Review for 10.1186/s12876-015-0399-7 (2015)

Reviewer ’s report  
 
Title:  Outcomes and risk factors for cancer patients undergoing endoscopic intervention of  
malignant biliary obstruction  
 
Version: 0 Date: 12 Sep 2015  
 
Reviewer:  Conrado M  Fernandez Rodriguez  
 
Reviewer ’s report:  
 
This is an interesting manuscript addressing the impact of bile microbial isolates on outcomes of 
163 patients with advanced bile obstructive malignancy undergoing palliative ERCP draining 
procedures. They concluded that infection with multi -resistant microorganis ms and inflammation 
biomarkers negativelynimpcted on clinical outcomes. I would invite the authors to further clarify 
the following issues:  
 
 
Major:  
 
1. How were patients recruited;  consecutively vs randomly?  Methods of bile samples 
collection should be de scribed.  
 
2. Insufficient bile drainage might predispose to persistent infection and conceivable to 
multi -resistant strains. Please, introduce in the multivariate analysis drainage as a 
covariate (Eg complete vs non -complete)  
 
3. Previous ERCP was associate d to fungi bile colonisation;  in turn it might have been 
introduced a lenght -time bias as these patients are likely to have longer  evolution of their 
malignancy.  
 
4. It is unclear to me wether bile infection might have delayed initiation of chemotherapy. If 
so, have you analysed the impact on survival of the variable date of diagnosis -date of 
systemic chemotherapy?  
 
Are the methods appropriate and well de scribed?  
If not, please specify what is required in your comments to the authors.  
 
Unable to assess  
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
No 
 
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 re commended, 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, e ither 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 relatin g 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 i nterests' 
below.  If your reply is yes to any, please give details below.  
 
I have nothing to disclose regarding this manuscript.  
 
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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 no t be published.  
 
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