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 (ĸ = 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.