State-Specific Incidence of Endometrial Cancer in the United States by Histologic Subtype Corrected for Hysterectomy Prevalence from 2010 to 2019.

Background: Accurate reporting of state-specific endometrial cancer incidence is important for informing cancer control efforts and may lead to new hypotheses about environmental and/or geographic risk factors. Previous studies have demonstrated the importance of accounting for hysterectomy prevalence when estimating state-level endometrial cancer incidence rates as hysterectomy prevalence varies by geographic region.

Methods: We used the Cancer in North America Public Use Dataset produced by the North American Association of Central Cancer Registries to identify incident endometrial cancer cases among women ≥20 years of age diagnosed from 2010 to 2019. We estimated state-specific hysterectomy-corrected, age-adjusted incidence rates overall and by histology. State-specific hysterectomy prevalence data were obtained from the Behavioral Risk Factor Surveillance System.

Results: Hysterectomy prevalence was highest in Southern and Midwestern states and lowest in the Northeast. Although uncorrected endometrial cancer incidence rates were highest in the Northeast, hysterectomy-corrected rates were highest in states within the Midwest and Appalachia. Geographic patterns of the hysterectomy-corrected incidence of endometrioid cancer resembled those of endometrial cancer overall. In contrast, corrected rates of non-endometrioid cancer were highest in the South and in certain states within the Northeast and Midwest. There was no overlap in the top 10 states with the highest rates of endometrioid and non-endometrioid cancers, respectively.

Conclusions: State-specific, hysterectomy-corrected incidence rates of endometrial cancer vary by histology, suggesting potential differences in behavioral, sociodemographic, and/or environmental exposures at the state level.

Impact: This study presents an accurate assessment of US endometrial cancer rates and emphasizes the importance of hysterectomy correction for geographic comparisons.