Decreasing secondary primary uterine cancer after breast cancer: A population-based analysis

Objective. To report population-based statistics of women with uterine cancer and a history of prior breast cancer. Methods. This is a retrospective study examining the Surveillance, Epidemiology, and End Results Program between 1973 and 2013. Temporal trends, clinico-pathological characteristics, and survival of women with uterine cancer who had prior breast cancer were assessed. Results. Among 237,686 women with uterine cancer, 8235 (3.5%) women had antecedent breast cancer. The number of women with uterine cancer who had a history of breast cancer increased between 1975 and 1989 (21.1-fold relative risk-increase, P < 0.001) and then decreased between 1989 and 2013 (relative risk reduction [RRR] 11.1%, P = 0.008). The number of uterine cancer among breast cancer survivors decreased between 1990 and 2008 (RRR, 86.0%, P < 0.001). Women with uterine cancer and antecedent breast cancer were more likely to be older and white compared to those without a history of breast cancer (P < 0.05). Uterine tumors after breast cancer were more likely to have serous (10.5% versus 5.7%), carcinosarcoma (8.9% versus 4.4%), or clear cell (2.1% versus 1.2%) histology and present with grade 3 (30.8% versus 21.5%) and stage I disease (64.6% versus 62.5%) compared to tumors in women without breast cancer (all, P < 0.05). After propensity score matching, women with uterine cancer after breast cancer were less likely to die from uterine cancer (adjusted hazard ratio [HR] 0.675) but more likely to die from other malignancies (adjusted-HR 4.090), particularly breast cancer, and had poorer overall survival (adjusted-HR 1.154) compared to those without breast cancer. Conclusion. The diagnosis of uterine cancer after breast cancer is decreasing. While uterine tumors following breast cancer are associated with high-risk tumor characteristics, women with uterine cancer after breast cancer are more likely to die from other malignancies. (C) 2019 Elsevier Inc. All rights reserved.