Książki na temat „Incremental lifetime cancer risk”

This chapter, found in the radiation exposure from medical imaging section of the book, provides a succinct synopsis of a key study estimating the potential radiation-induced cancer risk to pediatric patients undergoing computed tomography scans. This summary outlines the study methodology and design, major results, limitations and criticisms, related studies and additional information, and clinical implications. The study demonstrated that pediatric patients are at significantly increased lifetime radiation risks from CT compared to adults, and that every effort should be made to eliminate unnecessary radiation exposure among them. In addition to outlining the most salient features of the study, a clinical vignette is included in order to provide relevant clinical context.

The general assumption behind cancer screening has been that early diagnosis and treatment is effective at reducing cancer-related mortality; this is broadly speaking true, for some cancer screening efforts, in some age groups. However, screening may in some cases do more harm than good. One source of harm is overdiagnosis and overtreatment, the diagnosis and treatment of indolent or slow-growing disease that may never lead to morbidity or mortality in the lifetime of the patient. Precaution in cancer screening is thus a double-edged sword: early diagnosis and treatment has clear benefits; but it is also true that some percentage of patients is unnecessarily treated. This chapter will examine how inductive risk and values come into play in debates about mammography screening.

Prostate cancer is the commonest male malignancy, with approximately 35 000 new cases in the UK annually, equating to a lifetime risk of 1 in 10. When diagnosed early, it has a high chance of cure with surgery, external beam radiotherapy, or brachytherapy. Even for metastatic disease, the prognosis is usually several years.

It is estimated that more than one million women are diagnosed with breast cancer every year and more than 410,000 women die from breast cancer representing 14% of female cancer deaths.Breast cancer is the most common female malignancy in the UK and USA. In the UK, 30,000 new cases and 15,000 deaths occur each year due to breast cancer. In the USA, there are 192,000 new cases and 43,300 breast cancer deaths every year. The lifetime risk of developing breast cancer for a woman is 1 in 12 in the UK and 1 in 8 in the USA....

Breast cancer is the commonest female cancer, with a lifetime risk of approximately 1 in 9. There are approximately 40 000 new cases and 11 000 deaths from the disease in England and Wales each year. Breast cancer is an adenocarcinoma which arises from the glandular tissue of the breast. Its etiology is complex, with hormonal, genetic, and modifiable lifestyle factors all involved in developing the disease. Prognosis is related to the anatomical extent of the cancer, and other factors. This chapter discusses the definition and etiology of breast cancer, as well as its typical symptoms, less common symptoms, demographics, natural history, complications, diagnosis, treatment, and prognosis.

Primary hepatocellular carcinoma (HCC) arises from hepatocytes and is one of the commonest solid-organ malignancies in the world, particularly in the Far East and in sub-Saharan Africa. Cholangiocarcinoma arises from the biliary epithelium. The incidence is rising in the West, and primary sclerosing cholangitis (PSC) is an important risk factor (15% lifetime risk). Other forms of liver cancer include metastatic cancer, which is much more common in the West than any primary liver cancer, accounting for 90% of liver cancers and for which common primary sites are the colon, the stomach, the breasts, and the lungs; hepatoblastoma, which is an uncommon malignancy in children, originating from immature liver cell precursors; haemangiosarcomas, which are also rare, are malignant tumours arising from the blood vessels in the liver and can be very rapidly growing; and gall bladder cancer, arising from the gall bladder epithelium. Gallstones and PSC are risk factors for gall bladder cancer; in particular, PSC confers a risk >160 times that of the control population. This chapter primarily focuses on HCC.

The incidence of prostate cancer (PCa) has risen dramatically in the last years. This event may be partially explained by the employment of digital rectal examination (DRE), serum prostate-specific antigen (PSA), and transrectal ultrasonography. In developed countries, PCa is the most frequent non-skin malignancy in males. It is estimated that one in six males will be diagnosed with PCa during their lifetime, the risk of death due to metastatic PCa being 1 in 30. Multiple factors contribute to the development of PCa, as well as to its progression to an androgen-independent state: dietary factors, inherited susceptibility factors, gene defects, and androgens and their receptors. The chapter will discuss the following topics: high-grade prostatic intraepithelial neoplasia (PIN); atypical small acinar proliferation; morphological criteria for the identification of PCa; reporting of PCa biopsies; prognostic factors in radical prostatectomies (RPs); and specimens.

In the UK, the four commonest cancers—lung cancer, breast cancer, colon cancer, and prostate cancer—result in around 62 000 deaths every year. Although deaths from cancer have fallen in the UK over the last 20 years, the UK still suffers from higher cancer death rates than many other countries in Western Europe. In 1999, the UK government produced a White Paper called Saving Lives: Our Healthier Nation that outlined a national target to reduce the death rate from cancer by at least 20% in people under 75 by 2010. The subsequent NHS Cancer Plan of 2000 designed a framework by which to achieve this target through effective prevention, screening, and treatment programmes as well as restructuring and developing new diagnostic and treatment facilities. But do we know enough about the biology of the development of cancer for government health policies alone to force dramatic changes in survival? The science behind the causes of cancer tells us that its origin lies in acquired or inherited genetic abnormalities. Inherited gene mutation syndromes and exposure to environmental mutagens cause cancer, largely through abnormalities in DNA repair mechanisms, leading to uncontrolled cell proliferation. Although screening those thought to be at highest risk, and regulating exposure to environmental carcinogens such as tobacco or ionizing radiation, have reduced, and will continue to reduce, cancer deaths, there are many other environmental factors that have been shown to increase the population risk of cancer. These will be outlined in this chapter. However, the available evidence is largely from retrospective and cross-sectional population-based studies and therefore limits the ability to apply this knowledge to the risk of the individual patient who may been seen in clinic. Although we may be able to put him or her into a high-, intermediate-, or low-risk category, the question ‘will I get cancer, doc?’ is one that we cannot answer with certainty. The NHS Cancer Plan of 2000, designed to reduce cancer deaths in this country and to bring UK treatment results in line with those other countries in Europe, focuses on preventing malignancy as part of its comprehensive cancer management strategy. It highlights that the rich are less likely to develop cancer, and will survive longer if they are diagnosed than those who live in poverty. This may reflect available treatment options, but is more likely to be related to the lifestyle of those with regular work, as they may be more health aware. The Cancer Plan, however, suggests that relieving poverty may be more labour intensive and less rewarding than encouraging positive risk-reducing behaviour in all members of the population. Eating well can reduce the risk of developing many cancers, particularly of the stomach and bowel. The Cancer Plan outlines the ‘Five-a-Day’ programme which was rolled out in 2002 and encouraged people to eat at least five portions of fruit and vegetables per day. Obese people are also at higher risk of cancers, in particular endometrial cancer. A good diet and regular exercise not only reduce obesity but are also independent risk-reducing factors. Alcohol misuse is thought to be a major risk factor in around 3% of all cancers, with the highest risk for cancers of the mouth and throat. As part of the Cancer Plan, the Department of Health promotes physical activity and general health programmes, as well as alcohol and smoking programmes, particularly in deprived areas. Focusing on these healthy lifestyle points can potentially reduce an individual lifetime risk of all cancers. However, our knowledge of the biology of four cancers in particular has led to the development of specific life-saving interventions. Outlined in this chapter are details regarding ongoing prevention strategies for carcinomas of the lung, the breast, the bowel, and the cervix.

Urinary bladder cancer (UBC) ranks ninth in worldwide cancer incidence. The most common histological type in Western countries is transitional cell carcinoma (TCC), while in Africa, a substantial proportion of squamous cell carcinomas (SCC) are observed related to the prevalence of infection with Schistosoma haematobium (bilharziasis). UBC has the highest per-patient lifetime cost for cancer in terms of healthcare expenditure compared to all other types of cancer. It is more frequent in men than in women and age is now widely accepted as the greatest single risk factor for developing UBC. The median age at diagnosis is 70 years. Cigarette smoking and specific occupational exposures, such as carcinogenic dyes for painters, are the main known causes of UBC.