Histology and its prognostic effect onKRAS-mutated colorectal carcinomas in Korea

KRASmutation is frequently identified in advanced colorectal carcinoma (CRC); however, its prognostic significance and the associated histological features have remained to be clarified. In the present study, the precise histological results and prognostic value ofKRAS-mutated CRCs were investigated in patients from South Korea. A retrospective review of the results fromKRASmutation testing, as well as evaluation of the histology of 310 cases of CRC at various stages, were performed. Cross-tabulation and survival analysis were performed according to theKRASstatus. Patients withKRASmutation more frequently exhibited serrated and papillary architectures (P=0.009 and P=0.014, respectively).KRASmutation was an independent unfavorable prognostic factor for overall survival (OS) according to multivariate analysis (P=0.001), whereas no association was observed with disease-free survival (DFS) (P=0.611). Of note, in the subgroup ofKRAS-mutated carcinomas, the presence of a solid component on histology was associated with less favorable OS (P=0.032). Furthermore, among the wild type cases, patients with a micropapillary component had a worse OS than those who did not (P=0.018). However, no subgroup or specific histological features were associated with DFS. In summary,KRAS-mutated CRCs had a moderate association with particular histological features, and according to theKRASmutational status, there was a certain degree of association between histology and prognosis.