Colorectal cancer (CRC) is the third most common cancer worldwide, the second deadliest cancer in the United States. DNA methylation is a commonly used biomarker for non-invasive CRC detection in plasma. The low sensitivity of blood-based tests is due to several limitations of detecting ctDNA in early-stage cancer. We developed and validated a high-throughput methylation-based blood test highly sensitive for colorectal cancer and precancerous lesions. This previously established colorectal tumor-specific plasma ctDNA methylation markers (diagnostic model established by next-generation sequencing of 2181 gene loci methylation) had a high sensitivity in CRC patients and a high specificity in healthy individuals in a large retrospective sample study. This prospective, clinical study is to further evaluate the sensitivity of plasma ctDNA methylation haplotypes in detecting local residual or lymph node metastasis.
