Villa E, Dugani A, Rebecchi A M, Vignoli A, Grottola A, Buttafoco P, Losi L, Perini M, Trande P, Merighi A, Lerose R, Manenti F
Department of Internal Medicine, University of Modena, Italy. Ericavil@unimail
Gastroenterology. 1996 May;110(5):1346-53. doi: 10.1053/gast.1996.v110.pm8613038.
BACKGROUND & AIMS: The gold standard for screening for colorectal carcinoma is colonoscopy. The aim of this study was to compare endoscopic results with those obtained using the noninvasive screening test of K-ras determination in the stool in a large population of patients undergoing colonoscopy.
Two hundred thirty consecutive patients were studied by K-ras amplification on stool-derived DNA using polymerase chain reaction and oligomer-specific hybridization.
Wild-type K-ras was amplified in 103 of 230 patients (44.8%), the rate of amplification being directly proportional to the presence of an organic disease of the intestine characterized by hyperproliferating mucosa. In 30 of these 103 patients (29.1%), a K-ras mutation was found. Four of 5 with early colorectal carcinoma, all who had K-ras mutations in the tumor, were identified. In first-degree relatives of patients with colorectal carcinoma, all subjects either carrying adenomas > 1 cm in diameter or multiple smaller adenomas were identified. In patients with inflammatory bowel disease, the test identified the only patient with neoplastic transformation.
The sensitivity and specificity of K-ras determination on stool-derived DNA in patients with colorectal carcinoma, in first-degree relatives of patients with colorectal carcinoma, and in patients with inflammatory bowel disease support the opportunity of a large-scale trial to validate its use as a screening test.
结直肠癌筛查的金标准是结肠镜检查。本研究的目的是在大量接受结肠镜检查的患者中，比较内镜检查结果与使用粪便中K-ras测定的非侵入性筛查试验所获得的结果。
对连续230例患者的粪便DNA进行聚合酶链反应和寡核苷酸特异性杂交，以检测K-ras扩增情况。
230例患者中有103例（44.8%）扩增出野生型K-ras，扩增率与以黏膜增生为特征的肠道器质性疾病的存在直接相关。在这103例患者中有30例（29.1%）发现K-ras突变。5例早期结直肠癌患者中有4例被识别出来，这4例患者肿瘤均有K-ras突变。在结直肠癌患者的一级亲属中，所有携带直径>1 cm腺瘤或多个较小腺瘤的受试者均被识别出来。在炎症性肠病患者中，该检测识别出唯一发生肿瘤转化的患者。
在结直肠癌患者、结直肠癌患者的一级亲属以及炎症性肠病患者中，对粪便DNA进行K-ras测定的敏感性和特异性支持开展大规模试验以验证其作为筛查试验的可行性。
