Published online Jun 15, 2020. doi: 10.4251/wjgo.v12.i6.687
Peer-review started: January 23, 2020
First decision: March 24, 2020
Revised: April 9, 2020
Accepted: April 28, 2020
Article in press: April 28, 2020
Published online: June 15, 2020
The optimal time interval for esophagectomy after neoadjuvant chemoradiotherapy (nCRT) in patients with esophageal cancer has not been defined.
Some studies have revealed that a prolonged interval (> 8 wk) between nCRT and esophagectomy is associated with a higher pathological complete response, which may improve survival in esophageal cancer patients. However, others have indicated that the prognostic role of the time interval in esophageal cancer is still controversial. For these reasons, it is necessary to perform a meta-analysis to systematically and comprehensively investigate the impact of different intervals on survival outcome in these patients.
To evaluate whether a prolonged time interval between the end of nCRT and surgery has an effect on survival outcome through meta-analysis.
The research methods meta-analysis that were adopted to realize the objectives.
The results demonstrated that esophageal cancer patients with a prolonged time interval between the end of nCRT and surgery had significantly worse overall survival (OS) (HR: 1.107, 95%CI: 1.014-1.208, P = 0.023) than those with a shorter time interval. Subgroup analysis showed that poor OS with a prolonged interval was observed based on both the sample size and HRs. There was also significant association between a prolonged time interval and decreased OS in Asian, but not Caucasian patients. In addition, a longer waiting time resulted in worse OS (HR: 1.385, 95%CI: 1.186-1.616, P < 0.001) in patients with adenocarcinoma.
This meta-analysis confirmed that a prolonged time interval between the completion of nCRT and surgery is related to decreased OS of esophageal cancer patients. It is suggested that esophagectomy should be performed within 7-8 wk after nCRT in view of OS, especially in patients with good recovery and response to nCRT.
Several limitations in this analysis should be carefully addressed. The most important limitation was the fact that most of the studies included were retrospective. An additional uncontrolled factor is that heterogeneity was a potential factor that may have affected interpretation of the results. The source of heterogeneity in this study could be age, nCRT regimen, cut-off value, and ypTNM stage. As some potential biases were hardly adjusted, further well-designed and large-scale studies are needed to determine whether the time interval from the end of nCRT to surgery has an effect on survival outcome and to assess whether disease-specific survival differs by type of pathological response.