Early-onset CRC is often characterized by more advanced stage, poorer cell differentiation, increased prevalence of mucosal and signet ring cell histology, left-sided (ie, distal colon and rectum) location of primary tumors, loss of DNA methylation, increased rate of KRAS and TP53 mutations, and increased proportion of cancer family syndromes.2,3,41,42 These distinguishing characteristics suggest that early-onset CRC may exhibit unique biologic features and a potentially different prognosis when compared with CRC diagnosed among older individuals. This evidence concerns the gene KRAS and colorectal carcinoma.