal cancer (CRC) is a common pathology in the world; the annual incidence rate reaches 1 million cases, and the annual mortality rate exceeds 500,000. The target therapy of EGFR with monoclonal drugs improves the survival of patients with this pathology. However, the effectiveness of therapy depends on the presence of mutations in genes involved in the EGFR signaling cascade, in particular KRAS. The purpose of this study was to determine the frequency of somatic mutations in the KRAS gene in tumor samples of patients from the South Russia diagnosed with colorectal cancer, as well as to analyze the effect of point mutations G12A, G12C, G12D, G12R, G12S, G12V and G13D on tumor metastasis. Methods: 744 patients diagnosed with colorectal adenocarcinoma were examined for mutations in 12th and 13th codons of KRAS. Somatic mutations in the KRAS gene were detected with reagent kit Biolink (Russia) using FFPE DNA samples of tumor tissues. Statistical analysis was performed using the method of binary logistic multiple regression and χ2-test. Results: Mutations in the KRAS gene were found in 32% of patients in the pooled sample; the most common mutation was the replacement of G12D in the KRAS gene (36%). Less common detectable mutations in the KRAS gene were G13D (18%), G12V (16%), G12A (10%), G12C (8%), G12S (10%), G12R (2%). Metastatic CRC was found in 86% of carriers of the wild-type allele and in 88% of carriers of the mutant allele. The presence of a G12V substitution almost 6 times increased the risk of metastasis in patients with CRC (OR = 5.89; 95% CI: 0.8-43.45; p = 0.049). Conclusions: Mutations in the KRAS gene were found in 32% of patients with CRC in the South of Russia. A significant association of G12V replacement with a high risk of metastasis was established. Further study of somatic mutations in the KRAS gene will allow to choose the most effective therapeutic strategies in the presence of one or another of the studied mutations.
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Lu, Jia, John Hunter, Anuj Manandhar, Deepak Gurbani, and Kenneth D. Westover. "Structural dataset for the fast-exchanging KRAS G13D." Data in Brief 5 (December 2015): 572–78. http://dx.doi.org/10.1016/j.dib.2015.10.001.
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Berger, Andreas W., Daniel Schwerdel, Hanna Welz, Thomas Jens Ettrich, Peter Moeller, and Thomas Seufferlein. "The occurrence of mutant KRAS clones in the blood of RAS wild type colorectal cancer patients: Impact of response or failure under anti-EGFR therapy." Journal of Clinical Oncology 34, no. 4_suppl (February 1, 2016): 600. http://dx.doi.org/10.1200/jco.2016.34.4_suppl.600.
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600 Background: Colorectal cancer (CRC) is characterized by a high level of genetic heterogeneity. In addition, changes in the genetic profile induced by chemotherapy affect treatment results. Acquired resistance of tumors is defined as a result of clonal evolution and clonal selection under systemic chemotherapy. Repeated tumor tissue biopsies are difficult to obtain and cannot be easily used for dynamic monitoring of therapy response or failure due to marked tumor heterogeneity. Promising data for circulating cell-free tumor DNA (ctDNA) as a tool for studying tumor evolution were recently published. Methods: In this study we analyzed ctDNA from patients with metastatic CRC during treatment with anti-epidermal growth factor receptor (EGFR) antibodies (cetuximab/panitumumab). By droplet digital PCR we performed genotyping of CRC tissue and tracking of clonal evolution of the most frequent KRAS mutations (G12A, G12C, G12D, G12R, G12S, G12V, G13C, G13D, Q61R, A146T and A59T) in plasma ctDNA. Results: In initial KRAS wild type tumors several mutated KRAS clones occurred in plasma under the course of anti-EGFR-therapy indicating an increasing acquired resistance to the given therapy leading to a disease progression. Some of these mutations declined upon discontinuation of anti-EGFR therapy. Conclusions: Based on these results we hypothesize that the initial state of KRAS wild type situation seems to be restored in some cases. This opens up the possibility to reinduce anti-EGFR therapy in later therapy lines.
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Yu, Zhiping, Hongyi Su, Jianzhong Chen, and Guodong Hu. "Deciphering Conformational Changes of the GDP-Bound NRAS Induced by Mutations G13D, Q61R, and C118S through Gaussian Accelerated Molecular Dynamic Simulations." Molecules 27, no. 17 (August 30, 2022): 5596. http://dx.doi.org/10.3390/molecules27175596.
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The conformational changes in switch domains significantly affect the activity of NRAS. Gaussian-accelerated molecular dynamics (GaMD) simulations of three separate replicas were performed to decipher the effects of G13D, Q16R, and C118S on the conformational transformation of the GDP-bound NRAS. The analyses of root-mean-square fluctuations and dynamics cross-correlation maps indicated that the structural flexibility and motion modes of the switch domains involved in the binding of NRAS to effectors are highly altered by the G13D, Q61R, and C118Smutations. The free energy landscapes (FELs) suggested that mutations induce more energetic states in NRAS than the GDP-bound WT NRAS and lead to high disorder in the switch domains. The FELs also indicated that the different numbers of sodium ions entering the GDP binding regions compensate for the changes in electrostatic environments caused by mutations, especially for G13D. The GDP–residue interactions revealed that the disorder in the switch domains was attributable to the unstable hydrogen bonds between GDP and two residues, V29 and D30. This work is expected to provide information on the energetic basis and dynamics of conformational changes in switch domains that can aid in deeply understanding the target roles of NRAS in anticancer treatment.
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Adderley, Helen M., Mihaela Aldea, Jaqueline Aredo, Mathew Carter, Matthew Church, Pantelis Nicola, Jamie Weaver, et al. "Abstract 2975: RAS precision medicine transatlantic partnership: Exploration of RAS and NF1 co-mutations in NSCLC." Cancer Research 82, no. 12_Supplement (June 15, 2022): 2975. http://dx.doi.org/10.1158/1538-7445.am2022-2975.
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Abstract Background: RAS is the most commonly mutated oncogene in cancer, with KRAS mutated in ~30% of non-small cell lung cancer (NSCLC). RAS is a small GTPase cycling between GTP-bound ‘ON’ state and GDP-bound ‘OFF’ state. KRAS oncoproteins cycle between these states via hydrolysis and nucleotide exchange with the aid of GAPs, including NF1, and GEFs. Given the ’inactive state’ inhibition of recently developed KRAS G12C inhibitors on the GDP-bound state, this has highlighted the continued reliance of KRAS-mutants upon cycling, and the potential for mutants to retain dependence upon upstream influences, including NF1, for pathogenicity. Methods: 474 patients with advanced RAS- and/or NF1-mutant NSCLC were retrospectively identified from four tertiary cancer centers between 2008 -2021. DNA from archival FFPE samples, serum or combination underwent targeted NGS panels to identify mutations. Molecular, clinical, pathological and treatment outcome data were collected. Online resources including cBioPortal and Project Achilles were used to assess the functional role of any findings. Results: KRAS mutations were identified in 416/474 patients and NF1-mutations in 63/474 patients, eight of whom harbored two NF1-mutations. 24/63 (38%) of NF1-mutant cancers had a concomitant KRAS-mutation. We identified that KRAS G13D was more prevalent in NF1 mutant cancers vs. NF1 wildtype (NF1 MT: 6/24, 25%; vs. NF1 WT: 4/281, 1.4%; p<0.0001). KRAS G12C was identified in 11/24 (45.8%) of the double mutants vs. 109/282 (38.7%) of the NF1 WT patients (p=0.52). Those with G13D/NF1 co-mutation had a predicted pathogenic NF1-mutation in 5/6 (83%) of cases. Functional analysis of NF1 KO in G13D mutant lung cancer cell lines identified that NF1 was more essential in G13D mutant cell lines, with median Chronos score -0.26 G13D vs. -0.04 G12C (p=0.02). mRNA expression data identified a range of mRNA expression Z-scores relative to all samples for NF1-mutant cancers, ranging from lowest expression at -4.54 to +1.63, median -0.51. A higher mRNA expression was identified for NF1 missense mutations of unknown significance compared to truncating mutations with likely pathogenic, loss of function. Conclusions: These results highlight the co-mutational landscape of KRAS G13D with NF1 in NSCLC, suggesting functional importance conferred by NF1 loss, and highlight NF1 mutations as an additional pathogenic even when combined with KRAS mutation. The genomic landscape of KRAS and NF1 mutant NSCLC will be explored further through Whole Genome Sequencing data from the 100,000 Genomes Project (Genomics England). Citation Format: Helen M. Adderley, Mihaela Aldea, Jaqueline Aredo, Mathew Carter, Matthew Church, Pantelis Nicola, Jamie Weaver, Aisha Ghaus, Damien Vasseur, Matthew Krebs, Nicola Steele, Fiona Blackhall, Heather Wakelee, Benjamin Besse, Colin Lindsay. RAS precision medicine transatlantic partnership: Exploration of RAS and NF1 co-mutations in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2975.
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Nakamura, Masato, Toru Aoyama, Keiichiro Ishibashi, Akihito Tsuji, Yasutaka Takinishi, Yoshiaki Shindo, Junichi Sakamoto, Koji Oba, and Hideyuki Mishima. "Randomized phase II study of cetuximab versus irinotecan and cetuximab in patients with chemo-refractory KRAS codon G13D metastatic colorectal cancer (G13D-study)." Cancer Chemotherapy and Pharmacology 79, no. 1 (November 22, 2016): 29–36. http://dx.doi.org/10.1007/s00280-016-3203-7.
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De Falco, Elena, Luca Pacini, Daniela Bastianelli, Gian Paolo Spinelli, Chiara Spoto, Enzo Veltri, and Antonella Calogero. "Concomitant Mutations G12D and G13D on the Exon 2 of the KRAS Gene: Two Cases of Women with Colon Adenocarcinoma." Diagnostics 11, no. 4 (April 6, 2021): 659. http://dx.doi.org/10.3390/diagnostics11040659.
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Colorectal cancer (CRC) is rapidly increasing representing the second most frequent cause of cancer-related deaths. From a clinical-molecular standpoint the therapeutically management of CRC focuses on main alterations found in the RAS family protein, where single mutations of KRAS are considered both the hallmark and the target of this tumor. Double and concomitant alterations of KRAS are still far to be interpreted as molecular characteristics which could potentially address different and more personalized treatments for patients. Here, we firstly describe the case of two patients at different stages (pT2N0M0 and pT4cN1cM1) but similarly showing a double concurrent mutations G12D and G13D in the exon 2 of the KRAS gene, normally mutually exclusive. We also evaluated genetic testing of dihydropyrimidine dehydrogenase (DPYD) and microsatellite instability (MSI) by real-time PCR and additional molecular mutations by next generation sequencing (NGS) which resulted coherently to the progression of the disease. Accordingly, we reinterpreted and discuss the clinical history of both cases treated as single mutations of KRAS but similarly progressing towards a metastatic asset. We concluded that double mutations of KRAS cannot be interpreted as univocal genomic alterations and that they could severely impact the clinical outcome in CRC, requiring a tighter monitoring of patients throughout the time.
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Okada, Satoshi, Keisuke Hata, Kazushige Kawai, Yoko Yamamoto, Toshiaki Tanaka, Takeshi Nishikawa, Kazuhito Sasaki, et al. "Association between KRAS G13D mutations and anastomotic recurrence in colorectal cancer." Medicine 98, no. 12 (March 2019): e14781. http://dx.doi.org/10.1097/md.0000000000014781.
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Peeters, Marc, Jean-Yves Douillard, Eric Van Cutsem, Salvatore Siena, Kathy Zhang, Richard Thomas Williams, and Jeffrey S. Wiezorek. "Mutant (MT) KRAS codon 12 and 13 alleles in patients (pts) with metastatic colorectal cancer (mCRC): Assessment as prognostic and predictive biomarkers of response to panitumumab (pmab)." Journal of Clinical Oncology 30, no. 4_suppl (February 1, 2012): 383. http://dx.doi.org/10.1200/jco.2012.30.4_suppl.383.
