Review for 10.1186/s12876-021-01700-0 (2021)

Reviewer’s report
Title: 
Clinical outcomes of early gastric cardiac cancer treated with endoscopic
submucosal dissection in patients with different indications
Version: 
4 
Date: 
24 Nov 2020
Reviewer's report:
The author has corrected the manuscript well, but I still have something to
correct.
Regarding "At this time, the risk of death from additional surgery is already
higher than risk caused by the disease itself." in p19, line 11, in this study, 2 of
45 non-additional surgery patients in the BEI group died of gastric cancer due to
metastasis, and both patients died within 20 months after ESD in Fig.1D. The
mortality rate for these non-additional surgical cases is 4.4% (2/45), which is
higher than the 2.4% (1/42) mortality rate for additional surgical cases. Due to
the small number of cases, there was no significant difference in 5-year survival
with or without additional surgery, but I think that the relatively early deaths of
the two non-additional surgery cases cannot be ignored. If the two patients
received additional surgery, they might not have died of stomach cancer. I think
this point should be included in the discussion part.
Takizawa et al. examined the same cases as eCura system literature by Hatta et al
in the following literature. (Takizawa K, Hatta W, Gotoda T, et al. Recurrence
Patterns and Outcomes of Salvage Surgery in Cases of Non-Curative Endoscopic
Submucosal Dissection without Additional Radical Surgery for Early Gastric
Cancer. Digestion. 2019; 99: 52-8.)
According to the literature, out of 905 patients who did not undergo surgery with
eCura C2, 27 patients (2.9%) had recurrence of stomach cancer, and the median
survival time was reported to be 5 months. In this study, 4.4% of patients
without additional surgery die of gastric cancer, so it should be clearly stated in
the discussion part that easy refusal of additional surgery should be avoided by
quoting that Takizawa's literature.
Is "our previous study" on the 3rd line of P5 equivalent to reference no.1?
Please correct the location of citations in the literature.
Regarding the paragraph of "Long-term therapeutic outcomes according to the
indication" 
in the results.(p13-14), there are many mistakes in the text and Tables
3 and 4. Please correct each.
Regarding Figure 1G, two people died in the surgery group. There should be
one death in the surgery group, so please correct it.
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
No
Declaration of competing interests
Please complete a declaration of competing interests, considering the following
questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I have no competing interests to declare.
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
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
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes