Colorectal Cancer Disparities in Latinos: Genes vs. Environment

Abstract

Colorectal cancer (CRC) is potentially preventable, yet it remains the fourth most common cause of cancer-related death worldwide. CRC is currently the first and third leading cause of cancer-related death in Puerto Rico and in the United States (US), respectively. The CRC racial/ethnic health disparities reported among mainland US Hispanics and Puerto Rican Hispanics may result from a combination of environmental and genetic factors including nutrition, genetic predisposition, and gut microbiome composition. The incidence of CRC among Hispanics who move to the US is higher than in their native countries, supporting the hypothesis that environmental exposure is a major risk factor for the development of CRC. In addition to disparities in CRC incidence and mortality, an age-associated CRC disparity has been noted among Hispanics; the number of CRC cases among Hispanics <50 years of age (early-onset CRC) has increased dramatically in both mainland US and Puerto Rican Hispanics. Our current work focuses on understanding the factors that contribute to decreased CRC survival among Puerto Rican Hispanics, the genetics associated with early onset CRC, the association of genetic ancestry and specific SNPs identified through GWAS with CRC risk in this population, and the association between dietary patterns and gut bacterial toxins with colorectal neoplasia risk. In sum, our work is providing a better understanding of the underlying factors contributing to CRC health disparities among Puerto Rican Hispanics.