Reviewer’s report
Title: 
The potential risk of contralateral non-sentinel groin node metastasis in
women with early primary vulvar cancer following unilateral sentinel node
metastasis: a single center evaluation in University Hospital of Düsseldorf
Version: 
0 
Date: 
16 Sep 2020
Reviewer's report:
I read with interest this work from Winarno and colleagues and the topic is of
great relevance in the literature. As highlighted by the authors, according to main
international guidelines, SLNB can be considered the standard of care for
selected women with VC. Currently, in case of positive SLNB, a bilateral IFL
dissection is suggested, especially for midline vulvar lesions. However, the
surgical procedure has a high rate of side effects the patient (and gynecologist)
should be aware of. For this reason, is interesting to evaluate the opportunity to
safely avoid the IFL at least in one groin. It is therefore interesting to observe
what happened in women in which only monolateral dissection was performed. 
However, even if the topic is interesting, in my opinion a major review is
necessary before this work can be considered suitable for publication.
First of all: the English language needs to be improved throughout the whole
manuscript. I suggest a professional linguistic review in order to make the paper
more intelligible to the readers. 
The background section should be shortened and should be only focused on the
main theme of the work. Please avoid such a long dissertation about histological
classification, risk factors, signs and symptoms and the spread of VC cells. This
is not a systematic review about VC, and all this information are well known to
those who are interested in the topic of SNLB. 
In the background section, the authors should focus only on surgical
management of VC and IFL. A proper paragraph about the clinical relevance
(and outcome) of nodal involvement in women with VC should be added. The
benefits (but also the potential limitations) of SLNB compared to IFL should be
introduced in this section. Even if SLNB is considered a standard of care, not all
the patients with VC are suitable for the procedure. Moreover, the procedure
itself should be performed only in dedicated hospitals, by surgeons with
particolar expertise and adequate number of procedures-per year performed. This
potential limitations of SLNB procedure should be mentioned in the background
section.
The reference to recent published by Woelber and Nica should be better moved
in the discussion section. A proper paragraph highlighting the aim of the work
should be put in the end of background section. 
The methods section should be improved as well. The inclusion/exclusion
criteria should be clearly reported. For this evaluation only women with stage IB-
II VC should be included in the analysis. 
The authors stated that "vulvar tumor was resected locally with < 3mm tumor
free margin". Have the women with closer surgical margin been excluded? are
there other exclusion criteria?
Only women with minimum 12 months follow up were included. However,
considering the published data about VC recurrence, a minimum 24 months
follow up should be more appropriate. If this is not possible, the authors should
discuss this as a potential limitation of the study.
In the result section, since the authors want "to emphasize on the side effects and
post surgical complication" a comparison between women with unilateral IFL vs
bilateral IFL should be performed, evaluating the rate of inguinal complications
in both groups. A proper table will help to clarify this comparison.
The discussion section should be shortened and better focused on the paper's
topic. In particular, the discussion should be focused on SNLB, its indications
and potential limitations. The impact groin recurrence on patient's survival
should be discussed, as well as the potential side effects of traditional IFL.
It is interesting to report a case of VC diagnosed in pregnancy. However, since
it's only one case, such a long paragraph in the discussion section is not
necessary and should be shortened. In line 240 The authors wrote "potential risk
of vulvar biopsy resulting in feto-martenal complications"; please add a proper
reference for that.
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Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
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Yes
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes