Accuracy of early detection of colorectal tumours by stool methylation markers:A meta-analysis

AIM:To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours.METHODS:Electronic databases including PubMed,Web of Science,Chinese Journals Full-Text Database and Wanfang Journals Full-Text Database were searched to find relevant original articles about methylated genes to be used in diagnosing colorectal tumours. A quality assessment of diagnostic accuracy studies tool(QADAS) was used to evaluate the quality of the included articles,and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis.RESULTS:Thirty-seven articles met the inclusion criteria,and 4484 patients were included. The sensitivity and specificity for the detection of colorectal cancer(CRC) were 73%(95%CI:71%-75%) and 92%(95%CI:90%-93%),respectively. For adenoma,the sensitivity and specificity were 51%(95%CI:47%-54%) and 92%(95%CI:90%-93%),respectively. Pooled diagnostic performance of SFRP2 methylation for CRC provided the following results:the sensitivity was 79%(95%CI:75%-82%),the specificity was 93%(95%CI:90%-96%),the diagnostic OR was 47.57(95%CI:20.08-112.72),the area under the curve was 0.9565. Additionally,the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows:sensitivity was 43%(95%CI:38%-49%),specificity was 94%(95%CI:91%-97%),the diagnostic OR was 11.06(95%CI:5.77-21.18),and the area under the curve was 0.9563.CONCLUSION:Stool-based DNA testing may be useful for noninvasively diagnosing colorectal tumours and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis.