ULTRASONOGRAPHIC APPEARANCE OF ENDOMETRIUM IN POSTMENOPAUSAL BREAST-CANCER PATIENTS RECEIVING TAMOXIFEN

Objectives: To assess the ultrasonographic appearance and associated p athological changes of the endometrium in postmenopausal breast cancer patients with tamoxifen therapy. Study design: Forty-eight postmenopa usal breast cancer patients receiving 20 mg/day tamoxifen for 6-84 mon ths (mean 29) and 38 control breast cancer patients without any hormon al treatment were examined by transvaginal ultrasonography and endomet rial biopsy. Any thickening of the endometrium with cystic formations or homogeneous endometrial thickening > 10 mm detected by ultrasonogra phy was defined as abnormal endometrial appearance, Homogenous endomet rial thickening < 10 mm without cystic formations was accepted as norm al. Statistical analysis was performed using the Student's t-test and Mann-Whitney U test. Results: The two groups were similar in age and m enopausal period, The patients on tamoxifen therapy had a thicker endo metrium(8.6 +/- 6.6 mm) than the non-treated women (4.8 +/- 3.1 mm), w hich was found to be a statistically significant difference (P < 0.01) . The sonographic evaluations showed abnormal endometrial appearance i n 8 cases of tamoxifen treated women while the others revealed homogen eous thickness < 10 mm without cystic formations or a thin linear echo with or without fluid in the endometrial cavity. All 8 patients with cystic appearance had endometrial thickness > 10 mm. Only 1 patient ha d endometrial cancer on biopsy and no pathology was observed in the re maining 7 patients. In the control group, only 1 patient had abnormal ultrasonographic finding who had insufficient endometrial tissue on bi opsy. Conclusions: Tamoxifen can produce a sonographic image of the en dometrium that resembles endometrial neoplasia, It is suggested that t he discrepancy between the sonographic findings and histology may be t he result of the stromal edema of the endometrium from tamoxifen treat ment. Until more data are gathered, all postmenopausal breast cancer p atients who are being treated with tamoxifen should have a periodic ul trosonographic examination and those presenting with a sonogram sugges tive of endometrial pathology should undergo biopsy.