Differences in single gene expression patterns and signaling pathways between Black and White patients in high grade endometrioid endometrial cancer independent of BMI

Objective: Endometrial cancer (EC) incidence and mortality are increasing with striking racial disparities. Race and obesity are known risk factors for EC, however, their relationship and impact on tumor biology in higher grade endometrioid EC are unclear. The objective of this pilot study was to identify gene- and pathway-level changes in tumors from Black patients compared to White, both in general and in the context of dichotomized BMI.

Methods: A single institution retrospective convenience sample was obtained for grade 2 or 3 endometrioid EC, equally distributed amongst Black and White patients. Tumor samples were analyzed with the Tempus Laboratories xT NGS-based genome profiling test. DESeq2 was applied to identify differentially expressed genes, and then subjected to ingenuity pathway analysis (IPA). Continuous variables were analyzed using unpaired t-tests, and categorical using Chi-squared and Fisher exact tests.

Results: 39 representative cases were identified and analyzed from 2006 to 2021. Baseline clinicopathologic characteristics were similar. 157 genes were differentially expressed in tumors from Black patients compared to White regardless of BMI. IPA identified 81 significantly different pathways between Black and White patients with a BMI < 40 kg/m², and 117 with a BMI ≥ 40 kg/m². Of these, eleven pathways were consistently and significantly activated or deactivated regardless of BMI.

Conclusion: Differences in gene expression and pathway activation in EC exist between race and BMI, which highlights the need for further research to better understand the implications of these differences on endometrioid EC progression, outcomes, and treatment in this historically underserved patient population.