Sporadic early-onset colorectal carcinoma is a distinct clinicopathological and molecular entity

Sporadic early onset colorectal carcinoma (EOCRC) is a growing problem that remains poorly understood. Clinical specificities and mechanisms of tumorigenesis might be relevant to both diagnosis and treatment. In this prospective study, clinicopathological features, genomic and gene expression profiles of sporadic EOCRC were compared to other well defined groups of CRC. Seventy selected patients were divided into 4 groups according to age (< 45 or > 60 years) and mismatch repair status. Mutations of key genes involved in colorectal carcinogenesis (P53, KRAS, BRAF, PIK3CA) were detected and the methylator phenotype (CIMP) established. Gene expression profiles (GEP) were obtained using pangenomic Affymetrix GeneChip.