NONESTROGENIC DRUGS AND BREAST CANCER

Abstract
The relation between breast cancer and selected nonestrogenic drugs was evaluated in the Group Health Cooperative of Puget Sound, Seattle, Washington, a prepaid health care organization with computerized information on diagnoses and outpatient drug use. No important positive associations with breast cancer were found in a follow-up study of 302 women aged 35–74 years. These women were newly diagnosed with breast cancer in 1977–1980 and were studied in relation to exposure in the six months prior to diagnosis to one or more of the following drugs: diazepam, digitalis glycosides, medroxyprogesterone acetate, methyldopa, metronidazole, phenothiazines, tricyclic antidepressants, thiazides, thyroid/levothyroxine sodium, or spironolactone. A modest association between recent reserpine use and breast cancer was present (risk ratio = 1.7, 90% confidence interval 0.9-3.3).