遗传性非息肉病性结直肠癌的分子病理研究

目的研究遗传性非息肉病性结直肠癌的分子病理特征,评估该病在北京地区住院人群中的发病情况。方法 94例结直肠癌组织标本均采集自2012年3~9月于北京市中西医结合医院及解放军总医院住院接受手术治疗并经病理确诊为结直肠癌的患者。使用免疫组化方法对肿瘤组织内错配修复基因MLH1、MSH2、MSH6及PMS2的蛋白表达情况进行检测。结果 94例结直肠癌患者中,至少有一种错配修复基因表达为阴性的共有13例,其中MLH1表达为阴性的有3例,MSH2表达为阴性的有11例,MSH6表达为阴性的有2例,PMS2表达为阴性的仅有1例,遗传性非息肉病性结直肠癌的发病率为13.83%,MSH2基因突变所占比例达84.62%,与遗传性非息肉病性结直肠癌国际合作组织提供的数据（40%）相比,差异有统计学意义（P〈0.05）。结论北京地区住院的结直肠癌患者中,遗传性非息肉病性结直肠癌发病率高于世界每年新发病例的水平,且MSH2基因突变致病尤为突出。

Molecular pathological character of hereditary nonpolyposis colorectal cancer

Objective To study the molecule pathological characteristics of hereditary nonpolyposis colorectal cancer and to evaluate the morbidity of this disease among in-patients in Beijing. Methods 94 samples of colorectal cancer tissue were all collected from the patients who accepted operations in Beijing Hospital of Integrated Traditional and Western Medicine and the General Hospital of Chinese People＇s Liberation Army from March to September 2012, and afterward diagnosed as colorectal cancer by pathology. Immunohistochemistry was applied in detecting the protein expressions of mismatch repair gene MLH1, MSH2, MSH6 and PMS2 in the cancer samples. Results Among 94 colorectal cancer samples, 13 samples suggested negative expression of at least one mismatch repair gene, wherein 3 samples had negative MLH1 expression, 11 samples had negative MSH2 expression, 2 samples had negative MSH6 expression, and only one sample had negative PMS2 expression. Hereditary nonpolyposis colorectal cancer had a morbidity of 13.83%.The percentage of MSH2 mutation reached 84.62%, which showed a statistical difference to the data（40%） provided by the International Collaborative Group on hereditary nonpolyposis colorectal cancer（P〈0.05）. Conclusion Among colorectal cancer in-patients in Beijing, hereditary nonpolyposis colorectal cancer has a higher morbidity than the average level of annual new cases in world, especially out of MSH2 gene mutations.