ABSTRACT
@#Objective To explore the relation of preoperative red blood cell distribution width (RDW) with prognosis in esophageal cancer. Methods The PubMed, EMbase, Web of Science, Cochrane Library, VIP, Wanfang, CNKI and SinoMed databases were searched to identify potential studies assessing the correlation between preoperative RDW and prognosis of esophageal cancer patients from establishment of databases to February 2019. The endpoint events included the overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS). The Stata 12.0 software was applied for the meta-analysis and the hazard ratio (HR) and 95% confidence interval (CI) were calculated. Results A total of 10 retrospective studies involving 4 260 esophageal cancer patients from China or Japan were included. The score of Newcastle-Ottawa scale (NOS) of the included studies was more than 6 points. The results demonstrated that elevated preoperative RDW was significantly associated with poor CSS (HR=1.50, 95% CI 1.14 to 1.99, P=0.004) and DFS (HR=1.45, 95% CI 1.14 to 1.85, P=0.002), while no significant association between preoperative RDW and OS in esophageal cancer was observed (HR=1.17, 95% CI 0.95 to 1.45, P=0.143). Subgroup analysis based on the pathology revealed that preoperative RDW had high prognostic value in esophageal squamous carcinoma (ESCC) (HR=1.37, 95% CI 1.05 to 1.77, P=0.018). Conclusion Preoperative RDW may be an independent prognostic factor for Chinese and Japanese esophageal cancer patients, especially for ESCC patients. However, more prospective studies with bigger sample sizes from other countries are still needed to verify our findings.