RER+大肠癌的临床病理特点

目的探讨ＤＮＡ复制错误（ＲｅｐｌｉｃａｔｉｏｎｅｒｒｏｒＲＥＲ）与大肠癌（Ｃｏｌｏｒｅｃｔａｌｃａｒｃｉｎｏｍａ，ＣＲＣ）的关系。方法采用银染ＰＣＲ－ＳＳＣＰ方法，检测６１例大肠癌及其相应正常组织的第２、５、１７号染色体的４个位点的微小卫星ＤＮＡ不稳定性（Ｍｉｃｒｏｓａｔｅｌｌｉｔｅｉｎｓｔａｂｉｌｉｔｙ，ＭＳＩ），有两个位点的ＭＳＩ则诊断为ＲＥＲ＋。结果６１例大肠癌中，１８例为ＲＥＲ＋（２９５％）。ＭＲ阳性率在ＨＮＰＣＣ为７５％与散发性大肠癌的２３．９％比较（Ｐ＝０．０２５）有显著差异。ＲＥＲ十大肠癌大多为低分化大肠癌（Ｐ＜０．０００１），多位于右半结肠（Ｐ＜０．０５），有家族史，年龄小于３５岁，Ｄｕｃｋｅｓ分期Ａ．Ｂ期患者所占比例高。发现２例病理阴性者手术切缘组织ＲＥＲ＋。结论ＲＥＲ＋是ＨＮＰＣＣ常见的分子学事件。ＲＥＲ十肿瘤与ＲＥＲ．肿瘤有不同的生物学特性。ＲＥＲ＋可作为大肠癌手术切缘的分子标志。

Clinicopathological features of RER+ colorectal carcinoma

Objective To study the relationship between RER and colorectal carcinoma. Methods Silver stain PCR-SSCP method wasused to detect microsatellite instability(MSI) at 4 loci on chromosome 2,5,17 in 61parffin-embedded specimens of colorectalcarcinoma and their paired normal tissue. The tumor is diagnosed as RER+ if MSI is observed at 2 loci. Results RER+ tumor wasobserved in 18/61 cases, among which 4/7 cases were (with family history) and 3/4 were of hereditary nonpolyposis colorectal cancer(HNPCC). The ratio of RER+ patients in HNPCC was significantly higher than that among sporadic CRC(11/46, 23.9%). It waspredominantly a feature of pooly differentiated adenocarcinoma (P<0.0001), and had a tendency to involve the right side of thecolon and a higher proportion of family history, with the patients ape often younger than 35 years, and with pathological stages ofDuckes A, B. In addition, RER+ was observed at the tumor resection margin in 2 cases. Conclusion RER+ is a common molecularhereditary event in HNPCC. There are different clinicopathological features between RER+ CRC and RER-CRC and RER+ is a goodmolecular mark to indicate the tumor resection margin.