High-dose versus standard-dose radiotherapy in concurrent chemoradiotherapy for inoperable esophageal cancer: A systematic review and meta-analysis

The aim of this study was to evaluate the effectiveness and safety of high-dose (HD-RT) versus standard-dose radiotherapy (SD-RT) in concurrent chemoradiotherapy (CCRT) for inoperable esophageal cancer (EC) patients.A systematic search of the literature was conducted by screening PubMed, Web of Science, EMBASE and Cochrane Library databases before October 7, 2022 to collect controlled clinical studies of high-dose (≥60 Gy) and standard-dose (50-50.4 Gy) radiation in CCRT for EC. For statistical analysis, a fixed-effects model was used to synthesize HR and OR if there was no significant heterogeneity among studies; otherwise, a random-effects model was employed.There were ten studies with 4625 patients included in the study, 3667 of whom (79.3%) were esophageal squamous cell carcinoma (ESCC). The HD-RT group had no significant benefits in overall survival (OS) (HR = 0.88, 95% confidence interval [CI] = 0.74-1.05, P = 0.16) and progression-free survival (HR = 0.84, 95%CI = 0.67-1.04, P = 0.12) in total EC patients, compared with SD-RT group. However, in ESCC subgroup analysis, compared with SD-RT group, a better OS was observed in the HD-RT group (HR = 0.78, 95%CI = 0.70-0.88, P < 0.0001).Compared with the radiation dose of 50-50.4 Gy, the increase of radiation dose (≥60 Gy) did not achieve benefits in survival for inoperable EC patients receiving CCRT. However, in patients with ESCC, high dose (≥60 Gy) of radiation probably improved OS.