This text investigates the hypothesis that endogenous estrogens function as primary carcinogens in the development of breast and prostate cancers. The National Cancer Institute presents a comprehensive review of hormonal mechanisms, examining how estrogen metabolites interact with cellular DNA to initiate malignant transformations. The research synthesizes epidemiological data, biochemical pathways, and clinical observations to argue that hormonal exposure is a critical factor in oncogenesis for these specific tissues.

Experts recognize this document as a technical resource for researchers and oncologists focusing on the hormonal etiology of cancer. Readers frequently note the academic density of the prose and the reliance on specialized biochemical terminology throughout the analysis.