Exogenous hormones and human cancer.

The importance of the role of endogenous hormones in carcinogenesis of the breast, endometrium, ovary and testis is well known. Exogenous hormones have become an important issue in human carcinogenesis because the number of case reports suggesting its relation to iatrogenic hormone usage is increasing due to the increased hormone consumption from various medical treatments. The risk of adenoma and carcinoma of the liver and endometrium caused by oral contraceptives has been clarified after relatively long-term experience. We have reviewed the risk from exogenous hormones, such as oral contraceptives, supplemented estrogens, tamoxifen, synthetic anabolic steroids, including danazol, clomiphene and growth hormone, and other growth factors produced by genetic engineering because of their possible role in causing human neoplasms.