Breast and thyroid cancer and malignant melanoma promoted by alcohol-induced pituitary secretion of prolactin, T.S.H. and M.S.H.

In interview data from the U.S.A.'s Third National Cancer Survey, alcohol ingestion was associated with a higher occurrence of cancers of the breast, thyroid, and amlignant melanoma. Data from other studies support the first two associations. A unifying hypothesis to explain these seemingly diverse associations suggests that alcohol stimulates anterior pituitary secretion of prolactin, thyroid-stimulating hormone (T.S.H.), and melanocyte-stimulating hormone (M.S.H.). Under the stimulations of these hormones, the three target tissues exhibit increased mitotic activity and hence an increase susceptibility to the development of a malignancy. A wide variety of findings from other studies indicate plausibility for this hypothesis. The implications could be grave. In addition to alcohol, several common drugs acting in similar manner could be cancer promoters, including: resperine, methyldopa, phenothiaznes, d-amphetamine, tricyclic antidepressants, and antihistamines. Over 20000 (25%) ofall new breast-cancer cases each year in the U.S.A. could be preventable if this hypothesis is correct.