Advanced clinical stage is a problem, predictive molecular markers are a solution: a study of colorectal cancer in a Mexican adult cohort

Background: Colorectal carcinoma is the 3rd most common cause of death due to cancer worldwide. Its complexity is mainly explained by its molecular heterogeneity. Scarce information exists of the molecular profile of CRC in the Mexican population. Objective: We developed a retrospective study of cases with colorectal carcinoma from a cohort of Mexican patients to evaluate the presence of predictive molecular markers. Method: KRAS, NRAS and mismatch repair genes were analyzed in cases of colorectal carcinoma. Results: The most frequent location was the rectum. The majority had an invasive colorectal carcinoma with more than 90% being intestinal adenocarcinoma. Eighty percent of the cases were moderately differentiated, and the majority presented an advanced clinical stage. KRAS was mutated in half of the cases. Mutations in the rest of the genes were identified in less than 5% of the cases. When analyzed according to molecular predictive markers, there was no difference in the follow up duration, death percentage nor in the characteristics of the tumor (site, differentiation and morphology). Conclusions: There is a high prevalence of advanced stage CRC in Mexico. Characterizing the predictive molecular biomarkers in CRC expands and optimizes the therapeutic strategies.