Genetic Predisposition to Breast Cancer

Abstract

The question of an inherited genetic basis for breast cancer has been debated for at least 50 years. Although familial aggregations of the disease have been described since the nineteenth century or longer, the debate seemingly commenced with the initiation of retrospective studies in which the frequency of breast cancer in the relatives of a large series of patients was compared with the frequency in some control group. These early studies indicated two- to fourfold risks for the disease among the relatives and that the increased risks applied only to breast cancer, i.e., the genetic effect was site-specific. (See reviews by CLEMMESEN, 1965; POST, 1966.) These studies were criticized on the grounds that the study and control groups were not comparable and/or the analytical procedures were inadequate. But later studies, such as those of WOOLF (1955), ANDERSON et al. (1958), TOKUHATA (1969), and MACKLIN (1959), using improved methodologies and more critical analytical techniques, yielded similar risks and again, evidence of a site-specific effect. The magnitude of these genetic risks was little different from those of other risk determinants including single vs. married women, low vs. high parity, early vs. late menopause, late vs. an early age at delivery, or from comparisons of high vs. low socioeconomic class (MAcMAHON et al., 1973).

The original work cited in this report was supported in part by Grant GM 19513, C-1 and Contract N01-CB-44004, from” the National Institutes of Health.