Meta-Analysis
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jan 15, 2021; 13(1): 69-86
Published online Jan 15, 2021. doi: 10.4251/wjgo.v13.i1.69
Efficacy and safety of intraoperative radiotherapy in rectal cancer: A systematic review and meta-analysis
Bin Liu, Long Ge, Jing Wang, Ya-Qiong Chen, Shi-Xun Ma, Pei-Lan Ma, Yun-Qiang Zhang, Ke-Hu Yang, Hui Cai
Bin Liu, Ya-Qiong Chen, Shi-Xun Ma, Pei-Lan Ma, Yun-Qiang Zhang, Gansu Provincial Hospital, General Surgery Clinical Medical Center, Lanzhou 730000, Gansu Province, China
Long Ge, Evidence Based Social Science Research Center, School of Public Health, Lanzhou University, Lanzhou 730000, Gansu Province, China
Jing Wang, Gansu University of Chinese Medicine, Gansu University of Chinese Medicine, Lanzhou 730000, Gansu Province, China
Ke-Hu Yang, Evidence Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China
Hui Cai, General Surgery Clinical Medical Center, Gansu Provincial Hospital, Lanzhou 730000, Gansu Province, China
Author contributions: Liu B, Ge L, Yang KH, and Cai H designed the research; Liu B, Wang J, Chen YQ, Ma SX, and Ma PL conducted the literature search; Liu B and Ge L collected and retrieved the data; Liu B, Zhang YQ, and Wang YF analyzed the data; Liu B wrote and revised the manuscript; All authors approved the final version.
Supported by Natural Science Foundation of Gansu Province, China, No. 18JR3RA052; Gansu Province Da Vinci robot high end diagnosis and treatment personnel training project; National Key Research and Development Program Task Book, No. 2018YFC1311506; Lanzhou Talent Innovation and Entrepreneurship Project Task Contract, No. 2016-RC-56; 2019 Graduate Innovation Fund Project, No. 2020CX50.
Conflict-of-interest statement: No conflicts of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised.
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: Hui Cai, MD, PhD, Chief Doctor, Director, Professor, Surgical Oncologist, General Surgery Clinical Medical Center, Gansu Provincial Hospital, Lanzhou 730000, Gansu Province, China. caialonteam@163.com
Received: November 10, 2020
Peer-review started: November 10, 2020
First decision: November 30, 2020
Revised: December 6, 2020
Accepted: December 16, 2020
Article in press: December 16, 2020
Published online: January 15, 2021
Processing time: 58 Days and 1 Hours
ARTICLE HIGHLIGHTS
Research background

The prognosis of patients with rectal cancer is poor and the mortality rate is high. The effectiveness and safety of intraoperative radiotherapy (IORT) for rectal cancer still controversial.

Research motivation

Previous studies have demonstrated that adding IORT to traditional treatment of rectal cancer not only reduces the local recurrence rate of advanced rectal cancer but also influences the local control rate of locally recurrent rectal cancer. However, a recent randomized controlled trial (RCT) showed that IORT cannot be recommended as a standard therapy to compensate less radical resection for advanced lower rectal cancer. It is necessary to perform a meta-analysis to systematically and comprehensively investigate the effectiveness and safety of IORT in the treatment of rectal cancer.

Research objectives

A systematic review and meta-analysis to evaluate the value of IORT for patients with rectal cancer.

Research methods

We searched PubMed, Embase, Cochrane Library, Web of Science databases and conference abstracts and included RCTs and observational studies on IORT vs non-IORT for rectal cancer. Dichotomous variables were evaluated by odds ratio (OR) and 95% confidence interval (CI), hazard ratio (HR) and 95%CI was used as a summary statistic of survival outcomes. Statistical analyses were performed using Stata V.15.0 and Review Manager 5.3 software.

Research results

In this study, 3 RCTs and 12 observational studies were included with a total of 1460 patients, who were mainly residents of Europe, the United States, and Asia. Our results did not show significant differences in 5-year overall survival (HR = 0.80, 95%CI = 0.60-1.06; P = 0.126), 5-year disease-free survival (HR = 0.94, 95%CI = 0.73-1.22; P = 0.650); abscess: (OR = 1.10, 95%CI = 0.67-1.80; P = 0.713); fistulae (OR = 0.79, 95%CI = 0.33-1.89; P = 0.600); wound complication (OR = 1.21, 95%CI = 0.62-2.36; P = 0.575); anastomotic leakage (OR = 1.09, 95%CI = 0.59-2.02; P = 0.775); and neurogenic bladder dysfunction (OR = 0.69, 95%CI = 0.31-1.55; P = 0.369). However, the meta-analysis of 5-year local control was significantly different (OR = 3.07, 95%CI = 1.66-5.66; P = 0.000).

Research conclusions

The advantage of IORT is mainly reflected in 5-year local control but it is not statistically significant for 5-year overall survival, 5-year disease-free survival, and complications.

Research perspectives

Several limitations in this analysis should be carefully addressed. First, the randomization in the original research was limited. There were few controlled experiments and the sample size was irregular. Second, although most patients were treated in large tertiary cancer centers, the inclusion criteria for patients were different. Moreover, during treatment, the assessment methods of the outcome index was related to the proficiency of the surgeon. In addition, there were differences in the surgical procedures in this research, which may be a confounding factor for the results. Finally, our research is a secondary study and differences in the original data cannot be controlled for, including experimental design, inclusion criteria, and the original study included, which may affect the reliability of the results.