Guo TA, et al. - Given that patients with colorectal cancer (CRC) are routinely assessed for mutations of KRAS, NRAS, BRAF and DNA mismatch repair (MMR) status, researchers sought for the respective clinicopathologic features and prognostic significance in specific stages and related detection strategies via retrospectively analyzing 1834 patients with stage I–IV colorectal adenocarcinoma. KRAS, NRAS, and BRAF had mutation rates of 46.4%, 3.2%, and 3.5%, respectively, and the mismatch repair had gene deletion (dMMR) rate of 5.6%. In a multivariate analysis, a high KRAS mutation rate was noted in correlation to female sex, advanced age, tumor type histology, mucinous carcinoma and positive tumor deposits. Female sex, poor differentiation, lymphovascular invasion and positive tumor deposits were correlated to a high BRAF mutation rate. Low age, large tumor size, poor differentiation, stage I-III were identified as factors associated with high dMMR rates. KRAS mutation, BRAF mutation and dMMR were observed in independent correlation to tumor site. In stage IV tumors but not in stage I–III, shorter overall survival (OS) was noted in independent correlation to KRAS and BRAF mutations. In stage I–II tumors, shorter OS was noted to be independently associated with NRAS mutation. In stage III tumors, longer OS was noted in independent correlation to dMMR.