Abstract
Because mammary carcinomas are derived from cells in which growth and function are subject to influence by a variety of hormonal agents, it is not surprising that endocrine factors play a part in the induction and subsequent proliferation of such neoplasms. In spite of several decades of intensive study, the precise mechanisms by which hormones influence the origin and growth of mammary tumors remain obscure. From investigations in various disciplines of biomedical research, patterns of evidence are now emerging that promise a better understanding of the phenomenon of hormone dependency in breast cancers and of the relation of hormones to . . .