This study was undertaken with regard to the gonadotropin theory of ovarian cancer advocated in the literature and was designed to disclose specific features of ovarian morphology in carriers of the BRCA1 gene mutation. We enrolled 171 patients and divided them into two groups: A (n=90)--operated for breast cancer (30 patients with and 60 without the BRCA1 mutation); B (n=81)--with the BRCA1 mutation qualified for preventive adnexectomy. According to the authors' classification described herein, some patients without the BRCA1 mutation retained "signs of estrogenization" in menopausal ovaries, revealing the role of estrogens as a factor promoting mammary carcinogenesis in these patients. A tendency to premature menopause was observed in BRCA1 mutation carriers of groups A and B as evidenced by the final menorrhea appearing at a younger age and almost total absence of "signs of estrogenization" in menopausal ovaries. It is concluded from these findings that earlier menopause in carriers of the BRCA1 mutation is associated with hypergonadotropic activity and may predispose to ovarian cancer at younger age.