High cardiovascular disease mortality after endometrial cancer diagnosis: Results from the Surveillance, Epidemiology, and End Results (SEER) Database

Obesity is a strong risk factor for developing endometrial cancer and cardiovascular disease (CVD); consequently, understanding CVD mortality among endometrial cancer survivors is important. We analyzed Surveillance, Epidemiology and End Results Program data for 157,496 endometrial cancer cases diagnosed between 1988 and 2012. We calculated standardized mortality ratios (SMRs) for CVD and all-cause mortality comparing endometrial cancer cases and general population women. We categorized women into one of three prognostic groups (excellent, intermediate and poor) based on tumor characteristics. Cumulative incidence function curves were plotted to visualize absolute mortality risk in the presence of competing risks. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression for cause-specific mortality. Deaths were as follows: endometrial cancer 40.6%, CVD 20.5%, other cancers 18.7% and other causes 20.3%. Women with endometrial cancer were more likely to die from CVD (age-adjusted SMR = 8.8, 95% CI = 8.7-9.0) and all causes (age-adjusted SMR = 15.9, 95% CI = 15.8-16.0) compared to general population women. In case-only analyses, higher CVD mortality was associated with older age, Black ethnicity and lack of surgical treatment. Poor prognosis cancers (non-endometrioid histology and late stage) were related to higher mortality from each cause, with the highest HRs observed for endometrial cancer-specific mortality. Among women diagnosed with excellent prognosis tumors (endometrioid, well-differentiated and early stage), absolute risk of CVD mortality surpassed endometrial cancer-specific mortality 5 years after diagnosis. Women diagnosed with common forms of endometrial cancer have a high CVD burden. After diagnosis, cardiovascular health should be emphasized for these women to reduce mortality.