Sonographic, hysteroscopic, and histologic evaluation of the endometrium in postmenopausal women with breast cancer receiving tamoxifen

Study Objective. To evaluate the estrogenic effects of tamoxifen on the end ometrium in postmenopausal women with breast cancer. Design. Consecutive study (Canadian Task Force classification II-2). Setting. University-affiliate hospital. Patients. Thirty-three women. Interventions. All patients underwent transvaginal sonography (TVS) and col or flow Doppler of endometrial vessels, hysteroscopy, and, if necessary, en dometrial biopsy or other operative hysteroscopic procedures. Measurements and Main Results. In four women the endometrium was thin on TV S and atrophic at hysteroscopic assessment. In 29 women with thick endometr ium on TVS, hysteroscopy and endometrial biopsy showed atrophy (11 patients ), hyperplasia (5), polyps (11), and well-differentiated adenocarcinoma (2) . The two endometrial cancers were present in women with uterine bleeding. In women with positive histologic findings, the endometrium was significant ly thicker (p = 0.04) and duration of tamoxifen therapy longer than in thos e with negative findings, although this was not statistically significant ( p = 0.067). Conclusion. We believe regular assessment of the endometrium by TVS should be performed in postmenopausal patients at the start of the tamoxifen thera py, and hysteroscopy in women with a thick endometrium or postmenopausal bl eeding. We believe that patients with thin endometrium on TVS at the beginn ing of tamoxifen therapy, who have no abnormal uterine bleeding should be s creened with these examinations for 2 years.