Racial/ethnic disparity in cancer refers to the disproportionate incidence of and/or mortality from various cancers among population groups. In addition to differences in social, lifestyle and structural determinants of health, there is accumulating evidence for a biologic contribution to racial/ethnic disparity in cancer. To understand further the biologic mechanisms underlying racial/ethnic disparity in cancer, the analysis of differential aggregate gene expression and mutation among cancer patients of different population groups is important. Our recently published work reported differential RNA splicing as a critical mechanism underlying prostate cancer aggressiveness and drug response in African American (AA) patients. Here, we use R to analyze the Genomic Data Commons for differential aggregate gene expression (2-fold mean change, p < 0.001, Wilcoxon rank sum test) and TCGASpliceSeq to analyze TCGA for differential RNA splicing (20% median change, percent spliced in) between breast (BRCA, 183 AA and 761 white), colon (COAD, 56 AA and 194 white), squamous and adenocarcinoma lung (LUSC and LUAD, 34 and 57 AA and 392 and 444 white, respectively), and prostate (PRAD, 49 AA and 307 white) cancer specimens from AA and white patients. Our analysis identified 698 differentially expressed genes (DEGs) and 114 alternative RNA splicing events (ARSs) in BRCA, 107 DEGs and 57 ARSs in COAD, 25 and 117 DEGs and 115 and 53 ARSs in LUSC and LUAD, respectively, and 25 DEGs and 71 ARSs in PRAD from AA and white patients. Notably, comparing the lists of DEGs or ARSs from each cancer type with each of the other cancer types yields a minority of overlapping DEGs or ARSs among cancer types, indicating that race-related DEGs and ARSs are largely specific to cancer type. Pathway analysis of DEGs and ARSs reveals that the majority of these genes function in pathways relevant to cancer development and progression, such as programmed cell death, DNA repair, signal transduction, gene expression and metabolism. These analyses increase understanding of molecular mechanisms underlying racial/ethnic disparity in cancer. Upon further study of the function of these variants, such DEGs and ARSs have the potential to become candidates for development of new precision medicine interventions.

Citation Format: Muthana Al Abo, Daniel J. George, Jennifer A. Freedman, Steven R. Patierno. Identification of differentially expressed and spliced genes between breast, colon, lung, and prostate cancer from African American and white patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B050.