粪便Vimentin和SFRP2甲基化在结直肠癌筛查中的作用

Value of the methylation status of Vimentin and SFRP2 in feces for colorectal cancer screening

目的探讨粪便中Vimentin和SFRP2甲基化状态在结直肠癌筛查中的价值。方法收集患者合格的粪便标本69例,其中结直肠癌23例、进展期腺瘤24例和健康人群22名,采用甲基化特异性PCR技术分析Vimentin和SFRP2甲基化状态,并与单个基因甲基化和粪便免疫隐血试验(FIT)的检测性能相比较,评价其在结直肠癌筛查中的灵敏度和特异度。结果结直肠癌组中单个Vimentin和SFRP2甲基化检出率分别为82.6%和69.6%,进展期腺瘤组为62.5%和41.7%,正常对照组为13.6%和13.6%。Vimentin和SFRP2联合检测在结直肠癌组的灵敏度为87.0%,高于FIT的56.5%(χ~2=5.25,P<0.05),与单基因检测比较,差异无统计学意义(P>0.05)。进展期腺瘤组中,联合检测的灵敏度为70.8%,高于SFRP2的41.7%(χ~2=4.15,P<0.05)和FIT的29.2%(χ~2=8.33,P<0.01),与Vimentin检测比较差异无统计学意义(P>0.05)。正常对照组联合检测的特异度为86.4%,与单基因检测相同,与FIT(72.7%)比较,差异无统计学意义(P>0.05)。联合检测在管状腺瘤中检出率为92.3%,高于SFRP2的53.8%(χ~2=4.9,P<0.05),与Vimentin(76.9%)比较,差异无统计学意义(P>0.05),在绒毛状管状腺瘤和管状腺瘤/绒毛状管状腺瘤中检出率与Vimentin相同,与SFRP2比较,差异无统计学意义(P>0.05)。联合检测在伴有上皮内瘤变中的检出率与单基因检测差异均无统计学意义(P>0.05)。结论粪便中联合Vimentin和SFRP2检测优于单基因及FIT检测,在结直肠癌筛查中具有潜在的应用价值。

Objective To evaluate the methylation status of Vimentin and SFRP2 in feces for colorectal cancer screening. Methods Qualified feces samples were collected from 69 patients, including 23 cases of colorectal cancer, 24 cases of advanced adenoma and 22 healthy people. The promoter methylation of fecal Vimentin and SFRP2 genes was detected by methylation-specific PCR and compared with single gene methylation and the fecal immunochemical test(FIT) to evaluate its sensitivity and specificity. Results The detection rates of single Vimentin and SFRP2 methylation were 82.6% and 69.6%, respectively, in the colorectal cancer group, 62.5% and 41.7% in the advanced adenoma group, and 13.6% and 13.6% in the normal control group. The sensitivity of the combined detection of Vimentin and SFRP2 in the colorectal cancer group was 87.0%, higher than that of FIT(56.5%, χ~2=5.25, P<0.05), which showed no statistical difference compared with the single-gene test(P>0.05). In the advanced adenoma group, the sensitivity of combined detection was 70.8%, which was higher than that of SFRP2(41.7%, χ~2=4.15, P<0.05) and FIT(29.2%, χ~2=8.33, P<0.01). There was no statistical difference compared with Vimentin test(P>0.05). The combined test specificity of the healthy group was 86.4%, the same as that of the single gene test, and there was no statistical difference compared with FIT(72.7%)(P>0.05). The detection rate of combined detection in tubular adenoma was 92.3%, higher than 53.8% of SFRP2(χ~2=4.9, P<0.05), and there was no statistical difference compared with 76.9% of Vimentin. The detection rate of villous tubular adenoma and tubular adenoma/villous tubular adenoma was the same as that of Vimentin, but there was no statistical difference compared with SFRP2(P>0.05). There was no statistical difference in the detection rate of intraepithelial neoplasia associated with combined detection and single gene detection(P>0.05). Conclusion The combined detection test of methylation of Vimentin and SFRP2 in feces is superior to single gene test and FIT, which has potential application value in colorectal cancer screening.