Highly sensitive fecal DNA testing of NDRG4 12b methylation is a promising marker for detection of colorectal precancerosis.

ABSTRACT

PURPOSE: The purpose of this study was to research and validate techniques for extracting DNA from human genomes, explore the sensitivity and specificity of known nucleic acid markers of intestinal malignancy in Chinese patients with early colorectal cancer. We also tried to find adenoma-specific biomarkers in human DNA in feces. METHODS: We compared the ability of fecal DNA testing, Fecal Occult Blood Testing (FOBT) and serum tumor markers to diagnose different types of polyps, and DNA testing was significantly superior to the other two methods. We also found a dominant expression of NDRG12b methylation in multi-target DNA testing, which may be a promising marker for detection of colorectal precancerosis. RESULTS: The sensitivity of NDRG4 12b methylation was 85.7% for advanced adenomatous polyp (AP), and 62.6% for non-advanced AP, respectively, with specificity of 70.8%. The diagnostic efficacy of NDRG4 12b methylation for detecting advanced AP was significantly higher than FOBT (sesitivity 85.7% vs. 42.9%, p<0.05). The receiver operating characteristics (ROC) curve for NDRG4 12b methylation in detecting AP showed a relatively high area under the curve (AUC = 0.807). CONCLUSIONS: Our results indicate that highly sensitive fecal DNA testing of NDRG4 12b methylation is a promising marker for detection of colorectal precancerosis, especially in detecting adenomatous polyp.