In the US, the majority of
cancer samples analyzed are from white people, leading to biases in racial and ethnic treatment outcomes.
Colorectal cancer (CRC) incidence and mortality rates are high in Alabama African Americans (AAs) and Oklahoma American Indians (AIs). We hypothesized that differences between racial groups may partially explain these disparities. Thus, we compared transcriptomic profiles of
CRCs of Alabama AAs, Oklahoma AIs, and white people from both states. Compared to
CRCs of white people,
CRCs of AAs showed (a) higher expression of
cytokines and vesicle trafficking toward modulated antitumor-immune activity, and (b) lower expression of the ID1/BMP/SMAD axis, IL22RA1, APOBEC3, and
Mucins; and AIs had (c) higher expression of
PTGS2/COX2 (an
NSAID target/pro-oncogenic
inflammation) and splicing regulators, and (d) lower
tumor suppressor activities (e.g., TOB2, PCGF2, BAP1). Therefore, targeting strategies designed for white CRC patients may be less effective for AAs/AIs. These findings illustrate needs to develop optimized interventions to overcome racial CRC disparities.