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383 Background: Pmab is a fully human monoclonal antibody against the epidermal growth factor receptor (EGFR). Significant improvement in progression-free survival (PFS) was demonstrated in pts with wild-type (WT) KRAS mCRC treated with pmab+FOLFOX4 (1st-line; study 20050203), pmab+FOLFIRI (2nd-line; study 20050181), and pmab monotherapy (study 20020408). In mCRC, mutations in KRAS codons 12 and 13 are established biomarkers for lack of clinical benefit to anti-EGFR therapies. We retrospectively examined individual MT KRAS codon 12 and 13 alleles as prognostic and predictive biomarkers of response in three phase 3 studies. Methods: Pts were randomized to receive FOLFOX4, FOLFIRI, or best supportive care +/- pmab 6.0 mg/kg Q2W in studies 20050203, 20050181, and 20020408, respectively. The MT KRAS codon 12 and 13 alleles (G12A, G12C, G12D, G12R, G12S, G12V, G13D) were detected using the Therascreen K-RAS Mutation Kit (Qiagen). Results: MT KRAS codon 12 and 13 alleles were detected in 40% (440/1096), 45% (486/1083), and 43% (184/427) of pts in studies 20050203, 20050181, and 20020408, respectively. MT KRAS allele distribution was conserved across studies and balanced between treatment arms. Baseline demographic and clinical features were comparable between all MT KRAS allele subgroups. Across all studies, no single MT KRAS allele was consistently prognostic for PFS or overall survival (OS) in the control arm-treated pts. Similarly, no single MT KRAS allele was a consistent positive or negative predictive factor for PFS or OS in pmab-treated pts. Only in the pmab+FOLFOX4 arm of study 20050203 were G13D (unfavorably) and G12V (favorably) significantly associated with OS. Response rates were similar between MT KRAS allele groups in the 1st- and 2nd-line mCRC treatment setting. Finally, in analyses of pts pooled from all 3 trials, only the G12A KRAS allele emerged as a significant negative predictive factor for OS. Conclusions: The lack of consistent results across three lines of therapy indicates pts with MT KRAS codon 12 or 13 alleles are unlikely to respond to pmab therapy. Currently, only pts with WT KRAS mCRC should be treated with pmab.
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Peeters, Marc, Jean-Yves Douillard, Eric Van Cutsem, Salvatore Siena, Kathy Zhang, Richard Thomas Williams, and Jeffrey S. Wiezorek. "Mutant (MT) KRAS codon 12 and 13 alleles in patients (pts) with metastatic colorectal cancer (mCRC): Assessment as prognostic and predictive biomarkers of response to panitumumab (pmab)." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): 3581. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.3581.
Повний текст джерелаАнотація:
3581 Background: Pmab is a fully human monoclonal antibody against the epidermal growth factor receptor (EGFR). Significant improvement in progression-free survival (PFS) was demonstrated in pts with wild-type (WT) KRAS mCRC treated with pmab+FOLFOX4 (1st-line; study 20050203), pmab+FOLFIRI (2nd-line; study 20050181), and pmab monotherapy (study 20020408). In mCRC, mutations in KRAS codons 12 and 13 are established biomarkers for lack of clinical benefit to anti-EGFR therapies. We retrospectively examined individual MT KRAS codon 12 and 13 alleles as prognostic and predictive biomarkers of response in three phase 3 studies. Methods: Pts were randomized to receive FOLFOX4, FOLFIRI, or best supportive care +/- pmab 6.0 mg/kg Q2W in trials 20050203, 20050181, and 20020408, respectively. The MT KRAS codon 12 and 13 alleles (G12A, G12C, G12D, G12R, G12S, G12V, G13D) were detected using the Therascreen K-RAS Mutation Kit (Qiagen). Results: MT KRAS codon 12 and 13 alleles were detected in 40% (440/1096), 45% (486/1083), and 43% (184/427) of pts in trials 20050203, 20050181, and 20020408, respectively. MT KRAS allele distribution was conserved across studies and balanced between treatment arms. Baseline demographic and clinical features were comparable between all MT KRAS allele subgroups. There was no consistent evidence that any individual MT KRAS allele, compared to the remaining MT KRAS alleles or the entire MT KRAS group, differentially impacted PFS or overall survival (OS) in control arm-treated or pmab-treated pts. Only in the pmab+FOLFOX4 arm of study 20050203 were G13D (unfavorably) and G12V (favorably) significantly associated with OS. Response rates were similar between MT KRAS allele groups in the 1st- and 2nd-line mCRC treatment setting. Finally, in analyses of pts pooled from all 3 trials, only the G12A KRAS allele emerged as a significant negative predictive factor for OS. Conclusions: The lack of consistent results across three lines of therapy indicates pts whose tumors harbor MT KRAS codon 12 or 13 alleles are unlikely to respond to pmab therapy. Currently, only pts with WT KRAS mCRC should be treated with EGFR antibodies.
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Ishibashi, Keiichiro, Masato Nakamura, Akihito Tsuji, Yasutaka Takinishi, Yoshiaki Shindo, Toru Aoyama, Junichi Sakamoto, Koji Oba, and Hideyuki Mishima. "Randomized phase II study of cetuximab vs. irinotecan and cetuximab in patients with chemo-refractory KRAS codon G13D metastatic colorectal cancer (G13D-study): Compared with ICECREAM study." Annals of Oncology 28 (June 2017): iii109—iii110. http://dx.doi.org/10.1093/annonc/mdx261.311.
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Ntai, Ioanna, Luca Fornelli, Caroline J. DeHart, Josiah E. Hutton, Peter F. Doubleday, Richard D. LeDuc, Alexandra J. van Nispen, et al. "Precise characterization of KRAS4b proteoforms in human colorectal cells and tumors reveals mutation/modification cross-talk." Proceedings of the National Academy of Sciences 115, no. 16 (April 2, 2018): 4140–45. http://dx.doi.org/10.1073/pnas.1716122115.
