Clinical and Genomic Characteristics of Mexican Patients with Early Onset Gastric Adenocarcinoma.
BACKGROUND: Gastric cancer is a leading cause of cancer-related deaths in Mexico, with a rising incidence of early onset gastric cancer (EOGC) in young adults. This single-center study aimed to describe the clinical and mutational characteristics associated with EOGC in Mexican patients, based on an age cutoff of 50 years. METHODS: Clinical information was retrieved from electronic records and compared between EOGC and late-onset gastric cancer (LOGC). Whole exome sequencing data from 50 patients were analyzed and compared between both groups to elucidate the genomic overview of EOGC. RESULTS: Clinical data from 2,034 patients were analyzed. Of those, 35.69% had EOGC, with higher proportions of women (52.50%), diffuse histology (74.38%), signet ring cells (79.90%), and advanced stages (IVB: 79.58%; all p <0.001). Multivariate analysis in young patients identified ECOG (hazard ratio [HR]: 1.49) and clinical stage (HR: 1.78) as independent prognostic factors that increased mortality risk. However, the presence of Helicobacter pylori (HR: 0.76) and participation in genetic counseling (HR: 0.61) were independent prognostic factors that decreased the mortality risk. The molecular profile of Mexican patients demonstrated a high prevalence of CDH1 mutations and SBS44 mutational signatures. CONCLUSION: Mexican patients demonstrated higher rates of EOGC compared to other ethnicities. Genetic counseling enhances the overall survival of patients with EOGC; efforts should be made to incorporate it into routine practice. Molecular profiling revealed high CDH1 and SBS44 prevalence; however, sample size limitations warrant caution.