Title: Utility of Vaginal Vault Cytology in the Local Recurrence of Cervical Cancer
Version: 3 Date: 10 Mar 2023
Reviewer's report:
Thank you for giving me this opportunity to review this interesting manuscript titled “Utility of
Vaginal Vault Cytology in the Local Recurrence of Cervical Cancer”. Overall, the manuscript
is well-written and easy to read , but there were several concerns.
Abstract
1. In the Background section, it is unclear whether the issue described is about regular checkups
for undiagnosed women or screening for recurrence after treatment. Please revise to clarify this.
2. In the Background section, it is unclear whether this study evaluated the association between
specific factors involved in surveillance and outcomes or whether it was an exploratory
evaluation of a large number of factors. Please correct to clarify.
3. In the Results section, the description should be revised to focus on "Vaginal Vault Cytology"
as stated in the title.
4. There seems to be a leap of logic in the description of the results and conclusions.
Introduction
1. Lines 75-80: Please clarify and correct whether surveillance with imaging analysis is not
recommended because it has little benefit in terms of cost–benefit balance or because it has not
been shown to improve long-term prognosis.
2. Lines 96-98: There was no mention of prior research on routine surveillance using vaginal
vault cytology. If both positive and negative results exist, please cite the literatures and add an
explanation.
3. Line 98: If the authors' research in this topic is the first time, "evaluated" should be used
instead of "re-evaluated".
Methods
1. Please describe a study design of the current study clearly in the Study design section.
2. Please describe in detail the inclusion and exclusion criteria for eligible patients in the Study
design section.
3.  in the Statistical analyses section, please list all factors evaluated and describe a reason for
choice of those factors as patient characteristics. Also specify whether all patient background
factors were used in univariate analysis.
4. Did the authors perform a proportional hazard assessment in each survival time analysis?
Please specify whether and how it was performed. Also, please add results of the proportional
hazard assessment.
5. The variables used in the Cox regression analysis could have strong interrelationships. The
authors used the stepwise variable selection method for multivariate analysis, but did they
evaluate multicollinearity? If they did, please specify the results.
6. Were P-values assessed as two-tailed? Please state it clearly.
Results
1. If any patients were excluded in the patient selection, please create a diagram showing the
selection process.
2. 9% of 981 patients would be 88, but there is a discrepancy as it is stated that there were 84
patients with recurrence.
3. It is unclear what each value in Table 1 represents. Please clearly provide an explanation.
4. The titles of Tables 2 and 3 are exactly the same, and the differences are not clear. Please
provide details on the analyses corresponding to Tables 2 and 3 respectively in the Methods
section and revise the titles.
5. Lines 181-182: The sentence of “We further investigated factors affecting survival after
recurrence “ should be described in the Methods section.
6. The authors stated that the purpose of this study was to evaluate the benefit of surveillance,
and they may have intended to examine whether specific factors of surveillance were associated
with outcomes. However, the authors mentioned initial treatment, site of recurrence, and salvage
therapy  used as adjustment factors in the table 2 and 3, which is inconsistent and inappropriate
study design. Please be clear about whether the study is evaluating the association between
specific risk factors and outcomes or an exploratory assessment of risk factors, and be consistent
in the introduction, methods, results, and discussion.
7. All figures should be marked with No. at risk.
8. Regarding the retrospective nature of this study and the small sample size listed as limitations,
please specify how these may have affected the results.
Discussion
1. A brief summary of the results obtained in the first paragraph will help the reader understand.
2. Please be clear about whether the study is evaluating the association between specific risk
factors and outcomes or an exploratory assessment of risk factors, and be consistent in the
introduction, methods, results, and discussion.
Conclusions
1. The first line of text is unnecessary and should be deleted.