Background: The incidence of endometrial cancer in the United States has increased, disproportionately affecting medically underserved women of lower socioeconomic backgrounds and minority ethnicities. Previous studies have shown that women with endometrial cancer residing in rural communities have a worse prognosis and lower survival rate than those of urban settings, but few have evaluated the relationship between location of residence and stage at diagnosis. We aim to determine whether rural versus urban residence influences stage of endometrial cancer at diagnosis.

Methods: Data from the National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) database from 2000-2019 was included. Eligible participants were women ages 18 and older with a diagnosis of endometrial cancer (ICD-0-3 C54.1). Rural versus urban population was the exposure variable, with stage of the endometrial cancer at diagnosis (localized vs regional / distant) as the outcome. Statistical analysis methods included exploratory and descriptive to characterize the population, Chi-Square test to determine the unadjusted association of the exposure and outcome, and logistic regression to calculate the unadjusted and adjusted odds ratio (OR) and 95% confidence intervals (CI).

Results: 192,973 women were included (59.1% aged 60+, 70.0% of white race, 88.5% residing in urban areas). Advanced stage of diagnosis of endometrial cancer was seen in 28.1% of women and was more frequent among those residing in urban areas, aged 80+, of Non-Hispanic Black ethnicity, or with Type 2 histology (p<0.001). The unadjusted odds of being diagnosed at regional/distant stage decreased by 6% in individuals of rural areas compared to those in urban areas (OR 0.94, (95% CI 0.91-0.97, p<0.001)). When adjusting for confounders, this risk became nonsignificant (OR 0.99, 95% CI, 0.95-1.02,) p=0.41)). Women aged 80+, of Non-Hispanic Black ethnicity, or with Type 2 histology had an increased odds of advanced stage at diagnosis of 41%, 45%, and nearly 400% respectively.

Conclusion: Residential status (urban vs rural) was not associated with the stage of endometrial cancer at diagnosis. However, our study found significant associations between advanced stage and age, race, and histology type, therefore suggesting the presence of additional health disparities affecting the diagnosis of endometrial cancer.