Racial/Ethnic Disparities in Genomic Sequencing

MPH alumna Tiffany Chan and Assistant Professor of Epidemiology and Biostatistics, Levi Waldron assess disparities in The Cancer Genome Atlas.

It is probable, but poorly understood, that ethnic diversity is related to the pathogenesis of cancer, and may have an impact on the generalizability of findings from cancer genomics studies to racial minorities. This study analyzes the racial/ethnic composition of participants in The Cancer Genome Atlas (TCGA), a nation-wide project to perform comprehensive genomics analysis of common cancer types, and to improve on available therapies. It finds that, despite approximately proportional relative sample size of many demographic minorities, whites are over-represented whereas Asians and Hispanics are under-represented. Furthermore, the absolute sample size of all minority groups is inadequate to capture even relatively common somatic mutations that are specific to those groups. Despite the important benefits in patient outcome that continue to be gained from genomic sequencing, dedicated efforts are needed to avoid widening the already pervasive gap in cancer health care disparities

Dr. Waldron notes that, “15 years after the sequencing of the first human genome, we are now sequencing thousands of cancer genomes to understand which mutations lead to disease, and how they can be treated. But this study shows that these projects tend to include too few minorities to provide those groups the same potential benefits, so they could widen already existing disparities in outcomes.”

Spratt DE*, Chan T*, Waldron L, Speers C, Feng FY, Ogunwobi OO, Osborne JR: Racial/Ethnic Disparities in Genomic Sequencing. JAMA Oncol 2016. *equal contribution.