Endometrial histologic changes in post-menopausal breast cancer patients using tamoxifen.

OBJECTIVE: The aim of this study was to evaluate the effect of tamoxifen on the endometrium of post-menopausal women with breast cancer and to examine the relationship between ultrasonography, hysteroscopy and histopathologic changes. METHOD: Included in this longitudinal study were 303 post-menopausal women taking 20 mg daily of tamoxifen. Hysteroscopy was performed in 83 patients with an endometrial thickness of only >or=5 mm and 34 with vaginal bleeding also. Forty-five asymptomatic patients (control group) underwent hysteroscopies. RESULT: The most frequent outcome in patients with endometrial thickness of only >or=5 mm was an atrophic endometrium in an empty cavity (79.5%) whereas simple hyperplasia (35.3%) was found in women with vaginal bleeding. Carcinoma was diagnosed in seven cases (5.9%). In the control group, no endometrial cancer was found. CONCLUSION: This study suggests that patients with a thickness >5 mm should be offered a whole hysteroscopic evaluation, whenever bleeding is reported.