en 23407878 Cell free DNA (cfDNA) is a genetic biomarker that is present in serum or plasma in high concentration in many types of cancer. Identification of circu-lating cancer related DNA molecules in serum or plasma is a non-invasive tool for early diagnosis and prognosis in many cancer patients. For this review, study selection and data extraction were performed by the authors. Detection of point mutations, microsatellite alterations, DNA hypermethylations and losses of heterozygosity in circulating cell free DNA have been characterized in esophagus cancer. Application of circulating cell free DNA as a biomarker, provide the best opportunity for constructing non-invasive tests for early de-tection, prognosis and management of cancer patients, after therapy in many types of cancer. Biomarkers, Early detection, Esophagus neoplasm, Prognosis 3 13 https://www.ajmb.org/En/Article.aspx?id=76 https://www.ajmb.org/PDF/En/FullText/76.pdf SaeidGhorbianDepartment of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran285AliM. ArdekaniReproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran2