[Risk of endometrial hyperplasia and carcinoma in breast cancer patients receiving adjuvant tamoxifen].

The antiestrogen drug tamoxifen, which is widely used in adjuvant hormone therapy of breast cancer, presents certain risk of causing hyperplasia and endometrial carcinoma. Our clinical data on 1,969 breast cancer patients (stage I-III) (tamoxifen--947; control--1,022) showed a double rise in endometrial carcinoma risk in cases receiving hormone therapy. Endometrial carcinoma incidence in tamoxifen-treated patients was 3% while in the untreated ones--1.6% (p < 0.05). According to the endometrial tissue study in 439 breast cancer patients, proliferative effect of tamoxifen in the form of endometrial hyperplasia was 5--6 times in tamoxifen users. Meanwhile, endometrial carcinoma and hyperplasia risk increased during a much longer exposure to tamoxifen and in combination with such factors as obesity, diabetes mellitus, uterine myoma and estrogen-type colpocytological response. Hence, breast cancer patients need to undergo dynamic follow-up of the endometrium including ultrasonic examination of the small-pelvis organs and cytological study of ecto- and endocervical smears and endometrial aspirates.