Racial and ethnic differences in tumor characteristics among endometrial cancer patients in an equal-access healthcare population.

Purpose: There are racial and ethnic differences in endometrial cancer incidence and mortality rates; compared with Non-Hispanic White women, Black women have a similar incidence rate for endometrial cancer, but their mortality is higher. Pacific Islander women may also have worse outcomes compared to their White counterparts. We assessed tumor characteristics and adjuvant therapy by racial and ethnic group among endometrial cancer patients treated within the Military Health System, an equal access healthcare organization.

Methods: We retrospectively identified women diagnosed with invasive endometrial cancer among US Department of Defense beneficiaries reported in the Automated Central Tumor Registry database (year of diagnosis: 2001-2018). We compared tumor characteristics and receipt of adjuvant therapy across racial and ethnic groups using Chi-square or Fisher tests. Hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of all cause mortality were calculated using Cox proportional hazards regression models adjusting for age at diagnosis, adjuvant therapy, histology and stage.

Results: The study included 2574 endometrial cancer patients [1729 Non-Hispanic White, 318 Asian, 286 Black, 140 Pacific Islander and 101 Hispanic women]. Among all cases, a higher proportion of Black patients had non-endometrioid histology (46.5% versus ≤ 29.3% in other groups, P < 0.01) and grade 3-4 tumors (40.1% versus ≤ 29.3% in other groups, P < 0.01). In multivariable Cox models, compared with Non-Hispanic White cases, Black endometrial cancer patients had a higher mortality risk (HR 1.43, 95% CI, 1.13-1.83). There was no difference in mortality risk for other racial and ethnic groups.

Conclusion: Black patients with endometrial cancer presented with more aggressive tumor features and they had worse overall survival compared with patients in other racial and ethnic groups. Further study is needed to better direct preventive and therapeutic efforts in order to correct endometrial cancer disparities in the future.