几种粪便脱落细胞检查方法的大肠癌筛检效率比较

A comparative study on various methods of fecal exfoliated cell testing for screening of colorectal cancer

目的评价不同粪便脱落细胞检查方法的大肠癌筛检效率。方法对814例结肠镜检查者分别经清肠液法、二次自然粪便法、磁选法、自然排便联合清肠液液基法提取粪便脱落细胞，进行细胞学诊断。部分经清肠液法受检者提取细胞后行DNA核定量分析（清肠液＋DNA核定量分析法）。部分二次自然粪便法提取的粪便行基因检测。二次自然粪便法和自然排便联合清肠液液基法提取的粪便同时进行粪隐血检测。结果粪便脱落细胞检出大肠癌的敏感性为66．27％（112／169），特异性为99．56％（225／226）。大肠癌患者粪便中提取异型细胞的阳性率与大肠癌分化程度和Duke分期无关（P〉0．05）。二次自然排便法、自然排便联合清肠液液基法、清肠液＋DNA核定量分析法筛检大肠癌的敏感性（分别为76．09％、68．29％、76．92％）优于单纯清肠液法和磁选法（分别为26．31％、43．24％）。粪便脱落细胞p53、K-ras、腺瘤性息肉病（APC）基因检测阳性率与癌组织相应基因检测的一致率为83．33％（25／30）、9／10、9／10。基因检测的阳性率低于粪便脱落细胞学检测。联合进行粪隐血和粪脱落细胞学检测检出大肠癌的敏感性（93．10％）高于单独进行粪隐血试验（80．46％）和粪便脱落细胞学检测（73．56％）。结论粪便脱落细胞学检查是大肠癌筛检的有效手段，利用液基薄层技术对患者自然排便或清肠液进行两次筛查并联合粪隐血检测是最佳筛检方案。

Objective To evaluate the effect of various methods of fecal exfoliated cell testing for screening of colorectal cancer. Methods The stool samples from 814 patients who underwent colonoscopy were collected for fecal exfoliated cell testing using diarrhea feces, twice naturally evacuated feces, magnetic separation or naturally evacuated combined with diarrhea feces. The fecal exfoliated cells were isolated and examined cytologically. The DNA quantitative analysis and gene detection were carried out. Fecal occult blood test was simultaneously performed in twice naturally evacuated feces and naturally evacuated combined with diarrhea feces. Results The sensitivity and specificity of exfoliated cells testing for colorectal cancer was 66.27% （112 of 169 cases of colorectal cancer）and 99.56% （225 of 226 normal subjects）, respectively. There was no correlation of positive rate with differentiations of colorectal cells or Duke＇s stages （P〉 0. 05 ）. The nuclear DNA quantitative analysis showed that the sensitivity for detecting cancer was 76. 09% for twice naturally evacuated feces and 68. 29% for naturally evacuated combined with diarrhea feces,which was superior than diarrhea feces （26.31%） and magnetic separation （43.24 %）. The positive rate of genes detected in carcinoma tissues concordant with fecal exfoliated cells testing were 83.33% （25/30） for p53, 9/10 for APC and 9/10 for K-ras. The sensitivity of cytology was higher than gcnc detection. The sensitivity of cancer detection was higher in combining exfoliated cells test with fecal occult blood test （93. 10%） than exfoliated cells test （73. 560/00） or fecal occult blood test （80.46%） alonc（P〈0.05）. Conclusions Fecal exfoliated cells test is an effective method for screening of colorectal cancer. It is the best option for detecting cancer by twice tests of fecal exfoliated cells with liquid-based thin layer cytological test, and combined with fecal occult blood test.