散发性结直肠癌中微卫星不稳定研究及其临床病理意义

目的检测散发性结直肠癌(SCRC)中的微卫星不稳定状态,并探讨其与临床病理特征的关系。方法应用荧光标记多重PCR法扩增微卫星位点BAT-25和BAT-26,将PCR扩增产物在荧光毛细管中进行电泳,以GenScan3.1软件扫描分析两个微卫星位点状况。结果112例SCRC患者中,BAT-25和BAT-26两个位点均阳性者14例,MSI-H发生率为12.5(14/112);BAT-25单位点阳性者4例,BAT-26单位点阳性者6例;两个位点均阴性者88例,MSS发生率为78.6。SCRC中MSI-H和MSS两组的比较显示:MSI-H者发病部位以近端结肠癌多见(P=0.034),组织学类型以黏液腺癌、印戒细胞癌相对多见(P=0.023),分化程度以低分化癌多见(P=0.039),而MSI-H与MSS两者在性别、年龄、肿瘤浸润深度、淋巴结转移、远处转移等方面差异无统计学意义。结论SCRC中微卫星不稳定是一个常见的分子事件,微卫星不稳定的SCRC好发于右半结肠,具有低分化的倾向。

Association of microsatellite instability with clinicopathological features of sporadic colorectal cancer

Objective To investigate the incidence of microsatellite instability(MSI) in sporadic colorectal carcinoma(SCRC) and its association with clinicopathological features.Methods Microsatellite analysis was performed on tissue samples from 112 cases of sporadic colorectal cancer.Microsatellite alterations of BAT-25 and BAT-26 were detected using fluorescent PCR followed by fragment analysis by automatic DNA sequencer with GeneScan 3.1 software.Results The rate of the high microsatellite instability among sporadic colorectal cancer patients was 12.5%,and the rate of the microsatellite stability was 78.6%.The microsatellite instability phenotype was correlated with the tumor site and the histopathologic type and the differentiation grade(P<0.05),while it was independent to the gender,age,tumor invasion,lymph node metastasis and distance metastasis.Conclusion MSI is a frequent molecular event in sporadic colorectal cancers,sporadic colorectal cancers with microsatellite instability may be prone to occur in the right colon and poorly differentiated adenocarcinomas.