The SEPT9 gene methylation assay is capable of detecting colorectal adenoma in opportunistic screening

Aim: This study validated the detection of colorectal adenoma in opportunistic screening using the SEPT9 gene methylation assay. Materials & methods: Plasma samples including 85 colorectal cancers, 364 adenomas, 216 hyperplastic polyps, 372 other gastrointestinal diseases and 324 normal subjects, were obtained and tested using the Epi proColon 2.0 CE assay. Results & conclusion: The SEPT9 assay detected 38.7% of all types of adenoma, including 27.8% of serrated adenoma, 28.7% of tubular adenoma, 53.7% of tubulovillous adenoma and 83.3% of villous adenoma. It also detected 27.5% of nonadvanced adenoma (NAA), 47.0% of advanced adenoma (AA) without high-grade dysplasia and 62.5% of AA with high-grade dysplasia. The average adenoma detection rate was 31.8% (95% CI: 28.3-35.4%) with the Boston Bowel Preparation Scale score at 7.6 +/- 1.2 (mean +/- SD). Our study provided strong evidence for the application of the SEPT9 assay in AA detection in opportunistic screening.