Review for 10.1186/s12876-019-0949-5 (2019)

Reviewer’s report  
 
Title: Clinicopathologic characteristics of early gastric cancer acc ording to specific intragastric 
location  
 
Version: 0 Date: 24 Nov 2018  
 
Reviewer: Hyo-Joon Yang  
 
Reviewer's report:  
 
Comments to the Author:  
 
In this cross -sectional study, the authors evaluated clinicopathological characteristics of early 
gastric cancers (EGCs) according to the anatomical intragastric location both in vertically and 
transversely. The authors found that EGCs with different anato mical location were associated 
with different age, tumor size, and tumor differentiation. This study is relatively well conducted 
and well written. However, it seems necessary more explanation about clinical importance and 
applicability of the study result s.   
 
1. Abstract  
It is recommended to describe the findings with actual numbers (e.g. percentages or mean 
numbers) in the results section.  
 
2. Introduction  
It does not seem to be explained enough why this study is necessary in the Introduction section. 
Although the authors discussed the importance of intragastric location of EGCs with regard to 
the endoscopic resectability, there is no further discussion rega rding this point throughout the 
other parts of the manuscript. The introduction section needs to be more focused and more 
justified with the necessity of the current study.  
 
3. Methods and Results  
Were there any reasons why advanced gastric cancers were n ot included in this study? I think 
this can be potential source of selection bias. For example, middle third location was associated 
with undifferentiated histology EGCs, not entire gastric cancers in this study. If undifferentiated 
advanced gastric cancer s were more prevalent in other locations of the stomach, the findings of 
the current study may provide misleading pictures in the association of gastric cancer location 
and tumor differentiation.  
 
4. Methods and Results  
What was the reason the authors used  'merged tumor map'?  
The locations were well described in the Table 2, and the merged tumor map included only 
surgically resected cases. So, it seems that there is not so many advantages in using this map.  
It is recommended to provide more explanations on  why this map is necessary and what 
additional information can be found from this map.  
 
5. Discussion  
The Discussion section was focused on the comparison of the findings from the current study 
and those from previous literature. However, the explanations of the clinical importance and 
applicability of the current findings were relatively deficient. I think these points should be 
augmented in the Discussion section.  
 
Are the methods appropriate and well described?  
If not, please speci fy 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 data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
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 your 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 publica tion 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 fin ancial 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 am in the same institution with the authors of the current manuscript.  
 
I agree to the open peer review policy of the journal. I understand that my name will  be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
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 unde r an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal