Review for 10.1186/s12876-024-03502-6 (2024)

Title: Long-term Outcomes of Additional Surgery Versus Surveillance-Only Clinical
Decision for Early Colorectal Cancer Patients After Non-curative Endoscopic Resection: A
Meta-analysis
Version: 4 Date: 22 Sep 2024
Reviewer's report:
The manuscript addresses an important and clinically relevant question by comparing long-
term outcomes between additional surgery and surveillance-only approaches for early colorectal
cancer (CRC) patients after non-curative endoscopic resection (ER). The greatest limitation
of this study is the unclear definition of noncurative resection. Noncurative resection can be
broadly divided into two categories: positive margins and high risk of lymph node metastasis,
but the clinical significance of the results of analyses that combine these two categories is highly
questionable. Regardless of the previous revision, the language quality is still not satisfied. It is
strongly recommended to be edited by professional editing service. Below are several specific
comments that should be addressed to strengthen the manuscript.
Specific Comments:
1. (Introduction) The introduction does a good job of laying out the controversy surrounding
additional surgery versus surveillance after non-curative ER. However, it could benefit from a
brief mention of the clinical characteristics that typically define high-risk early CRC patients
who are more likely to benefit from surgery.
2. (Introduction) Consider adding more details regarding the difficulties clinicians face in
deciding between additional surgery and surveillance-only strategies for non-curative ER
patients.
3. (Methods) The design of all included studies should be mentioned in the main body and Table
1.
4. (Methods) (Medical Databases and Search Strategy) It is recommended to specify whether
one or two independent reviewers screened titles and abstracts, as well as full-text articles. If
two reviewers were used, mention the process for resolving disagreements. If only one reviewer
was involved, it is important to discuss the potential for bias and provide a rationale for why this
approach was used (e.g., resource limitations).
5. (Methods) (Data Extraction and Methodological Quality Assessment) About “inclusion
criteria for endoscopic therapy”; It should be explicitly stated that the inclusion criterion refers
to whether the studies adhered to JSCCR guidelines or non-JSCCR guidelines for endoscopic
therapy. This important distinction, which is discussed later in the manuscript, should be
introduced in this section to give context to the data extraction process. Should briefly explain
what the JSCCR guidelines detail regarding endoscopic therapy. For example, the JSCCR
guidelines provide specific recommendations for patient eligibility, tumor characteristics, and
indications for endoscopic resection, which could impact the inclusion of studies. A short
summary of these guidelines will help readers unfamiliar with the JSCCR understand their
relevance.
6. (Methods) (Statistical methods) Authors analyzed and showed that an OR of >1 as favored
data for experimental group (i.e., additional surgery group). Usually, it is shown in the opposite
direction.
7. (Results) (DSS, DFS, RFS) The headings of sections are recommended not to be abbreviated.
8. (Results) (Local recurrence, distant and lymph node metastasis) The definition of “local
recurrence” should be clearly mentioned. It means only intramural recurrence or overlapped
with lymph node metastasis?
9. (Results) (Subgroup analysis for inclusion criteria) The abbreviation of “RR” appeared here
for first time without full spelling. Please correct it. Besides, the description of Figure “9A” is
missing in the main body.
10. (Discussion) (Disease-Free Survival and Recurrence-Free Survival) DFS and RFS section
reports no significant difference between additional surgery and surveillance-only groups, which
contrasts with the findings for OS. However, the reasons for this lack of significance are not
fully explored. Further discussion is needed to explain why these results differ from OS and
recurrence rates, and whether this might be related to differences in study design, follow-up
periods, or patient characteristics. Clarifying these aspects will improve the understanding of
these outcomes and their clinical relevance.
11. (Discussion) (Subgroup Analysis for JSCCR and Non-JSCCR) The discussion mentions that
inclusion criteria based on JSCCR guidelines impacted the outcomes of recurrence rate, but
this point could be expanded further. Why do you think the JSCCR inclusion criteria lead to
better outcomes in terms of recurrence? Does this suggest that adherence to specific guidelines
improves patient selection and overall treatment outcomes?