【摘要】 目的 了解大肠癌微卫星不稳定性(microsatelliteinstability, MI)情况。方法 用6个微卫星位点检测PCR扩增所选位点PCR产物用8%变性聚丙烯酰胺凝胶电泳、银染。结果 60例大肠癌中，20例表现MI，其中11例为复制错误(replicationerrors, RER)阳性。RER阳性与RER阴性大肠癌患者相比，发病年龄较年轻，一级亲属有恶性肿瘤病史者明显高于RER阴性，倾向位于结肠，呈浸润性生长，Ⅲ～Ⅳ期比例高。5例大肠癌伴大肠腺瘤病例中，4例腺瘤有MI。结论 中国人大肠癌MI发生率介于文献报道之间，MI为大肠癌形成过程中的早期分子事件，RER为肿瘤易感指标之一。

Study of microsatelliteinstability of colotectal cancer and its clinical significance

XIONG Bin, ZHENG Shu, CAI Xinhan.

    Cancer Institute, Zhejiang Medical University, Hangzhou 310009

【Abstract】 Objective Toevaluate microsatellite instability (MI) of colorectal cancerin China. Method Replication error (RER) status was examined by using 6 microsatellite loci D2S123, D2S119,D13S160, D8S282, D3S1293 and D18S58. The loci were amplified by PCR technique. The PCRproducts were separated on denatured polyacrylamide gel and then silver stained. Results Ofthe 60 cases of colorectal cancer studied, 20 (33.3%) showed MI, 11 cases (18.3%) were RERpositive. In 11 RER-positive cases, 4(36.4%) had family history of malignant tumor, whileonly 8.2% had positive family history in RER-negative cases (P<0.05). The RER-positivepatients were younger, and their cancer occurred more frequently in the colon withinvasive type of growth. There were more cancers in Dukes III and IV in the RER-positivepatients. In 5 colorectal cancer cases associated with adenoma, MI was detectable in 4adenomas. Conclusion MI phenotype might be present ubiquitously insporadic colorectal cancers in China. Its frequency is comparable to that of otherreports. MI is a relatively early molecular event in the genesis of colorectal cancers.RER is a useful sign of susceptibility to the development of colorectal cancer.

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