Tumor Immune Microenvironment Differences Associated With Racial Disparities in Pancreatic Cancer

Racial differences in antitumoral immunity have been identified in a variety of cancers and may contribute to survival disparities, but limited data exist exploring the molecular differences in pancreatic adenocarcinoma (PDAC). Using racially diverse PDAC datasets, we explored biologic differences that may drive disparities between African American (AA) and European American (EA) PDAC patients.

Genomic PDAC mutational data was analyzed for mutational differences based on race. In a separate cohort, surgical PDAC specimens were processed for both tissue microarray and multiplex gene expression analysis using NanoString.

Of the 4679 patient samples in the mutational dataset, AA PDAC patients had significantly more TP53 mutations compared to the EA cohort. The tissue microarray included 12 AA and 41 EA surgically resected treatment-naive PDAC samples. NanoString analysis revealed significant differences between AA and EA groups in immunologic gene annotations (P < 0.05).

In the present study, we demonstrated that across racially diverse datasets, there exist molecular and microenvironmental differences between AA and EA patients that may contribute to cancer survival disparities. Defining molecular differences underlying PDAC racial disparities is an essential step in advancing care and improving outcomes for AA patients that suffer worse survival across cancer types.