Long-term Patterns of Excess Mortality among Endometrial Cancer Survivors

Abstract

Abstract Purpose of the study: Examining long-term patterns of mortality among cancer survivors compared to the general population may inform planning for surveillance and follow-up care. We investigated excess mortality after endometrial cancer using conditional relative survival estimates and standardized mortality ratios (SMRs). Methods: Women diagnosed with endometrial cancer during 2000–2017 (N = 183,153) were identified in the Surveillance, Epidemiology, and End Results (SEER) database. SMRs were calculated as observed deaths among endometrial cancer survivors over expected deaths among demographically similar women in the general U.S. population. Five-year relative survival was estimated at diagnosis and each additional year survived up to 12 years post-diagnosis, conditional on survival up to that year. Results: For the full cohort, 5-year relative survival was 87.7%, 96.2%, and 97.1% at 1, 5, and 10 years post- diagnosis. respectively. Conditional 5-year relative survival first exceeded 95%, reflecting minimal excess mortality compared to the general population, at 4 years post-diagnosis overall, but occurred later for Black women (8 years) compared to White (4 years), and also later for women with regional/distant stage, grade 3 disease, or non- endometrioid histology. The overall SMR for all-cause mortality decreased from 5.90 (95% CI: 5.81–5.99) in the first year after diagnosis to 1.16 (95% CI: 1.13–1.19) at 10+ years; SMRs were consistently higher for non-White women and those with higher stage or grade disease. Conclusions: Overall, endometrial cancer survivors had only a small survival deficit beyond 4 years post- diagnosis. However, excess mortality was greater in magnitude and persisted longer into survivorship for Black women and those with more advanced disease.