Endometrial changes in postmenopausal women treated with tamoxifen for breast cancer.

Objective: To evaluate whether risk factors, other than tamoxifen, can be identified for the development of endometrial pathologies in postmenopausal breast cancer patients treated with tamoxifen.
Design: A cross-sectional study.
Setting: Department of Obstetrics and Gynaecology and Oncology Clinic, Sapir Medical Center, Kfar Saba, Israel.
Subjects: 77 asymptomatic postmenopausal women, treated with tamoxifen for breast cancer. Of these, 55 had no endometrial tissue and 22 had endometrial tissue obtained by biopsy.
Main Outcome Measures: Demographic characteristics, health habits, risk factors, vaginal ultrasonographic evaluations of endometrial thickness and texture, and histologic evaluations of endometrial biopsies.
Results: Overall, there was a high rate (29%) of endometrial pathological change among the 77 asymptomatic postmenopausal women. There were no significant statistical differences in the features tested between the two groups.
Conclusion: It is impossible to predict which postmenopausal women will develop pathological endometrial changes after treatment with tamoxifen and thus a routine periodic endometrial sampling-follow up is suggested for all postmenopausal women being treated with this agent.