Comparison of a Prototype Reverse Hybridization Assay and MethyLight for Detection of SFRP2 Promotor Methylation in Fecal DNA
Background This study aimed to evaluate the diagnostic performance of a novel nonquantitative methylation-specific reverse hybridization (MSRH) assay to detect secreted frizzled-related protein 2 ( SFRP2) promotor methylation in fecal DNA. Methods SFRP2 promoter methylation was investigated in stool DNA isolated from 18 colorectal cancer (CRC) patients and 22 healthy controls using the MSRH assay based on methylation-specific DNA amplification followed by reverse hybridization of biotinylated amplicons to sequence-specific methylation detection probes, with MethyLight serving as a reference method. Results SFRP2 promotor methylation as determined by MSRH vs. MethyLight showed a sensitivity and specificity of 61.1% and 86.3% vs. 77.7% and 77.3%, respectively. Moderate agreement (κ = 0.54, 95% confidence interval [95% CI], 0.29-0.80, p<0.001) was observed between the 2 methods. However, the differences in SFRP2 promotor methylation observed between CRC patients and healthy individuals by both assays were statistically significant (p<0.001). Conclusions Our findings, although limited by the small sample size, do not support the use of the MSRH assay for CRC screening in stool.