Risk factors associated with endometrial pathology in premenopausal breast cancer patients treated with tamoxifen

Abstract

Purpose: To evaluate factors associated with endometrial pathology during tamoxifen use in premenopausal breast cancer (BC) patients. Materials and Methods: We reviewed the medical records of premenopausal BC patients treated with tamoxifen who underwent endometrial biopsy with or without hysteroscopy. Clinical characteristics were compared between women with endometrial pa- thology (endometrial hyperplasia or cancer) and those with normal histology or endometrial polyps. Results: Among 284 endometrial biopsies, endometrial hyperplasia was diagnosed in 7 patients (2.5%), endometrial cancer was diagnosed in 5 patients (1.8%), normal histology was noted in 146 patients (51.4%), and endometrial polyp was present in 114 pa- tients (40.1%). When comparing women with endometrial cancer (n=5) to women with normal histology, abnormal uterine bleed- ing was more common (p=0.007), and endometrial thickness was greater (p=0.007) in women with endometrial cancer. Chemo- therapy for BC was also more common in patients with endometrial cancer (p=0.037). When comparing women with endometrial polyps and those with endometrial hyperplasia or cancer, the presence of abnormal uterine bleeding was more common in pa- tients with endometrial hyperplasia or cancer (p<0.001); however, tamoxifen duration and endometrial thickness did not differ significantly between the two groups. Conclusion: In premenopausal BC patients treated with tamoxifen, abnormal uterine bleeding, increased endometrial thickness, and chemotherapy for BC were associated with the occurrence of endometrial cancer. These findings may provide useful infor- mation for gynecologic surveillance and counseling during tamoxifen treatment in premenopausal BC patients.