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Mutations of the KRAS gene are found in human cancers with high frequency and result in the constitutive activation of its protein products. This leads to aberrant regulation of downstream pathways, promoting cell survival, proliferation, and tumorigenesis that drive cancer progression and negatively affect treatment outcomes. Here, we describe a workflow that can detect and quantify mutation-specific consequences of KRAS biochemistry, namely linked changes in posttranslational modifications (PTMs). We combined immunoaffinity enrichment with detection by top-down mass spectrometry to discover and quantify proteoforms with or without the Gly13Asp mutation (G13D) specifically in the KRAS4b isoform. The workflow was applied first to isogenic KRAS colorectal cancer (CRC) cell lines and then to patient CRC tumors with matching KRAS genotypes. In two cellular models, a direct link between the knockout of the mutant G13D allele and the complete nitrosylation of cysteine 118 of the remaining WT KRAS4b was observed. Analysis of tumor samples quantified the percentage of mutant KRAS4b actually present in cancer tissue and identified major differences in the levels of C-terminal carboxymethylation, a modification critical for membrane association. These data from CRC cells and human tumors suggest mechanisms of posttranslational regulation that are highly context-dependent and which lead to preferential production of specific KRAS4b proteoforms.
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Al-Turkmani, M. Rabie, Kelley N. Godwin, Jason D. Peterson, and Gregory J. Tsongalis. "Rapid Somatic Mutation Testing in Colorectal Cancer by Use of a Fully Automated System and Single-Use Cartridge: A Comparison with Next-Generation Sequencing." Journal of Applied Laboratory Medicine 3, no. 2 (September 1, 2018): 178–84. http://dx.doi.org/10.1373/jalm.2018.026278.
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AbstractBackgroundMolecular tests have been increasingly used in the management of various cancers as more targeted therapies are becoming available as treatment options. The Idylla™ system is a fully integrated, cartridge-based platform that provides automated sample processing (deparaffinization, tissue digestion, and DNA extraction) and real-time PCR-based mutation detection with all reagents included in a single-use cartridge. This retrospective study aimed at evaluating both the Idylla KRAS and NRAS-BRAF-EGFR492 Mutation Assay cartridges (research use only) against next-generation sequencing (NGS) by using colorectal cancer (CRC) tissue samples.MethodsForty-four archived formalin-fixed paraffin-embedded (FFPE) CRC tissue samples previously analyzed by targeted NGS were tested on the Idylla system. Among these samples, 17 had a mutation in KRAS proto-oncogene, GTPase (KRAS), 5 in NRAS proto-oncogene, GTPase (NRAS), and 12 in B-Raf proto-oncogene, serine/threonine kinase (BRAF) as determined using the Ion AmpliSeq 50-gene Cancer Hotspot Panel v2. The remaining 10 samples were wild-type for KRAS, NRAS, and BRAF. Two 10-μm FFPE tissue sections were used for each Idylla run, 1 for the KRAS cartridge, and 1 for the NRAS-BRAF-EGFR492 cartridge. All cases met the Idylla minimum tumor content requirement for KRAS, NRAS, and BRAF (≥10%). Assay reproducibility was evaluated by testing commercial controls derived from human cell lines, which had an allelic frequency of 50% and were run in triplicate.ResultsThe Idylla system successfully detected all mutations previously identified by NGS in KRAS (G12C, G12D, G12V, G13D, Q61K, Q61R, A146T), NRAS (G12V, G13R, Q61H), and BRAF (V600E). Compared with NGS, Idylla had a sensitivity of 100%. Analysis of the mutated commercial controls demonstrated agreement with the expected result for all samples and 100% reproducibility. The Idylla system produced results quickly with a turnaround time of approximately 2 h.ConclusionThe Idylla system offers reliable and sensitive testing of clinically actionable mutations in KRAS, NRAS, and BRAF directly from FFPE tissue sections.
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Almeida, Thiago Lins, Jessica Ribeiro Gomes, Marcel Cerqueira Cesar Machado, Antonio C. Buzaid, and Fernando C. Maluf. "RAS mutations and their correlation with survival of patients with advanced pancreatic adenocarcinoma." Journal of Clinical Oncology 33, no. 3_suppl (January 20, 2015): 325. http://dx.doi.org/10.1200/jco.2015.33.3_suppl.325.
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325 Background: The prognosis of pancreatic adenocarcinoma (PA) remains poor despite FOLFIRINOX and nab-paclitaxel-gemcitabine based chemotherapy. The epidermal growth factor receptor (EGFR) has a major role in pancreatic cancer carcinogenesis.The RAS status showed to be a predictive factor for response to anti-EGFR therapy in colon cancer. We aim to analyze the K-RAS and N-RAS status in PA and its prognostic impact. Methods: Retrospective analysis included 24 patients with metastatic (67%) or locally advanced (29%) PA at diagnosis (AEMOC, Brazil). K-RAS and N-RAS profile were performed by polymerase chain reaction and bidirectional sequencing (codons 12, 13, 61, 117, 146). The results were then analyzed in regards to overall survival (OS) and progression-free survival (PFS) in PA. Results: The sample showed: median age of 63 years (28-86), 62.5% male, 45.8% smoker, head site (67%), ductal (68%), and mild differentiation features (45%). The first-line therapy was FOLFIRINOX (62.5%) and gemcitabine (33.3%). The median PFS and OS were 6.5 and 13 months (mo), respectively. Nineteen patients (79.1%) presented mutation in K-RAS: four c.35G>A (G12D), four c.34G>C (G12R), four c.35G>T (G12V), three c.35G>C (G12A), one c.437C>T (A146V), and one c.34G>T (G12C). Mutation in N-RAS (c.38G>A (G13D) was detected in only one patient (4%). The only independent factor for survival was K-RAS status: the c.35G>A (G12D) polymorphism yielded worse PFS and OS when compared to non-c.35G>A (G12D) mutation: 3 vs 7 mo [HR 0.25, 95% CI, (0.04–1.63)] for PFS (p<0,0043) and 3.5 vs13 mo [HR 0.17, 95% CI, 0.01-1.58)] for OS (p<0,0001), respectively. Conclusions: K-RAS was the only prognostic factor for PFS and OS, with the polymorphism c.35G>A (G12D) being related to a worse prognostic. Further studies are necessary to better evaluate whether K-RAS and N-RAS status is prognostic and/or predictive factor.
