The Roles of Estrogen and Progesterone in Breast and Genital Cancer

Abstract

The incidence of mammary and genital cancer was investigated in a group of 304 women whose ages ranged from 40 to 70 years (average 50.8) and who were treated with exogenous estrogens for periods up to 27 years (average 7.8). The breasts were thus exposed to estrogen for 2,387 patient-years. The genital exposure was only 1,852 patient-years because 86 patients underwent total hysterectomy and oophorectomy. The author estimates that 18 cases of cancer, either mammary or genital, were to be expected in the group; instead, no cases occurred. On this basis, it is urged that estrogens and progestins be studied more intensively for possible prophylactic effects against mammary and genital cancer.