Review for 10.1186/s12876-017-0574-0 (2017)

Reviewer ’s report  
 
Title:  Endoscopic imaging modalities for diagnosing invasion depth of superficial esophageal 
squamous cell carcinoma: a systematic review and meta -analysis  
 
Version: 0 Date: 25 Nov 2016 
 
Reviewer:  Wen -Lun Wang  
 
Reviewer’s report:  
 
Comments to the Author  
 
 In this article, the authors reported a meta -analysis to assess the diagnostic performance of the 
three endoscopic modalities in predicting cancer invasion depth of superficial ESCCs. They 
found magnifying endoscopy (ME) and EUS have better diagnostic accuracy than conventional 
white -light endoscopy. ME was associated with high sensitivity, while EUS had high specificity 
to differentiate the epithelial/lamina propria cancers from  MM-SM2 invasion cancer. The topic 
of this article is interesting, but I have the following comments.  
 
 
Major and specific comments:  
 
1. In the Method section, the authors describe they searched the MEDLINE, Cochrane Central, 
and Ichushi databases. But in th e Results section, they reported 18 additional records were 
identified through "manual searching" of references. The criteria and database of "manual 
searching" should be clarified in the Method section. Whether the manual searching will cause 
selection bi as and violate the principle of systemic review? How many studies derived from 
manual searching are included for final analysis?  
 
2. Among the final 14 studies included for analysis, all studied in Japan, and 11 of them are 
published in Japanese only. These  weak points should be mentioned and discussed.  
 
3. The "sm2 group" in the article should be modified as " ≧sm2", because these cases included 
the sm2, sm3 or even deeper invasion cancers.   
 
4. In Table 1. (the column of the study design), what does the "Pr os/Retro." mean?  This 
descriptor seems inappropriate. All of these studies are cross -sectional studies. In addition, we 
suggest the authors to add some columns in Table 1, to describe the image -enhanced modalities 
(ex. NBI); the classification system of m agnification; and the types and probe frequency of EUS.   
 
5. How many cases using non -ME, ME or EUS included for the final analysis should be 
described, respectively.  
 
6. In Figure 4., the values of sensitivity, specificity (95% CI) of each study should be  described 
in the figure.   
7. The I2 index and Q -index should be mentioned in the results.  
 
8. The Figure 1. is redundant and unnecessary.  
  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments 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.  
 
Unable to assess  
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comm ents 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 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:  
 
Needs some language corrections before being published  
 
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 o f 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 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 websi te along with the authors' 
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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