Review for 10.1186/s12876-016-0526-0 (2016)

Reviewer ’s report  
Title : HIGH PREVALENCE OF ADVANCED C OLORECTAL NEOPLASIA IN THE T HAI 
POPULATION: A PROSPECTIVE SCREENING COLON OSCOPY OF 1,404 CASES  
 
Version : 0 Date:  19 Feb 2016  
 
Reviewer:  Alexander Link  
 
Reviewer's report:  
Colorectal cancer is a deadly disease with available screening and prevention opportunities. In 
this work, the authors screened a sufficiently large group of volu nteers for colon neoplasia 
including CRC.  
 
Overall, the paper is well written and easy to follow.  
The authors should/may consider following recommendations:  
 
Major comments:  
1) Description of FIT analyses is not sufficient. Please, include detailed inform ation of the 
protocol. When were the samples collected (bevor colonoscopy or after, how long after the 
colonoscopy)? Volume? How were the samples stored and collected? Transportation? 
Quality controls? Is there any validation of the "device"? Are there any  study to support the 
quality at least comparison to alternative methods?  
2) Manuscript would benefit from detailed description of adenomas (locations, histological 
decryption). How many high grade adenomas were detected?  
3) For the FIT analyses, descripti on of the positive and negative patients is needed (including 
histology). What are the precise data to adenomas?  
4) If the FIT -analyses were not the primary aim of the study, it may be difficult to access the 
exact sensitivity and specificity. Secondly, it  could be possible that this device specifically 
is not sufficient enough for CRC screening? In the study cohort there were patients with 
UICC 0 stage tumors and one with neuroendocrine tumor, it is probably not surprising to 
obtain such a lower statistica l data. It is clear that FIT cannot be as good as colonoscopy, 
however, certain factors may be further important to consider in the population: cut off 
values etc.?  
 
Minor comments:  
1) Abstract line 27: UICC stage?  
2) Please include the description of the follow -up protocol in material and methods (time point 
and consideration of the follow -up colonoscopy)? Where there any CRC in subjects 
without follow -up colonoscopy?  
3) Having shown that most detected tumors were f ound in distal part of the colon, one may 
probably recommend recto -sigmoidoscopy. Authors may wish to discuss this.  
4) There is potential bias in the study as almost 70% of participants were females and only 
30% in males. It would be interesting to know th e gender proportions in adenoma groups 
and CRC.  
5) Page 10 line 35: " non -adenomatous polyps can accumulate worse genetic changes". 
Hyperplastic polyps are considered as non -preneoplastic condition in the left colon. The 
authors should support the statemen t by the reference.  
 
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.  
Yes 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an 
additional statistica l 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 i n 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 have no competing interests.  
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