Review for 10.1186/s12876-019-0996-y (2019)

Reviewer ’s report  
 
Title: Can the rate and location  of Sessile Serrated Polyps be Part of Colorectal Cancer Disparity 
in African Americans?  
 
Version: 0 Date: 25 Feb 2019  
 
Reviewer: Wael El -Rifai  
 
Reviewer's report:  
 
The authors conducted a large retrospective colonoscopy study that included 10,027 African 
American (AA) patients. Among AAs, pathology reports confirmed 4,070 patients with polyps 
including 252 with sessile serrated polyps (SSPs). The results are indeed i ntriguing showing the 
prevalence of SSPs accounts for 6% of all polyps in AA patients which is higher than Caucasians 
in the US. SSPs in African American patients were predominantly located in the left side, as 
compared to published literature showing the predominance in the right side of the colon. This is 
the largest study in AA this reviewer is aware of and provides important new information that 
could have significant diagnostic impact. The results can also fuel research in this area. The 
results could reflect differences in genetic risk factors and perhaps the etiology of SSPs in AA 
versus Caucasians. The results also suggest that colonoscopy should be carefully conducted in 
AA to detect SSP in the left colon. The discussion fails to address the inciden ce of SSPs in 
Hispanics and Asian. It will be equally important to discuss differences among population and 
ethnicity, if data exists. In addition, the authors need to speculate about possible reason for this. 
Are these genetic differences or differences i n other factors such as diet and/or alterations in the 
microbiome? An additional discussion is needed about the clinical impact of the findings in the 
context of CRC diagnosis and prognosis.  
Are the methods appropriate and well d escribed?  
If not, please 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 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 r ecommended, please specify what aspects 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  
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1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
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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?  
 
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below.  If your reply is y es to any, please give details below.  
 
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