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Wen, Zhengqi, Hushan Zhang, Ruize Zhou, Xihong Liu, and Wenliang Li. "Abstract 5403: Genetic, immunologic and prognostic heterogeneity in CRC patients with KRAS mutations." Cancer Research 82, no. 12_Supplement (June 15, 2022): 5403. http://dx.doi.org/10.1158/1538-7445.am2022-5403.
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Abstract Genetic, immunologic and prognostic heterogeneity in CRC patients with KRAS mutations Background Currently, most patients with mCRC are treated with a combination of a cytotoxic and a biologic agent. Several factors should be put into account which influencing the treatment strategy for patients with mCRC. including tumor resectability, prior systemic therapy; tumor location (left or right), and molecular characteristics such as mutation in gene Kirsten rat sarcoma viral oncogene homolog (KRAS). It has been demonstrated to be a tightly associated with poor response to anti-EGFR treatment, and even poor response to immune checkpoint inhibitors for patients with colorectal cancer. Therefore, KRAS mutational status testing has been highlighted in recent years. Methods This study queried the data from Formalin-Fixed Paraffin-Embedded (FFPE) tissues of 2,294 CRC patients which underwent a targeted next-generation sequencing assay performed by 3DMed Clinical Laboratory Inc., a College of American Pathologists (CAP) certified and Clinical Laboratory Improvement Amendments (CLIA) certified laboratory of 3D Medicines Inc. between January, 2017 and June, 2020 in China, to obtain a comprehensive molecular profile of KRAS mutations. Co-occurring genomic alterations, tumor mutational burden (TMB), microsatellite instability (MSI) status and PD-L1 expression (Dako 22C3 or VentanaSP263, TPS score) were analyzed. High TMB was defined as TMB ≥10 muts/Mb. Postoperative follow-up data for 27 patients were collected and analyzed. Results KRAS mutation account for 48.7% Chinese CRC patients. In addition, proportions of KRAS mutation in different exons were counted. KRAS mutation in CRC mainly occurred in exon2 (84.0%), exon3 (6.1%), exon4 (7.4%), and exon5 (0.7%). KRAS mutation in exon2, the main mutations were G12D (35.4%), G12V (20.8%), G13D (21.9%), G12C (5.9%) ad G12S (5.8%). while in exon3 and exon4, the main mutations were Q61H (50.7%) and A146T (73.2%), respectively. The proportion of MSI-H in CRC patients with and without KRAS mutation were very close. While it seemed that there were more MSI-H patients in KRAS exon3 and exon4 mutation. In addition, PD-L1 expression was detected in 1220 tumor samples by means of IHC. Among these available tumor samples, level of PD-L1expression were similar among patients without KRAS mutation, KRAS mutation in different exons, but it reveled that there were very small part of patient with strong positive PD-L1 level (TPS≥50). In addition, different prognosis were found among different mutations of KRAS exon2, in detail, worse PFS was showed in CRC patients with KRAS mutation in exon2 G12D than G12V and G13D. Conclusions CRC patients with KRAS mutations in different exons and different site have different genetic and prognostic characteristics, these patients should be managed differently in clinical practice. Citation Format: Zhengqi Wen, Hushan Zhang, Ruize Zhou, Xihong Liu, Wenliang Li. Genetic, immunologic and prognostic heterogeneity in CRC patients with KRAS mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5403.
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Kobayashi, T., T. Masaki, H. Matsuoka, and M. Sugiyama. "Anti-EGFR Antibody Treatment in KRAS G13D Mutation-Type Colorectal Cancers: Case Reports." Annals of Oncology 23 (October 2012): xi159. http://dx.doi.org/10.1016/s0923-7534(20)32500-x.
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El zaitouni, Sara, Abdelilah Laraqui, Meriem Ghaouti, Asmae Benzekri, Fouad Kettani, Hicham El Annaz, Rachid Abi, et al. "Mutation status of full RAS and BRAF in 169 Moroccan patients with colorectal cancer." Journal of Clinical Oncology 41, no. 4_suppl (February 1, 2023): 216. http://dx.doi.org/10.1200/jco.2023.41.4_suppl.216.
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216 Background: Morocco has the highest cancer mortality rate in MENA Countries. Colorectal cancer (CRC) is classified as the first digestive cancer and remains a burden in Morocco. According to the data on GLOBOCAN 2020, there were 4324 new CRC patients and 2374 deaths, accounting for 7.3% and 2.8% of all cancers, respectively. Our study aimed to investigate the frequency of the full RAS ( KRAS, NRAS) and BRAF genes in CRC patients from Morocco and their possible associations with clinico-pathological features. Methods: Archived FFPE of 169 CRC patients were screened for KRAS, NRAS and BRAF mutations by Idylla technology. Results: Full RAS mutations were identified in 46.1% (42% in KRAS, 4.1% in NRAS). In KRAS gene, exon 2 mutations accounted for 84.5% (69% in codon 12, 15.5 % in codon 13). Within codon 12, KRAS G12D and G12C were more frequently detected (29.5% and 16.9%, respectively). Detection of KRAS mutations, and particularly G12D and G12C subtypes, are of large significance for CRC patients, have possible therapeutic implications. Within codon 13, the most frequently observed mutation was G13D (15.5 %). Outside exon 2, the mutation rate was 35.1% (8.4% in exon 3 and 26.7% in exon 4). Concurrent KRAS mutations were identified in 8 cases, which suggests that multiple mutations can occur in the same or different codons. In NRAS gene, the mutation rates of exon 2 and 3 were 71.4% and 57.1% respectively. G13V and Q61K were the most common mutations, accounting for 28.6 % of each. Concurrent KRAS mutations were identified in 2 cases. Of the 169 samples, mutations in the BRAF gene at V600E were detected in 3.5%. Combined mutational analysis of KRAS, NRAS and BRAF was able to identify 49.6% of patients with CRC as likely non-responders to anti-EGFR therapy. There was an association between KRAS mutations and age, which were higher in the age group>50 years old (p=0.022). Tumors in the left colon (36.61%) are more likely to harbor mutations in KRAS than the rectum (19.7%) in both sexes. The adenocarcinoma well-differentiated was the most frequent for patients with KRAS mutations (54.9%). No significant clinicopathologic correlations with NRAS and BRAF mutations were identified. Conclusions: Beside established anti-CRC treatment, better understanding of the causality of CRC can be established by combining epidemiology and genetic/epigenetic on CRC etiology in Morocco. This approach may be able to significantly reduce the burden of disease in the country. Moreover, the Moroccan government should develop policy on CRC prevention and public health programs which may serve as a feasible setting to increase public awareness on lifestyle risk factors.
