Genomic Landscape of Colorectal Cancer in a Multi-Ancestry Cohort

Elucidating the tumor mutational landscape of colorectal cancer (CRC) in admixed and ancestrally diverse populations is essential to enable precision medicine advancements that benefit individuals of all backgrounds. This study draws from the Latino Colorectal Cancer Consortium (LC3) and other prior initiatives to characterize and examine the somatic mutational patterns of colorectal tumors in Hispanic/Latino/Latina patients (henceforth referred to as Latino) as compared to other racial and ethnic populations. It includes paired tumor-normal whole-exome sequencing from 718 patients with primary CRC (128 Latino and 469 non-Latino individuals) to investigate the associations between somatic mutational features and both self-reported ethnicity and genetic ancestry. Somatic mutations and inherited variants were called, and global genetic ancestry proportions (African, Asian, European, Native American) were estimated from inherited variants using ADMIXTURE based on reference samples from the 1000 Genomes Project (1KGP) and the Population Architecture using Genomics and Epidemiology (PAGE) Study. Associations between genetic ancestry and gene-level mutational status, microsatellite instability status, and tumor mutational burden were estimated using logistic regression, after adjusting for age at diagnosis, sex, tumor location, and stage.]]>
All patients selected for the study were diagnosed with primary colorectal adenocarcinoma. Biospecimens from these participants that represented colorectal polyps, metastatic CRC lesions, recurrent lesions, or non-colorectal cancers were excluded.]]>