Anovulation and increased androgenic activity as breast cancer risk in women with fibrocystic disease of the breast.

The urine of 26 otherwise healthy women with fibrocystic disease of the breast was assayed by gas chromatography for testosterone and androstanediol (5alpha-androstane-3alpha, 17beta-diol), the major metabolite of dihydrotestosterone. The mean values for both androgens were significantly higher than in 18 normal women in the same age range. Sixteen of the 26 fibrocystic disease patients also had endometrial hyperplasia. Since the endometrial specimen was obtained in the premenstrual period, the presence of hyperplasia proved that the menstrual cycle in over two-thirds of the fibrocystic disease patients was nonovulatory.