结直肠癌、结直肠腺瘤微卫星不稳定性检测及其临床意义

目的 探讨微卫星不稳定性（ＭＳＩ）在结直肠癌发生中的意义及其与结直肠癌细胞增殖活性和预后的关系,方法 采用聚合酶链反应－简单序列长度多态性（ＰＣＲ－ＳＳＬＰ）及免疫组化ＳＰ方法,对５６例结直肠癌,９例腺瘤及６例腺瘤癌变的ＭＳＩ和增殖细胞核抗原（ＰＣＮＡ）表达进行了检测。结果 显示结直肠癌ＭＳＩ总阳性率为４４．６４％（２５／５６例）,共中遗传性非息肉病性结直肠癌３／４例阳性,散发性结直肠癌２２／５２

The detection of microsatellite instability in carcinoma and adenoma of large bowel and its significance

Objective To explore the role of microsatellite instability (MSI) in colorectal carcinogenesis and the relationship between MSI, proliferation activity and prognosis. Methods PCR SSLP and immunohistochemistry methods were used to detect MSI and the expression of PCNA in 56 cases of carcinomas, 9 cases of adenomas and 6 cases of adenomas with malignant changes. Results The total positive rate of MSI were 25/56 cases in colorectal carcinomas. The MSI positive cases were 3/4 in HNPCCs, 22/52 in sporadic colorectal carcinomas, 2/9 in adenomas and 2/6 in adenoma with malignant changes respectively. The PCNA labelling index of MSI positive tumors were significantly lower than that of MSI negative tumors ( P <0.01). The 3 and 5 year survival rates in patients with MSI positive colorectal carcinomas were higher than those of MSI negative tumors. Conclusion MSI may be an early molecular alteration and another molecular mechanism in colorectal carcinogenesis. The MSI positive tumors have low proliferating activity and a better clinical outcome. The detection of MSI might be useful in predicting prognosis of colorectal carcinomas.