Ovarian cysts in postmenopausal tamoxifen-treated breast cancer patients with endometrial thickening detected by transvaginal sonography

OBJECTIVE: To investigate the frequency of ovarian cysts in tamoxifen-treated postmenopausal breast cancer patients with endometrial thickening detected by transvaginal sonography. METHODS: Medical records and transvaginal sonographies of 38 postmenopausal women treated for breast cancer with adjuvant tamoxifen therapy who had undergone endometrial sampling due to abnormal endometrial thickness were reviewed retrospectively. RESULTS: During the study period five of 38 tamoxifen-treated postmenopausal patients (13.2%) had ovarian cysts. The mean tamoxifen treatment interval of the patients with an ovarian cyst was 22.4 +/- 18.4 months (p = 0.17). The mean endometrial thickness of the patients with an ovarian cyst was 12.6 +/- 5.9 mm (p = 0.17). Endometrial biopsy detected six cases of abnormal endometria, including endometrial carcinoma (n = 1), endometrial polyp (n = 1) and simple endometrial hyperplasia without atypia (n = 4). Three patients with ovarian cysts underwent laparatomy revealing simple cysts on histopathological examination. Two patients with ovarian cysts declined laparatomy and are currently under follow-up. CONCLUSION: Ovarian cysts a common side-effect of tamoxifen treatment in postmenopausal tamoxifen-treated breast cancer patients. Transvaginal sonography should be performed to detect any concomitant endometrial pathology.