Etiology of breast cancer. I. Genetic aspects.

The subject of breast cancer is reviewed with particular emphasis on the genetic aspect of its etiology. A number of studies using various approaches gave the same results: the familial form occurs earlier and there is a higher risk in female members of the breast-cancer families. An association between breast cancer and cancer of certain other sites among women is reported. Cytogenetic studies of "cancer families" revealed increased frequency of aneuploidy in some members. However, the role of chromosome abnormalities in carcinogenesis is still not clear.