Fig. 2From: An update of clinical value of circulating tumor DNA in esophageal cancer: a systematic review and meta-analysisHazard ratio (HR) for overall survival (OS) of the included studies. A: subgroup-analysis based on pathology, EAC: esophageal adenocarcinoma; ESCC: esophageal squamous cell carcinoma; B: subgroup-analysis based on method, NGS: next-generation sequencing (NGS); ddPCR: droplet digital polymerase chain reactionBack to article page