Histopathologic effects of tamoxifen on the uterine epithelium of breast cancer patients: analysis by menopausal status.

We evaluated the histopathologic changes of the uterine epithelium in 73 breast cancer patients with tamoxifen stratified by menopausal status. Clinicopathologic data at the time of breast cancer diagnosis and endometrial sampling were analyzed and compared with 122 breast cancer patients not receiving the drug. The incidence of endocervical and/or endometrial polyps was increased in tamoxifen-treated postmenopausal patients compared with untreated patients, 43% (25 of 58) and 24% (16 of 68), respectively (odds ratio=2.46, P=0.02). In contrast, there was no increase in polyps in premenopausal tamoxifen-treated patients. This finding suggests that the effects of tamoxifen on the endometrium may vary with menopausal status.