Genetic factors in human breast cancer

Abstract

The apparent environmental risk factors for breast cancer in human populations have been previously reviewed in an anthropological context. Most epidemiologic studies have been concerned with breast cancer at the population level rather than at the level of high-risk families. Thus, the genetic factors in human breast cancer have not yet been clearly defined, and the genetic form(s) of breast cancer have not been clearly distinguished from breast cancer in the general population. Despite this lack of specificity, family history appears to be the single most influential risk factor for breast cancer in human populations. A subset of breast cancer cases, among populations both at low risk and high risk of developing cancer, that appear to be under genetic influence, are identified. The heritable form(s) can be characterized and distinguished from the overall pattern of breast cancer in the general population. Observations at the population level appear to be consistent with a role for genetic factors in the development of breast cancer. Recent evidence also suggests that the heritable form(s) of breast cancer are influenced by a single, autosomal dominant gene. Linkage relationships may exist between genetic markers that are close to this susceptibility gene. New methodologies determine the direction of future anthropological studies of breast cancer susceptibility and of strategies for prevention.