Title: The impact of varying levels of residual disease following cytoreductive surgery on
survival outcomes in patients with ovarian cancer: a meta-analysis
Version: 2 Date: 09 Dec 2023
Reviewer's report:
The study sought to evaluate how different levels of residual disease status affect survival
outcomes in ovarian cancer patients undergoing primary or interval cytoreductive surgery amid
new therapeutic approaches. While the overall study is commendable, I've raised some major
and minor points to enhance the manuscript.
Major concerns
1. Heterogeneity and study design
The paper mentions substantial heterogeneity in patient baseline characteristics and reported
variables across the studies, which can significantly impact the reliability of the meta-analysis.
It is essential to address how the heterogeneity was managed or considered in the analysis,
especially when applying a random-effects model.
The inclusion of various study designs (observational studies, retrospective analyses, and
randomized controlled trials) raises concerns about potential biases and confounding factors.
The impact of these differences on the validity of the meta-analysis should be thoroughly
discussed.
2. Design of residual disease
The paper highlights variations in the definition of residual disease across studies. This
inconsistency might introduce bias into the analysis. It is crucial to provide a detailed discussion
on how this variability was handled and whether it might have influenced the results.
The inclusion of patients with no residual disease in the >0–1 cm category in some studies raises
questions about the consistency and accuracy of the categorization. Clarification on how this
potential overlap was addressed is necessary.
3. Limited data and in-depth analysis
The limitations related to the availability of data on diagnosis, disease stage, and histology
are acknowledged. However, the paper should discuss how these limitations might affect the
robustness of the conclusions, especially considering the importance of these factors in ovarian
cancer prognosis.
The statement about limited data preventing robust conclusions regarding factors affecting
overall survival and progression-free survival needs to be expanded. Readers should be informed
about the potential impact of these limitations on the generalizability of the findings.
4. Temporal bias and treatment landscape changes
The paper notes the temporal bias due to changes in the ovarian cancer treatment landscape,
specifically the introduction of new therapies like PARP inhibitors. The potential influence of
these changes on the outcomes and the generalizability of the results to current practice should
be discussed in more detail.
Minor comments
1. Reporting quality
The paper mentions limitations related to the predominance of observational studies. It would
be helpful to elaborate on how the quality of reporting in observational studies was assessed and
whether any quality threshold was set for inclusion in the meta-analysis.
2. Clinical relevance and implications
While the paper discusses the implications for practice and future research, a more
comprehensive discussion on the clinical relevance of the findings and how they might impact
patient care is warranted.
3. Lack of doi in the reference list
Please add doi to the reference list.