具有家族背景大肠癌微卫星不稳定性研究

Study on Microsatellite Instability in Colorectal Cancer Patients with Familial Predisposition

目的探讨微卫星不稳定性(MSI)在具有家族背景的大肠癌和散发性大肠癌中的发生及其与临床病理参数之间的关系。方法采用聚合酶链反应—单链构象多态性(PCR-SSCP)结合银染显色技术,通过位于5条染色体上的5个不同的微卫星位点,对29例具有家族背景的大肠癌及30例散发性大肠癌病例进行MSI检测。结果有家族背景大肠癌中MSI阳性率(MSI-H)为48.28%(14/29),与散发性大肠癌MSI阳性率的13.3%(4/30)相比,差异显著(P<0.05)。各位点在两组中的检出率不同,其顺序为BAT-26>D2S123>D5S346>BAT-25>D17S250。微卫星不稳定性阳性病例与阴性相比,其临床病理特点为右半结肠癌多、年轻病人中发生率高,而在性别、大小、组织分化程度、有无转移、浸润深度方面无明显差别。结论MSI在具有家族背景的大肠癌中阳性率明显高于散发性大肠癌,MSI阳性的大肠癌具有某些临床病理特点。

Objective To investigate the microsatellite instability （MSI） in colorectal cancer patients （CRC） with famihal predisposition and in sporadic colorectal cancer patients and compare the MSI status of CRC with its clinicopathological parameters. Methods 5 microsatellite loci from 5 different chromosomes were detected hy polymerase chain reaction single strand conformation polymorphism （PCR-SSCP） and silver-staining methods. MSI was measured in 29 cases of CRC with familial predisposition and in 30 cases of sporadic CRC. Resuits The positive rate of MSI in CRC with familial predisposition was 48.28% （14/29）,which was higher than that in sporadic CRC 13.30% （4/30） with statistic significance（P 〈 0.05）. Different sensitivities of MSI were shown at five loci. It was the most sensitive at BAT- 26, then at D2S123, D5S346, BAT-25 and the least sensitive at D17S250. Compared with the MSI-negative cases, the MSI-positive cases had close relationship with early age of cancer onset and the proclivity for proximal colon （P 〈 0.05）. No association was detected between MSI status and the factors of sex, tumor size,invasive depth and lymph node metastases. Conclusion The positive rate of MSI was higher in CRC with familiar predisposition than in sporadic CRC. MSI has close relationship with some clinicopathological parameters .