Molecular and Sociodemographic Colorectal Cancer Disparities in Latinos Living in Puerto Rico.

BACKGROUND

The incidence of sporadic colorectal cancer (CRC) among individuals <50 years (early-onset CRC) has been increasing in the United States (U.S.) and Puerto Rico. CRC is currently the leading cause of cancer death among Hispanic men and women living in Puerto Rico (PRH). The objective of this study was to characterize the molecular markers and clinicopathologic features of colorectal tumors from PRH to better understand the molecular pathways leading to CRC in this Hispanic subpopulation.

METHODS

Microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and and mutation status were analyzed. Sociodemographic and clinicopathological characteristics were evaluated using Chi-squared and Fisher's exact tests.

RESULTS

Of the 718 tumors analyzed, 34.2% ( = 245) were early-onset CRC, and 51.7% were males. Among the tumors with molecular data available ( = 192), 3.2% had MSI, 9.7% had , and 31.9% had mutations. The most common mutations observed were G12D (26.6%) and G13D (20.0%); G12C was present in 4.4% of tumors. A higher percentage of Amerindian admixture was significantly associated with early-onset CRC.

CONCLUSIONS

The differences observed in the prevalence of the molecular markers among PRH tumors compared to other racial/ethnic groups suggest a distinct molecular carcinogenic pathway among Hispanics. Additional studies are warranted.