نبذة مختصرة : Background Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Early detection of CRC can significantly reduce its mortality rate. Current method of CRC diagnosis relies on the invasive endoscopy. Non-invasive assays including fecal occult blood testing (FOBT) and fecal immunological test (FIT) are compromised by low sensitivity and specificity, especially at early stages. Thus, a non-invasive and accurate approach for CRC screening would be highly desirable. Results A new qPCR-based assay combining the simultaneous detection of the DNA methylation status of ten candidate genes was used to examine plasma samples from 56 normal controls, 6 hyperplastic polys, 9 non-advanced adenomas (NAAs), 22 advanced adenomas (AAs) and 175 CRC patients, using 10 ng of cfDNA. We further built a logistic regression model for CRC diagnosis. We tested ten candidate methylation markers including twist1, vav3-as1, fbn1, c9orf50, sfmbt2, kcnq5, fam72c, itga4, kcnj12 and znf132. All markers showed moderate diagnostic performance with AUCs ranging from 0.726 to 0.815. Moreover, a 4-marker model, comprised of two previously reported markers (c9orf50 and twist1) and two novel ones (kcnj12 and znf132), demonstrated high performance for detecting colorectal cancer in an independent validation set ( N = 69) with an overall AUC of 0.911 [95% confidence interval (CI) 0.834–0.988], sensitivity of 0.800 [95% CI 0.667–0.933] and specificity of 0.971 [95% CI 0.914–1.000]. The stage-stratified sensitivity of the model was 0.455 [95% CI 0.227–0.682], 0.667 [95% CI 0.289–1.000], 0.800 [95% CI 0.449–1.000], 0.800 [95% CI 0.449–1.000] and 0.842 [95% CI 0.678–1.000] for advanced adenoma and CRC stage I-IV, respectively. Conclusion kcnj12 and znf132 are two novel methylation biomarkers for CRC diagnosis. The 4-marker methylation model provides a new non-invasive choice for CRC screening and interception.
Processing Request
No Comments.