粪便中检测K-ras基因突变对老年大肠癌诊断价值的研究

STUDY ON DIAGNOSTIC VALUE OF DETECTING K-ras GENE MUTATION IN STOOL FOR LARGE INTESTINAL CANCER IN THE ELDERLY

探讨粪便K ras基因检测在老年大肠癌临床诊断中的价值。收集连续就诊的 2 3例老年大肠癌患者、2 0例结肠腺瘤性息肉患者及 2 0名健康老年查体者的粪便 ,并从中提取DNA ,应用等位基因特异性杂交技术检测粪便K ras基因第 12位密码子第 1、2位碱基突变情况。结果K ras基因突变率在大肠癌患者为 5 6 5 2 % (13/ 2 3) ,明显高于正常查体者的 5 % (1/ 2 0 ) (P <0 0 1) ,与结肠腺瘤性息肉组的 30 % (6 / 2 0 )比较 ,差异无显著性意义 (P >0 0 5 )。 92 31% (12 / 13)的大肠癌K ras基因突变位点发生在第 12位密码子第 2位碱基。研究表明 ,结肠癌患者组织及粪便中K ras基因突变的检出具有良好的一致性 ,提示粪便中检测K

To study the significance of detection of K ras mutation in stool samples in the diagnosis of large intestinal cancer, stool and local tissue samples were collected from consecutively diagnosed patients, among them 23 cases suffered from large intestinal cancer, 20 cases from colorectal adenomatoid polyps and 20 healthy subjects. DNA was extracted from both the stool and the tissue, K ras gene mutations at the first and second base of codon 12 were studied by allele specific mismatch method in both of them. The results showed that K ras mutation rate in large intestinal cancer was 56 52%(13/23), which was much higher than 5%(1/20)in healthy subjects( P <0 01). The rate of large intestinal cancer group was not different significantly from that of the colorectal ademomatoid polyp group(30%,6/20)( P >0 05). There was a 92 31%(12/13)incidence of K ras mutation at the second base of codon 12 in large intestinal cancer. The results of detecting the K ras mutation were highly identical in both the stool and the tissue ( P <0 01). Our results indicate that detecting K ras mutations in stool samples provides a non invasive method in diagnosing large intestinal cancer of the elderly .