Review for 10.1186/s12876-020-01358-0 (2020)

Reviewer ’s report  
 
Title: Increased Incidence of Metachronous Gastric Neoplasm After Endoscopic Resection in  
Patients With Synchronous Gastric Neoplasm  
 
Version: 1 Date: 07 Apr 2020  
 
Reviewer's report:  
 
This is  a case control study about incidence of metachronous gastric neoplasms after endoscopic 
resection (ER). There is no novelty in terms of increased incidence of metachronous gastric 
neoplasms after endoscopic resection, but this study is unique because this  study includes not 
only cancers but also adenomas. I think that there are some problems about the methods and the 
conclusion. The followings may be taken into consideration.  
 
・This study protocol may not exclude local recurrence after ER because the posi tive surgical 
margin (including horizontal and vertical margins) of initial ER is not described and excluded. 
Metachronous lesions should not include local recurrence after ER.  
・Although synchronous lesion is one of risk factors of metachronus lesions, thi s study does not 
investigate and analyze the appropriate follow -up after ER. Therefore, the specific period of 
follow -up should not be described.  
 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your c omments to the authors.  
 
No 
 
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 data shown?  
If not, please explain in yo ur comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further  
assessment in y our comments to the editors.  
 
I am able to assess the statistics  
 
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, fees, 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 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 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  
 
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on my report to the authors and, if the manuscript is accepted for publication, my named rep ort 
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I agree to the open peer review policy of the journal