Mismatch repair deficiency and mutations of KRAS,NRAS,PIK3CA and BRAF genes in colorectal micropapillary carcinoma
Purpose To investigate the clinicopathological and molecular features of colorectal micropapillary carcinoma(MPC),and to provide evidence for the diagnosis and individu-al treatment of colorectal MPC.Methods The clinicopathologi-cal and molecular data of 461 patients with colorectal cancer were collected retrospectively,including 56 cases of colorectal MPC and 405 cases of colorectal adenocarcinoma not otherwise specified(NOS).The expression of 4 mismatch repair proteins(MLH1,PMS2,MSH2,MSH6)and p53 protein was detected by immunohistochemistry.The hot spot mutations of KRAS,NRAS,PIK3CA and BRAF genes were detected by ARMS-PCR,to analyze the difference of clinicopathological and molec-ular features between colorectal MPC and adenocarcinoma NOS.Results The vessel invasion rate and lymph node metastasis rate of colorectal MPC were significantly higher than those of ad-enocarcinoma NOS(42.9％vs 23.0％,P=0.001;67.9％vs 46.2％,P=0.002).The incidence of mismatch repair defi-ciency in colorectal MPC was significantly lower than that in ade-nocarcinoma NOS(3.6％vs 13.8％,P=0.030).The hot spot mutation rate in exon 2,3 and 4 of KRAS gene in colorectal MPC was significantly higher than that in adenocarcinoma NOS(58.9％vs 42.2％,P=0.018),especially in KRAS G13D(17.9％vs 8.1％,P=0.019).The proportion of colorectal MPC components was not associated with clinicopathological and molecular features.There were no significant differences in clin-icopathological and molecular features between colorectal MPC and adenocarcinoma NOS with high-grade tumor budding.Con-clusion The clinicopathologic and molecular features of color-ectal MPC are different from those of adenocarcinoma NOS,and the diagnosis of this subtype may provide help for the formulation of treatment plan and the evaluation of prognosis.
万方数据
维普
