Diagnostic value of multi-gene methylation in colorectal cancer screening

Objective: To evaluate the diagnostic value and clinical application of multi-gene methylation assay in colorectal cancer (CRC) screening. Methods: This was a single-center, retrospective, real-world study conducted at the First Affiliated Hospital of Shantou University Medical College, China. A total of 450 participants were enrolled from January 2023 to December 2024, including 150 healthy individuals, 120 colorectal polyp patients, and 180 CRC patients. The methylation status of six plasma-derived loci (SEPT9-R1, SEPT9-R2, BCAT1, IKZF1, BCAN, and VAV3) was assessed using real-time multiplex quantitative PCR (qPCR). The diagnostic performance and predictive factors of the multi-gene methylation assay for CRC detection were assessed. Results: The multi-gene methylation assay effectively differentiated healthy controls, colorectal polyp patients, and CRC patients (P < 0.001), and methylation levels increased with advancing tumor stage. The combined panel demonstrated superior diagnostic accuracy over single-gene assays, yielding an AUC of 0.958 (95% CI: 0.934-0.982) in the training cohort and 0.952 (95% CI: 0.920-0.984) in the validation cohort. Multivariate analysis further identified tumor size (OR = 1.974, 95% CI: 1.321-2.950, P = 0.005) and TNM stage (OR = 2.117, 95% CI: 1.452-3.087, P = 0.002) as independent predictors of multi-gene methylation positivity. Conclusion: Multi-gene methylation detection showed high diagnostic value for CRC and may serve as a valuable adjunct tool in CRC screening strategies.