Review for 10.1186/s12876-015-0383-2 (2015)

Reviewer ’s report  
 
Title: Prognostic and clinical significance of syndecan -1 in colorectal cancer: a meta -analysis  
 
Version: 0 Date: 26 Aug 2015  
 
Reviewer: Andrew Rowland  
 
Reviewer's report:  
 
The authors present a meta -analysis of studies considering the role of syndecan -1 in colorectal  
cancer. Overall the quality of the analysis is good, and the conclusions are sound based on the 
data presented. There are however a number of minor points relat ing to the description of the  
methodology and conclusions that do require clarification. Given the limited number of studies  
identified and the small size of these studies, ensuring a comprehensive data collection is critical.  
When considering the search s trategy this reviewer would like a stronger justification for the  
rationale for excluding conference abstracts. Given that the identification of markers of CRC is  
currently an area of intense research, it is likely that ongoing research in the field may ha ve 
resulted in recent presentations at international meetings such as ASCO and ESMO. Can the  
authors confirm that the search strategy considered differences in truncation symbols and  
wildcards between databases? Were relevant MeSH (Medline) or Emtree (Emba se) terms were  
used where possible? Given that this is manuscript reports a meta -analysis of existing data, (page  
5, line 9) it is unclear which 'participants signed an informed  consent to participate in this 
study'?In  the exclusion criteria, can the autho rs provide some additional information regarding 
the 4th exclusion criteria 'low -quality studies'; this is a particularly vague and subjective criteria 
that needs  to be better qualified.For readers outside of the direct field a justification of the 
rationa le for  excluding studies the detected syndecan -1 expression by methods other than IHC 
would be useful.  Given that IHC detection method was considered in the quality assessment it 
would be nice to  clearly justify why other detection methods could not simila rly have been 
considered and scored  accordingly.The authors claim that their finding is consistent with the 
finding of Fujiya et al.,  2001, however the conclusions of Fujiya et al., 2001 that 'results suggest 
that the reduction of  syndecan -1 expression in colorectal cancer cells, which is supposed to be 
regulated at the  transcription level, is closely related to invasive character. The evaluation of 
syndecan -1 expression in colorectal cancer may allow prediction of patients' survival after 
surgery' directly  contrast the conclusion of the current meta -analysis. This discrepancy needs to 
be addressed.  
 
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 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 follo wing 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 comp eting 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 report  
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to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal