Breast cancer genetic factors

BRCAl as a Genetic Marker for Breast Cancer Genetic Factors in the Familial Transmission of the Breast Cancer BRCAl Gene... 

CYPI7 genetic polymorphism, breast cancer, and breast cancer risk factors. Breast Cancer Res. 5, R45-51. 

Breast Cancer. Many studies have observed low incidences of hormone-dependent cancers, particularly breast cancer, in Asian countries compared with Western countries and it is becoming increasingly accepted that dietary factors play an important role. Although breast cancer can occur in either males or females, only about 1 % of all cases occur in men, and male breast cancer is a rare disease in all parts of the world." Although there appear to be some similar risk factors for breast cancer in males and females, there is no indication in the literature that diet is either a risk or a protective factor for male breast cancer. The development of breast cancer is known to be highly dependent on the hormones associated with female reproductive functions, while established genetic factors have been... 

The etiology of breast cancer is unknown, but a number of factors that increase a woman s chances of developing the disease have been identified. These risk factors, as well as information regarding the biology of the disease, suggest that a complex interplay between hormones, genetic factors, and environmental and lifestyle influences all contribute to the etiology of this disease. 

McPherson K, Steel CM, Dixon JM (2000) ABC of breast cancer Epidemiology, risk factors and genetics. Br Med J 321 624-628... 

For many common diseases, subsets of cases exist in which genetic factors play an especially important role. These subsets tend to develop disease early in life (e.g., BRCAl and BRCA2 mutations in breast cancer), and they often tend to have a more severe expression of the disease (e.g., APC mutations in colon cancer). 

Other host factors What other host factors may modify the carcinogenic response to ionizing radiation remains unclear, but it seems plain that hormonal factors, at least, play such a role in breast cancer. Immime competence and genetic characteristics, e.g., those governing DNA repair capabilities, are also possibilities. 

Breast cancer has a multifactorial etiology involving numerous genetic, metabolic, and cultural variables. Table I presents a summary of many epidemiological studies designed to identify risk factors for breast cancer (2-8). 

A critical question concerns the possible value of dietary intervention as a preventive or therapeutic measure. There is little doubt that fat intake influences breast cancer development in rodents at levels which are found in the human diets. However, conclusive evidence is lacking about the quantitative and qualitative aspects of these processes and how fat in diets may be modified to reduce human cancer incidence. It is likely that dietary intervention may prove useful initially as a preventive or therapeutic measure in isolated groups of high risk individuals. As genetic, hormonal, and immunologic risk factors became more clearly defined, individuals at high risk and those with breast cancer may benefit from therapeutic low-fat diets whose efficacy will require assessment in well-designed clinical studies. 

The strongest risk factors for breast cancer are female gender and increasing age. Additional risk factors include endocrine factors (e.g., early menarche, nulliparity, late age at first birth, hormone replacement therapy), genetic factors (e.g., personal and family history, mutations of tumor suppresser genes [BRCAl and BRCA2]), and environmental and lifestyle factors (e.g., radiation exposure). 

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