Malignant endometrial polyps in postmenopausal breast cancer tamoxifen- treated patients

Background. Endometrial polyps are the most common endometrial pathology described in association with postmenopausal tamoxifen exposure. It is generally accepted that the occurrence of malignancy in endometrial polyps among healthy women is up to 0.5%. However, no one has yet described the incidence of this malignant transformation among postmenopausal breast cancer tamoxifen-treated patients. Objective. The aim of this study was to study the exact rate of malignant changes in endometrial polyps recovered from postmenopausal breast cancer tamoxifen-treated patients. Methods. We reviewed the pathological results and medical records of all postmenopausal breast cancer patients in whom endometrial polyps were recovered following at least 6 months of tamoxifen treatment in our institute. We also looked for the rate of malignant changes in polyps recovered from all healthy postmenopausal controls with endometrial polyps in our institute during the period of the study. Results. Two (3.0%) of 67 endometrial polyps recovered from postmenopausal breast cancer tamoxifen-treated patients revealed malignant features. None of the clinical variables tested, including risk factors for endometrial cancer, was significantly different between the groups. In the controls only 5 (0.48%) of 1034 polyps were malignant. Conclusion. Up to 3.0% of endometrial polyps recovered from postmenopausal breast cancer tamoxifen- treated patients may show malignant changes. This rate is higher than that found in our controls as well as that reported in the general female population.