Tamoxifen-related uterine carcinosarcomas occur under/after prolonged treatment: Report of five cases and review of the literature

The risk of tamoxifen-related endometrial adenocarcinoma is well established with daily dose and treatment duration of adjuvant tamoxifen as risk factors. There have also been in the past years, a few descriptions of uterine nonepithelial malignancies occuring after tamoxifen. We describe five recent cases of uterine carcinosarcomas occurring under/after tamoxifen administered in an adjuvant setting. None of these patients had received prior pelvic radiation therapy. Their median age at the diagnosis of breast cancer was 58 years (41-68), and 69 years (50-84) at the diagnosis of uterine carcinosarcoma. The median length of exposure to tamoxifen was 9 years (5-20), and the median time from the initiation of tamoxifen to the diagnosis of the uterine malignancy (latency period) 9 years (7-20). All patients presented with an advanced stage (IIA-IVA). Our data, together with those of the literature, plead for a causal role of a prolonged exposure to tamoxifen on the subsequent development of uterine carcinosarcoma. The long latency period observed even in patients receiving only 5 years of treatment leads us also to consider a prolonged gynecologic follow-up of the patients.