非转移性结直肠癌组织中MMR的表达状态及意义

摘要

Objective To investigate the expression and significance of mismatch repair gene (MMR) in non-metastatic colorectal tissues.Methods Totally 141 patients with non-metastatic colorectal cancer who underwent surgery were selected,and none of them received preoperative radiotherapy or chemotherapy.The expression of four MMR proteins (MLH1,MSH2,MSH6,PMS2) in postoperative pathological specimens were detected by routine pathological examination and immunohistochemistry.One or more of the four proteins were not expressed,namely,the MMR expression was deleted (dMMR),and the clinicopathological features of the patients with normal and dMMR colorectal cancer were compared.Results The deletion rates of MLH1,MSH2,MSH6 and PMS2 were 15.6％ (22/141),2.8％ (4/141),7.1％ (10/141),15.6％ (22/141),and the dMMR rate was 25.5％ (36/141) in patients with non-metastatic colorectal cancer.MMR expression was correlated with non-metastatic colorectal cancer patient's age,location,tumor size and pathological type (all P ＜ 0.05),and dMMR occurred more frequently in patients younger than 60 years,proximal,mucinous and large tumors (all P ＜ 0.05).Conclusion MMR expression is absent in non-metastatic colorectal cancer,and MMR status is helpful in predicting prognosis and guiding therapy.%目的 观察错配修复基因(MMR)在非转移性结直肠组织中的表达状态并探讨其意义.方法 选取141例接受手术治疗的非转移性结直肠癌患者,均未接受术前放疗或化疗.术后病理标本进行常规病理检测及免疫组化法检测4种MMR蛋白(MLH1、MSH2、MSH6、PMS2)表达.四种蛋白中一种及以上不表达,即判定为MMR表达缺失(dMMR),对比MMR正常和dMMR结直肠癌患者的临床病理特征.结果 非转移性结直肠癌患者的MLH1、MSH2、MSH6、PMS2表达缺失率分别为15.6％ (22/141)、2.8％ (4/141)、7.1％(10/141)、15.6％ (22/141),dMMR率为25.5％ (36/141).MMR表达与非转移性结直肠癌患者年龄、部位、肿瘤大小及病理类型等有关(P均＜0.05),dMMR更多发生于60岁以下、近端部位、黏液类型癌及较大的肿瘤(P均＜0.05).结论 非转移性结直肠癌患者癌组织中MMR表达存在缺失,MMR状态的评估有助于判断患者预后和指导治疗.