联合检测粪便中多基因突变进行大肠癌二级筛查的研究

Detection of Multiple Gene Mutations in Stool for Secondary Screening for Colorectal Cancer

目的通过研究p53、K-ras及APC在大肠癌组织及粪便中的突变情况,探讨粪便多基因联合检测进行大肠癌二级筛查的可行性。方法应用聚合酶链反应-单链构象多态性(PCR-SSCP)分析及硝酸银染色法,检测40例大肠癌患者的肿瘤组织与粪便及40例正常人肠黏膜组织与粪便中p53、K-ras及APC3种基因的突变情况,并比较多个基因联合检测与单基因检测基因突变率的灵敏性之间的差异。结果①40例大肠癌组织中p53、K-ras及APC基因突变率分别为57.50%、50.00%及60.00%,粪便中相应的基因突变率分别为42.86%、40.00%及51.43%,粪便基因突变与组织中相应基因突变的符合率分别为65.22%、70.00%及75.00%。40例正常肠黏膜组织及粪便中3种基因均未检出突变;②3种基因联合检测的突变率明显高于单基因检测(P<0.05);③粪便基因联合检测与粪便隐血试验比较,灵敏性之间差异无统计学意义,但前者的特异性明显高于后者(P<0.05)。结论粪便基因联合检测诊断大肠癌的灵敏性及特异性均较高,有望作为一种无创、特异、有效的筛查手段,与粪便隐血试验结合序贯进行大肠癌的筛查。

Objective To evaluate the possibility of detection mutations of multiple genes in stool for secondary screening for colorectal cancer. Methods Tumor specimens and stool samples from 40 patients with colorectal cancer and 40 normal persons were examined for mutations of p53, K-ras and APC gene by polymerase chain reaction single strand conformation polymorphism （PCR-SSCP） and silver nitrate staining. Results ①The mutation rate of p53, K-ras and APC gene in the tissues and stools of colorectal cancer respectively were 57. 50%, 50. 00%, 60.00% and 42.86%, 40.00%, 51.43%, and no mutations were found in normal mucosa and stool. ②The mutation ratioes between multiple gene and single gene had significant difference （P〈0.05）. ③The sensitivities had no significant difference between faecal occult blood test （FOBT） and multiple gene mutations detection in the diagnosis of colorectal cancer, but the specificity of the latter was higher than FOBT （P〈0.05）. Conclusion Detection of multiple gene mutations in stool is a vauble method in the secondary screening for colorectal cancer.