Meta-Analysis
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Sep 15, 2021; 13(9): 1196-1209
Published online Sep 15, 2021. doi: 10.4251/wjgo.v13.i9.1196
Neoadjuvant chemotherapy without radiation as a potential alternative treatment for locally advanced rectal cancer: A meta-analysis
Pei Wu, Hui-Mian Xu, Zhi Zhu
Pei Wu, Department of Gastrointestinal Surgery, Yongchuan Hospital of Chongqing Medical University, Chongqing 402160, China
Pei Wu, Hui-Mian Xu, Zhi Zhu, Department of Surgical Oncology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
Author contributions: Wu P and Zhu Z contributed to study concept and design, acquisition of data, analysis and interpretation of data, and drafting of the manuscript; Wu P, Zhu Z, and Xu HM performed statistical analysis.
Supported by National Natural Science Foundation of China, No. 81302129.
Conflict-of-interest statement: The authors have no competing interests to declare.
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: Zhi Zhu, PhD, Doctor, Department of Surgical Oncology, The First Hospital of China Medical University, No. 155 Nanjing Street, Shenyang 110001, Liaoning Province, China. zhuzhi@cmu.edu.cn
Received: February 6, 2021
Peer-review started: February 6, 2021
First decision: May 8, 2021
Revised: June 1, 2021
Accepted: July 19, 2021
Article in press: July 19, 2021
Published online: September 15, 2021
Processing time: 215 Days and 17.2 Hours
Abstract
BACKGROUND

Neoadjuvant chemoradiotherapy (Neo-CRT) is the current standard strategy for treating locally advanced rectal cancer. However, it delays the administration of optimal chemotherapy and increases toxicity.

AIM

To compare the feasibility and efficacy of neoadjuvant chemotherapy (Neo-CT) and Neo-CRT for patients with locally advanced rectal cancer.

METHODS

The Cochrane, EMBASE, and PubMed databases were searched for relevant articles using MESH terms and free words. The hazard ratio of overall survival and the risk ratio (RR) for the pathological complete response, the sphincter preservation rate, and treatment-related adverse events were analyzed.

RESULTS

A total of 19 studies of 60870 patients were included in the meta-analysis. There was no significant difference in overall survival [hazard ratio = 1.09, 95% confidence interval (CI) = 0.93–1.24; P = 0.19] or the pathological complete response (RR = 0.79, 95%CI = 0.61–1.03; P = 0.086) between the Neo-CT and Neo-CRT groups. As compared to the Neo-CRT group, the incidences of anastomotic fistula (RR = 0.49, 95%CI = 0.35–0.68; P = 0.000) and temporary colostomy (RR = 0.69, 95%CI = 0.58–0.83; P = 0.000) were significantly lower in the Neo-CT group, with a simultaneous increase in the sphincter preservation rate (RR = 1.07, 95%CI = 1.01–1.13; P = 0.029). However, there was no significant difference in the tumor downstaging rate, overall complications, and urinary complications.

CONCLUSION

Neo-CT administration can lower the incidences of anastomotic fistula and temporary colostomy and increase the sphincter preservation rate as to compared to Neo-CRT and could provide an alternative to chemoradiotherapy for locally advanced rectal cancer.

Keywords: Rectal cancer; Neoadjuvant chemotherapy; Chemoradiation; Prognosis

Core Tip: Neoadjuvant chemoradiotherapy acts as standard treatment in locally advanced rectal cancer (LARC). However, it delays the administration of optimal chemotherapy and increases toxicity. We designed the meta-analysis to compare the feasibility and efficacy of neoadjuvant chemotherapy vs neoadjuvant chemoradiotherapy for the treatment of LARC. The present study showed that neoadjuvant chemotherapy was effective for the treatment of LARC, especially to lower the incidences of anastomotic fistula and temporary colostomy and increase the sphincter preservation rate as compared to neoadjuvant chemoradiotherapy. This could have the potential to provide an alternative to chemoradiotherapy for LARC.