How to Cite
Abstract
BACKGROUND: Recent studies have shown that aberrant methylation of Syndecan-2 (SDC2) can be detected in stool samples from patients with colorectal cancer (CRC) and advanced adenoma (AA). This study aims to evaluate both the effectiveness and accuracy of a stool DNA (sDNA) test of methylated SDC2 in detecting CRC and AA in comparison to a fecal immunochemistry test (FIT) and plasma carcinoembryonic antigen (CEA). METHODS: The study enrolled 120 participants who were either diagnosed with CRC and AA or were CRC- or AA-negative according to colonoscopy. Stool samples for each participant were collected and subjected to both FIT and the sDNA test for SDC2 methylation. Meanwhile, peripheral blood was drawn to assess plasma CEA level. Analytical performance of these three detection methods was compared in terms of sensitivity and specificity. Furthermore, Spearman correlation was performed to evaluate possible correlation between SDC2 methylation and clinical characteristics in CRC patients. RESULTS: The sensitivity of the sDNA test in detecting CRC was 90.7%, significantly higher than both FIT (58.1%) and plasma CEA (20.9%). The detection rate of the sDNA test for AA was also respectable at 52.7%, dramatically better than FIT (9.1%) and plasma CEA (3.6%). The sDNA test was also particularly robust for stage I/II CRC at 87% sensitivity. Moreover, it could detect a significant number of colonic carcinomas in situ as well as high-grade intraepithelial neoplasia, besting FIT and CEA by a large margin (11/13 vs. 3/13 vs. 1/13). For both SDC2 testing and FIT, the specificity was 86.4%, lower than the 90.9% specificity observed for plasma CEA. Interestingly, we found that SDC2 methylation status was positively correlated with tumor location, TNM staging, and size, but inversely correlated with age at diagnosis. CONCLUSIONS: Single-target SDC2 methylation testing is a more sensitive detection strategy for CRC and AA than conventional approaches such as FIT and plasma CEA in China