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Ni Nyoman, Ayu Dewi, Ni Made Pramita Widya Suksmarini, Anak Agung Ngurah Satya Pranata, Andreliano Yosua Rompis, and I. Wayan Juli Sumadi. "The prevalence of KRAS and BRAF mutation in colorectal cancer patients in Bali." Indonesian Journal of Biotechnology 27, no. 1 (March 29, 2022): 29. http://dx.doi.org/10.22146/ijbiotech.67506.
Повний текст джерелаАнотація:
Mutations in the KRAS (Kirsten rat sarcoma viral oncogene homolog gene) and BRAF (v‐Raf murine sarcoma viral oncogene homolog B1) gene play a significant role in primary resistance to colorectal cancer therapy. Around 85‐90% of KRAS mutations in colorectal cancer occur in exon 2 (codon 12 and 13), whereas approximately 96% of BRAF mutations occur in exon 15 codon 600 (V600E). This study aimed to determine the prevalence and mutation characteristics of the KRAS and BRAF genes in colorectal cancer patients in Bali. The DNA was isolated from 44 formalin‐fixed paraffin‐embedded colorectal cancer samples which were stored in the Department of Pathology, Sanglah General Hospital in 2017. Detection of mutation was carried out by polymerase chain reaction (PCR) and direct sequencing. Out of 44 samples, only 27 were successfully amplified and sequenced. Our findings showed six samples (22.2%) with mutated KRAS at codons 12 and 13 (including two samples with G12D, one sample with G12V, and three samples with G13D). Interestingly, we found three samples (11.1%) of BRAF mutation, including two samples with V600E mutation and one with V600L mutation. Taken together, our results showed that KRAS and BRAF mutations were identified and occurred exclusively. Further studies are essential to identify the correlation of these mutations with colorectal cancer prognosis and response to chemotherapy
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Ning, Wenjuan, Zhang Yang, Gregor J. Kocher, Patrick Dorn, and Ren-Wang Peng. "A Breakthrough Brought about by Targeting KRASG12C: Nonconformity Is Punished." Cancers 14, no. 2 (January 13, 2022): 390. http://dx.doi.org/10.3390/cancers14020390.
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KRAS is the most frequently mutated oncogene in lung carcinomas, accounting for 25% of total incidence, with half of them being KRASG12C mutations. In past decades, KRAS enjoyed the notorious reputation of being untargetable—that is, until the advent of G12C inhibitors, which put an end to this legend by covalently targeting the G12C (glycine to cysteine) substitution in the switch-II pocket of the protein, inhibiting the affinity of the mutant KRAS with GTP and subsequently the downstream signaling pathways, such as Raf/MEK/ERK. KRASG12C-selective inhibitors, e.g., the FDA-approved AMG510 and MRTX849, have demonstrated potent clinical efficacy and selectivity in patients with KRASG12C-driven cancers only, which spares other driver KRAS mutations (e.g., G12D/V/S, G13D, and Q61H) and has ushered in an unprecedented breakthrough in the field in recent decades. However, accumulating evidence from preclinical and clinical studies has shown that G12C-targeted therapeutics as single agents are inevitably thwarted by drug resistance, a persistent problem associated with targeted therapies. A promising strategy to optimize G12C inhibitor therapy is combination treatments with other therapeutic agents, the identification of which is empowered by the insightful appreciation of compensatory signaling pathways or evasive mechanisms, such as those that attenuate immune responses. Here, we review recent advances in targeting KRASG12C and discuss the challenges of KRASG12C inhibitor therapy, as well as future directions.
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Lu, Lianghao, Julie Niemela, Thomas Fleisher, Joie Davis, Iusta Caminha, Mark Natter, Laurel Beer, et al. "Somatic KRAS mutations associated with a human non-malignant syndrome of autoimmunity and abnormal leukocyte homeostasis (47.4)." Journal of Immunology 186, no. 1_Supplement (April 1, 2011): 47.4. http://dx.doi.org/10.4049/jimmunol.186.supp.47.4.
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Abstract Autoimmune lymphoproliferative syndrome (ALPS) is a non-malignant disease characterized by early-onset chronic lymphadenopathy, splenomegaly, multilineage cytopenias, polyclonal hypergammaglobulinemia, expansion of circulating TCRαβ+B220+CD4-CD8- T (αβ+-DNT) lymphocytes, and an increased risk of B-cell lymphoma. Most ALPS patients have germline or somatic TNFRSF6 (FAS) mutations, and a small minority of patients have germline mutations in FAS ligand and caspase 10. We recently reported that an ALPS-like phenotype can be caused by a somatic NRAS mutation (G13D) resulting in the defective lymphocyte apoptosis. Here we demonstrate that somatic mutations in the related KRAS gene can also be associated with a non-malignant syndrome of autoimmunity and breakdown of leukocyte homeostasis. The activating KRAS mutation (G13C) impaired cytokine-withdrawal induced T cell apoptosis through the suppression of the pro-apoptotic protein BIM and facilitated proliferation through p27kip1 downregulation. These defects could be corrected by MEK1 or PI3K inhibition in vitro. We suggest the use of the term RAS-associated autoimmune leukoproliferative disease (RALD) to differentiate this disorder from ALPS. In the hematopoietic system, somatic KRAS and NRAS mutations are commonly observed in aggressive tumors such as multiple myeloma or juvenile myelomonocytic leukemia (JMML). From our reports, we think patients with somatic KRAS and NRAS mutations can follow a more benign clinical course.
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Yu, Helena Alexandra, Camelia S. Sima, Ronglai Shen, Samantha Lindsay Kass, Mark G. Kris, Marc Ladanyi, and Gregory J. Riely. "Comparison of the characteristics and clinical course of 677 patients with metastatic lung cancers with mutations in KRAS codons 12 and 13." Journal of Clinical Oncology 31, no. 15_suppl (May 20, 2013): 8025. http://dx.doi.org/10.1200/jco.2013.31.15_suppl.8025.
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8025 Background: Patients (pts) with KRAS mutant lung cancers have a shorter survival compared to pts with KRAS/EGFR wild type tumors (Johnson et al, Cancer 2012). Whether outcomes for patients with KRAS mutant metastatic lung cancers differ by smoking status or specific amino acid substitution is unknown. In order to understand the impact of KRAS mutation subtype in the metastatic setting, we analyzed a large cohort of patients with KRAS mutant metastatic lung cancer. Methods: We identified all pts with KRAS mutant metastatic or recurrent lung cancers from Feb 2005 to Aug 2011. KRAS mutation type, clinical characteristics, and outcomes from diagnosis were obtained from the medical record. A multivariate cox proportion hazard model was used to identify factors associated with overall survival. Results: KRAS mutations were identified in 677 pts (53 at codon 13, 624 at codon 12). Median age: 66 (range 31-89), women: 62%, never smokers: 7%. Pts with transition mutations (n=157) were more likely to be never-smokers (p<0.0001). There was no difference in outcome for pts with KRAS transition versus transversion mutations (p=1) or when comparing current/former smokers to never smokers (p=0.33). There was no difference in overall survival (OS) when comparing specific amino acid substitutions (G12C=366, G12V=141, G12D=114, G12A=68, G13C=27, G13D=23, G12S=19, G12F=11)(p=0.20). Pts with KRAS codon 13 mutant tumors had inferior OS compared to pts with codon 12 mutant tumors, median 13 months (mo) (95% CI 13-17 mo) and 16 mo (95% CI 9-16 mo), respectively (p=0.009). There was no difference in frequency of receiving platinum-based chemotherapy or chemotherapy of any kind between pts with codon 12 and 13 mutant tumors. In a multivariate Cox model which included age, gender and smoking status, KRAS codon 13 mutation was associated with worse overall survival than KRAS codon 12 mutation (HR 1.52 95% CI 1.11-2.08 p=0.008). Conclusions: Among pts with KRAS mutant metastatic lung cancers, smoking history, and specific amino acid substitution do not affect outcome. Patients with KRAS codon 13 mutant metastatic lung cancer have shorter survival compared to pts with KRAS codon 12 mutant lung cancer.
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Liu, Li, Yuan Liu, Ademi Santiago-Walker, Hong Shi, Vivian Zhang, Ashley Hughes, Carmen P. Arenas-Elliott, Lori Roadcap, Anne-Marie Martin, and Tona M. Gilmer. "Genetic and molecular biomarker characterization of KRAS mutant non-small cell lung carcinoma (NSCLC) tumors." Journal of Clinical Oncology 31, no. 15_suppl (May 20, 2013): 11026. http://dx.doi.org/10.1200/jco.2013.31.15_suppl.11026.
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11026 Background: Preclinical studies demonstrated Brahma related gene 1 (BRG1) mutations or loss of expression, and mutations of LKB1 may be associated with lack of sensitivity for MEK inhibitor trametinib in a subset of KRAS mutant NSCLC lines. This study aimed to evaluate the frequency of KRAS, LKB1 and BRG1 mutations in NSCLC tumors; and determine whether KRAS mutations in corresponding plasma samples could be detected by evaluating circulating cell-free DNA (cfDNA). Methods: Human NSCLC FFPE tumor tissue and matched plasma samples were procured from Indivumed GmbH. KRAS mutation status of 101 NSCLC tumors and matched plasma were determined by direct sequencing of genomic DNA (gDNA) from tissue and/or BEAMing on tissue gDNA or plasma cfDNA. Genetic mutations of LKB1 and BRG1 were determined by direct sequencing. Additional mutations were determined using the Ion Torrent AmpliSeq Cancer Panel. BRG1 protein expression was evaluated by IHC. Results: By direct sequencing and BEAMing we found 27/101 (28.4%) NSCLC tissue and/or plasma samples harbored KRAS mutations: G12V (37.0%), G12C (29.6%), G12D (18.5%), G12S, G13C, G13D and Q61H (3.7% each). The KRAS mutation status concordance (mutant or wild-type) between tumor gDNA and plasma cfDNA was 79-81%. Among the KRAS mutant tumors, LKB1 and BRG1 mutations were detected in 10/26 (38%) and 1/26 (3.8%) tumors respectively by direct sequencing. By IHC, loss of BRG1 expression was detected in 1/21 KRAS mutant tumors. The mutation frequency and variants for KRAS and LKB1 in patient samples were comparable with KRAS mutant NSCLC cell lines and COSMIC database. However the frequency of BRG1 mutation and protein loss were much lower in patient tumors. In a subset of 15 KRAS mutant tumors, Ion Torrent confirmed KRAS and LKB1 mutations and provided additional mutations found in TP53, FGFR2, FGFR3, GNAS, KDR, KIT and MET. Conclusions: This study demonstrates that KRAS mutant NSCLC tissues have high frequency of LKB1 mutations along with other mutations. It also supports the feasibility of detection of KRAS mutations in cfDNA from blood of NSCLC patients using BEAMing technology, providing an alternative to invasive biopsy.
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Muthiah, Arun, Rani Chudasama, Adam J. Olszewski, Harish Saiganesh, Habibe Kurt, Jennifer Mingrino, Maria Garcia-Moliner, et al. "Clinical characteristics, co-mutations and outcomes of advanced non-small cell lung cancer (NSCLC) patients with KRAS mutations." Journal of Clinical Oncology 39, no. 15_suppl (May 20, 2021): e21174-e21174. http://dx.doi.org/10.1200/jco.2021.39.15_suppl.e21174.
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e21174 Background: Mutations (mt) in the KRAS gene are common oncogenic drivers in advanced NSCLC. The KRAS mt subtypes and certain co-mutations (co-mt) have prognostic and predictive implications. New drugs promise to uniquely target KRAS G12C, raising interest in studying the unique clinical and molecular characteristics of this subtype. Methods: We retrospectively identified 56 KRAS mt advanced NSCLC patients (pts) that underwent Next-Generation Sequencing (NGS) from 06/2015 to 12/2020. We used a commercial NGS panel that tested for > 300 genomic alterations, including substitutions, insertions, deletions and copy number alterations. For statistical analysis, we divided the patients into G12C and non-G12C groups. Results: In our cohort of 56 KRAS mt pts, median age was 67 (range: 58-74) with a predominance of females (63%) and heavy smokers (89%). KRAS G12C was the most common subtype 38%; G12V 14%, G12D 11%, G12S 11%, G13D 7% and others < 5% each. G12C, G12D and G13D groups had a higher proportion of PD-L1+ tumors (84%, 100%, and 100% respectively, p = 0.02) compared to other KRAS subtypes. Pts in G12C group were on average older (median age 71 vs 61, p = 0.02) than non-G12C. Most frequent co-mt in G12C were TP53 (33%), STK11 (29%), TET2 (19%), RB1 (14%), CDKN2A/B (14%) , MCL1 (14%) and ASXL1 (14%) ; for non-G12C, they were TP53 (54%), CDKN2A/B (37%), STK11 (34%) and RBM10 (17%). CDKN2A/B co-mt (37% vs 14%, p = 0.08) was significantly more frequent in non-G12C group and TET2 in G12C (19% vs 0%, p = 0.016). Non-G12C group more frequently had high TMB (17% vs 0%, p = 0.07) compared to G12C. No difference in survival was seen between G12C and non-G12C groups. We observed no difference in PFS (p = 0.31) or OS (p = 0.64) between smokers and no/light-smokers with KRAS mt. Co-mt with KEAP1 and SMARCA4 were significantly associated with survival in KRAS mt. Compared to KRAS+/KEAP1wt, KRAS +/ KEAP1+ pts had poor PFS (median 1.1 vs 7.5 m, p < 0.0001) and OS (1.1 vs. 27.8 m, p < 0.0001) measured from start of initial therapy. KRAS+/SMARCA4+ had worse PFS (1.0 vs 6.9 m, p < 0.0001) and OS (1.4 vs. 27.8, p = 0.0001) compared to KRAS+/SMARCA4wt. KRAS mt pts with STK11/KEAP1 that were treated with immunotherapy-based regimens had shorter PFS (1.1 vs 7.6 m, p = 0.001) and OS (1.4 vs 90.9 m, p = 0.0007) compared to those treated with chemotherapy alone. Conclusions: Our data shows that pts with KRAS co-mt with STK11/KEAP1 had worse PFS and OS with the addition of immunotherapy compared to chemotherapy alone, highlighting the potential implications of these co-mt patterns on treatment outcomes. The types of co-mts are similar between KRAS G12C and non-G12C, with the exception of CDKN2A/B (less likely) and TET2 (more likely). Larger data sets are warranted to confirm our observations and determine if these co-mts may create a predictive model for individualized therapy for KRAS mt pts, potentially independent of current predictive markers.
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Stover, D. G., A. M. Cushman-Vokoun, C. L. Vnencak-Jones, and J. Berlin. "Analysis of BRAF and KRAS mutations in colorectal cancer and rectal carcinogenesis via fluorescent allele-specific PCR." Journal of Clinical Oncology 29, no. 4_suppl (February 1, 2011): 436. http://dx.doi.org/10.1200/jco.2011.29.4_suppl.436.
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436 Background: Molecular analysis has become increasingly relevant in the evaluation of colorectal carcinomas. Mutations in Ras-MAPK pathway proteins KRAS (present in 30-40% of colorectal cancer) and BRAF (10-14% of colorectal cancer) or mismatch repair (MMR) enzymes can impact response to therapy and/or can assist in defining hereditary predisposition. High frequency microsatellite instability (MSI) in colorectal cancer is associated with improved outcomes. Targeted therapies against BRAF and other components of the Ras-MAPK signaling pathway are becoming important aspects of treatment in colorectal and other cancers. Methods: A retrospective study was performed on 111 paraffin-embedded tumor specimens submitted between 1/07 and 3/09 for MSI testing based on family history and/or histologic features. DNA samples were screened for the BRAF V600E mutation and 7 KRAS mutations in codons 12 and 13 using fluorescent allele specific PCR with capillary electrophoresis. Clinical data was collected via chart review. Results: 58 males and 53 females were studied. The incidence of KRAS and BRAF mutations among the 111 samples was 49.5% and 6.3%, respectively. KRAS G12D and G12V were the most common mutations, representing 57% of total KRAS mutations. Dually positive KRAS and MSI tumors exclusively demonstrated G12D and G13D mutations. KRAS and BRAF mutations were mutually exclusive. Rectal cancers did not show evidence of BRAF V600E mutation (p=0.04). KRAS, BRAF, and MSI status did not correlate with survival, however pre-operative and post-operative carcinoembryonic antigen (CEA) levels were significantly associated with survival both in univariate and multivariate analyses. Conclusions: We demonstrate that BRAF V600E mutation is significantly associated with colon cancer and not rectal cancer, suggesting that BRAF mutations are not relevant in rectal carcinogenesis. Correlation between specific KRAS mutation and outcome may require larger populations. No significant financial relationships to disclose.