Long-term follow-up of postmenopausal breast cancer patients following discontinuation of tamoxifen therapy

Background: There is a need to evaluate the extent of endometrial pathologies that might develop in postmenopausal breast cancer patients following discontinuation of tamoxifen (TAM) therapy. Methods: The medical records of 153 postmenopausal breast cancer patients who remained untreated following discontinuation of tamoxifen therapy were evaluated for various clinical features, for endometrial thickness measurements, as detected by transvaginal ultrasonography, and for various endometrial pathologies detected. The last endometrial thickness measurement performed before discontinuation of tamoxifen was compared with endometrial thickness measured following discontinuation of tamoxifen. Results: Patients were followed for 37.5 ± 31.3 months. There was a gradual and significant decrement of endometrial thickness measured at the last ultrasonographic study performed before cessation of tamoxifen, compared to that observed in all four ultrasonographic studies performed following discontinuation of tamoxifen (P = 0.001). Endometrial thickness gradually and significantly decreased in correlation with the time intervals of the four ultrasonographic studies performed following discontinuation of tamoxifen (P = 0.001). Overall, 40 hysteroscopies were performed in 38 (24.8%) patients. No tissue was obtained in 18 (11.8%) patients. Overall endometrial pathologies were diagnosed in 22 (14.4%) patients. Benign endometrial polyps were the most frequent endometrial pathology recovered: 17 (11.1%) patients. No endometrial malignancy was diagnosed. The rate of endometrial pathologies considerably decreased with the extension of time following discontinuation of tamoxifen therapy. Conclusions: Long-term follow-up of postmenopausal breast cancer patients who remained untreated following discontinuation of TAM therapy did not reveal any malignant endometrial pathology. Only few benign endometrial pathologies were diagnosed, which became fewer in time.