Review for 10.1186/s12876-016-0444-1 (2016)

Reviewer’s report 
Title:  Confinement to the intrapancreatic bile duct is in dependently associated with a better 
prognosis in extrahepatic cholangiocarcinoma 
 
Version:  0 Date:  13 Dec 2015 
 
Reviewer:  Muhammed Sherid 
 
Reviewer's report: 
Cholangiocarcinoma is a rare GI cancer, thus having  a study with 110 patients considers large 
size for this disease. It is an interesting study. However there are a few things I want to mention.  
Firstly, even the authors are talking about Cholang icarcinoma but they never mentioned it. If 
they are talking about something different they sho uld mention it clearly. The term bile duct 
cancer is broad. If not all these cases are cholang iocarcinoma, it should be mentioned the 
histopathology for all cases.  
Secondly, subtitles in the result section as questi ons are never impressive and it is better to put 
real subtitles and the readers who are interested w ill find out what the questions are. So o need to 
put subtitles as questions.  
Thirdly, in the result section, authors did not giv e any p values in the text which I think they are 
very important when you try to tell the differences . Some important numbers and p values are 
crucial to be mentioned in the text, but on same ta ken, the text should filled with numbers. So 
you have put some important number in the text but not all.  
I think if these changes made, the study will be wo rthwhile to be published this study in BMC 
Gastroentrology journal. 
 
Are the methods appropriate and well described? 
If not, please specify what is required in your com ments 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 t he data shown 
If not, please explain in your comments to the auth ors. 
Yes 
Are you able to assess any statistics in the manusc ript 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 manu script: 
Acceptable 
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