Meta-Analysis
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jun 15, 2020; 12(6): 687-698
Published online Jun 15, 2020. doi: 10.4251/wjgo.v12.i6.687
Timing of surgery after neoadjuvant chemoradiotherapy affects oncologic outcomes in patients with esophageal cancer
Qi-Xin Shang, Yu-Shang Yang, Yi-Min Gu, Xiao-Xi Zeng, Han-Lu Zhang, Wei-Peng Hu, Wen-Ping Wang, Long-Qi Chen, Yong Yuan
Qi-Xin Shang, Yu-Shang Yang, Yi-Min Gu, Han-Lu Zhang, Wei-Peng Hu, Wen-Ping Wang, Long-Qi Chen, Yong Yuan, Department of Thoracic Surgery, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China
Xiao-Xi Zeng, West China Biomedical Big Data Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Shang QX, Chen LQ and Yuan Y designed research; Shang QX, Yang YS, Gu YM, and Zhang HL performed research; Zeng XX and Hu WP contributed new reagents or analytic tools; Shang QX, Gu YM and Wang WP analyzed data; Shang QX wrote the paper; all authors approved the final version; Shang QX and Yang YS contributed equally to this work.
Supported by the National Natural Science Foundation of China, No. 81970481; Sichuan Science and Technology Program, No. 2018HH0150 and Chengdu Science and Technology Bureau, No. 2016GH0200020HZ.
Conflict-of-interest statement: The authors deny any conflict of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Yong Yuan, MD, PhD, Associate Professor, Department of Thoracic Surgery, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, Sichuan Province, China. yongyuan@scu.edu.cn
Received: January 23, 2020
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
ARTICLE HIGHLIGHTS
Research background

The optimal time interval for esophagectomy after neoadjuvant chemoradiotherapy (nCRT) in patients with esophageal cancer has not been defined.

Research motivation

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.

Research objectives

To evaluate whether a prolonged time interval between the end of nCRT and surgery has an effect on survival outcome through meta-analysis.

Research methods

The research methods meta-analysis that were adopted to realize the objectives.

Research results

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.

Research conclusions

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.

Research perspectives

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.