Effect of modern high-dose versus standard-dose radiation in definitive concurrent chemo-radiotherapy on outcome of esophageal squamous cell cancer: a meta-analysis

Background and objectives Radiation Therapy Oncology Group (RTOG) 94-05 has demonstrated that higher dose radiation didn't improve outcome of patients with esophageal cancer (EC). However, several retrospective studies showed that a higher dose radiation based on modern radiotherapy techniques could improve overall survival (OS) and local control rate (LCR) of patients with EC, especially esophageal squamous cell cancer (ESCC). As trials have provided updated and controversial data, we performed this updated meta-analysis to investigate whether high-dose (> = 60 Gy) radiotherapy in definitive concurrent chemo-radiotherapy (CCRT) could yield benefit compared to standard dose radiotherapy. Methods A systematic literature search was carried out in the database of MEDLINE, PubMed and Embase. All studies published between 1 January 1990 and 31 December 2018 on the association between radiation dose and curative efficiency in EC were included in this meta-analysis. The hazard ratio (HR) was used to evaluate the time-to-event data employing RevMan version 5.3. Results Eight articles with a total of 3736 patients were finally included. Results indicated that there was a significant benefit in favor of high dose radiotherapy (HD-RT) regarding OS (HR = 0.78, 95%CI: 0.72-0.84, p < 0.001; 2-year OS risk ratio (RR) = 1.25, 95%CI: 1.14-1.37, p < 0.001), progression-free survival (PFS) (P = 0.001, HR = 0.7, 95%CI: 0.57-0.87) and LRFS (P < 0.001, HR = 0.52, 95%CI: 0.36-0.74) . Conclusions HD-RT (> = 60 Gy) based on modern radiotherapy techniques in definitive CCRT appears to improve OS, PFS amd LRFS compared to the SD-RT in patients with ESCC.