Analysis of Risk Factors for Secondary Endometrial Cancer-Related Death: A SEER-Based Study

Purpose: The aim of this study was to analyze the survival of patients with endometrial cancer diagnosed after a prior cancer and identify risk factors of endometrial cancer death in this population. Methods: Totally 1371 women diagnosed with second primary endometrial cancer (SPEC) between 2004 and 2015 were identified using the SEER database. Clinicopathological characteristics were collected, and Fine and Gray regression model was employed to assess the impact of treatment for the first primary cancer (FPC) and SPEC on the mortality of endometrial cancer patients. After propensity score matching (PSM), patients diagnosed with single primary endometrial cancer and SPEC between 2004 and 2015 were included as the second cohort. Kaplan-Meier and Cox survival risk models were used to assess the influence of previous cancer history on survival. Results: Patients previously diagnosed as lung cancer exhibited the lowest overall survival (OS). A diagnostic interval of >= 3 years was significantly associated with higher mortality from SPEC compared with that <3 years. Surgical treatment for SPEC was linked to a reduced risk of endometrial cancer-specific mortality (ECSM) and non-ECSM. Conversely, radiotherapy and chemotherapy were associated with an increased risk of ECSM. The 1-, 3-, and 5-year OS rates of patients with SPEC were significantly lower than those with single primary endometrial cancer whether before or after PSM. Univariate and multivariate analyses further demonstrated that endometrial cancer, either as FPC or SPEC, was independently associated with an increased risk for endometrial cancer-specific survival (ECSS) and OS. Conclusion: Chemotherapy and radiotherapy for SPEC can elevate the risk of ECSM. Whether as FPC or SPEC, endometrial cancer is demonstrated to be a significant independent risk factor for ECSS and OS.