Review for 10.1186/s12876-020-01340-w (2020)

Reviewer ’s report  
 
Title: The outcomes of modified endoscopic mucosal rese ction and endoscopic submucosal 
dissection for the treatment of rectal neuroendocrine tum ors and the value of endoscopic 
morphology classification in endos copic resection  
 
Version: 0 Date: 21 Apr 2020  
 
Reviewer: Sujin Kim  
 
Reviewer's report:  
 
This manuscript describe the clinical outc omes of various endoscopic resection for rectal NET. 
There are some comments to increase the quality of this manuscript.  
 
Major)  
 
1. The aim of this study is to compare the outcomes between modified endoscopic mucosal 
resection (EMR -L, EMR -C, and EMR -CI) an d endoscopic submucosal dissection.  
 
The evaluation for risk factors associated with incomplete resection were needed in two groups 
after propensity score matching to compare the effect of ER methods.  
 
2. A differentiation between Ib and II types is indefinite because the measurement of angle is not 
objective but subjective. The height of tumor (ex, using forcep) decrease the inter -observer 
variation. If it is not possible, the inter -observer agreement p rocess can reduce the bias.  
 
3. Authors concluded that ESD could be used for treating rectal NETs sized beween 1 to 2 cm. 
However, your results demonstrated that modified EMR such as EMR -CI can also effective 
treatment.  
 
4. In discussion, authors stated th at surgery such as transanal endoscopic microsurgery should be 
considered for lesions with risk factor related to incomplete resection. However, the prognosis of 
incomplete resection by endoscopic resection was not bad in this manuscript. Authors also 
performed an additional ESD to treat incomplete resection.  
 
Minor)  
 
1. Please describe the clinical outcomes of various EMR methods, respectively.  
 
2. Please provide the information of en -bloc and margin status in one recurrence case after ESD.  
 
3. A polypecto my and conventional EMR were categorized the different exclusion criteria. What 
is difference between two methods.  
 
Are the methods appropriate and well described?  
If not, plea se specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the dat a shown?  
If not, please explain in your comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what asp ects require further 
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
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, f ees, funding, or salary 
from an organisation that may in any way gain or lose financially from the 
publi cation of this manuscript, either now or in the future?  
 
2.  Do you hold any stocks or shares in an organisation t hat 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 curr ently 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 declare that I have no competing interests.  
 
I agree to the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted for publication, my named rep ort 
including any attachments I upload will be posted on the website along with the authors' 
responses. 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/ ). I understa nd that any comments 
which I do not wish to be included in my named report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal