Aggressive Right-Sided Colon Cancer in a Young Adult: Triple-Whammy Mutations (POLE, KRAS, BRCA1/2) Highlight Emerging Genetic Associations

BRCA mutations are well established in breast and ovarian cancers and increasingly recognized in colorectal cancer (CRC), particularly BRCA1 . Dual BRCA1/2 pathogenic variants in CRC remain exceptionally rare. We report a case of early-onset CRC in a young male harboring pathogenic variants in BRCA1 , BRCA2 , and POLE , with no personal or familial cancer history. This mutational triad suggests convergence of homologous recombination deficiency and impaired DNA proofreading, resulting in a hypermutated phenotype. The case may represent a novel molecular CRC subtype and underscores the importance of broad-panel germline testing in young patients, with implications for poly (ADP‑ribose) polymerase and immune checkpoint inhibitor therapy.