The value of methylated circulating tumor DNA as biomarkers in cancer diagnosis and prognosis

Circulating tumor DNA (ctDNA) in the blood of cancer patients provides an opportunity for non-invasive sampling of tumor DNA. This liquid biopsy allows for detection of copy number variations, tumor-specific mutations, epigenetic changes, and can be used to guide and improve treatment throughout real-time tracking the course of tumor disease. Aberrant methylation of specific gene regions can be a very consistent feature of cancer, in contrast to mutations, which makes ctDNA methylation amenable to the design of widely clinical applications in early diagnosis, monitoring disease status, predicting treatment response and predicting prognosis. Therefore, ctDNA methylation detection is considered as one of the most valuable methods for cancer diagnosis and risk assessment. Key words: Neoplasms; Circulating tumor DNA; DNA methylation; Prognosis