Published online Apr 15, 2020. doi: 10.4251/wjgo.v12.i4.503
Peer-review started: November 7, 2019
First decision: December 5, 2019
Revised: February 27, 2020
Accepted: March 22, 2020
Article in press: March 22, 2020
Published online: April 15, 2020
Processing time: 160 Days and 1.3 Hours
The use of chemotherapy (CTx) after curative surgery for non-metastatic rectal cancer and its role in improving patient survival remains controversial.
In 2012, Petersen et al[3] reported in a Cochrane review the effect of postoperative adjuvant CTx following curatively resected rectal cancer (Tany, Nany, M0) on overall survival. The authors identified 21 randomized controlled trials (RCT) reporting overall survival as primary endpoint. The meta-analysis of these RCTs showed a significant reduction in the risk of death (17%) among patients undergoing postoperative CTx as compared to those undergoing observation (hazard ratio = 0.83; 95% confidence interval: 0.76-0.91).
We aimed to analyze the quality of the data supporting the advantage of adjuvant CTx after surgery for rectal cancer.
Using the CONSORT Checklist, the current analysis evaluated the validity of the three most powerful studies reviewed and analyzed within the Cochrane review by Petersen et al[3] 2012 which support the survival benefit of adjuvant CTx.
The detailed analysis of the three most powerful studies highlighted inconsistencies including inappropriate answers in up to 47% of the items of the CONSORT checklist. Inadequate or unclear randomization without allocation concealment, missing blinded set-up, absence of intention-to-treat analysis and omission of sample size calculation were the most common findings.
We suggest a more critical appraisal regarding the validity of single RCTs, as these studies are included in meta-analysis that are the basis for guidelines.
As CTx has several side effects for the patient and generates costs for the health system, it should be used only if its benefit is real.