Reviewer ’s report  
 
Title: Oral contraceptive and breast cancer: do benefits outweigh the risks? a Case - control 
study from Jordan  
 
Version: 0 Date: 31 Aug 2018  
 
Reviewer: Benjamin Calhoun  
 
Reviewer's report:  
 
This study is a reasonable initial step in providing data on oral contraceptive (OC) use and breast 
cancer risk in women in the Middle East. the sample size is small but the authors correctly 
suggest that subsequent larger studies should be conducted to ad dress unanswered questions. 
There are significant differences between the cases and controls for several breast cancer risk 
factors but the authors clearly state this in the Results. It should be noted that cases and controls 
showed significant differences  in OC use and duration - is this a confounding factor? The 
differences ion pregnancy, menopausal status and cancer history are also remarkable and must be 
accounted for in the Discussion.  If not, please explain why not. What needs to be clear is the 
independent contribution to breast cancer risk that can be attributed to OC use. It's a little 
surprising that duration of OC use did not appear to be significant in this study. There needs to 
be some explanation for this. Could this be related to sample size and/or selection bias? Were the 
controls also form April November 2017 time period? How were controls selected? Do the 
authors have any information on the formulation of the OCs - were the estrogen/progestin doses 
the same or similar for all of the women? Table 2 only shows OC formulation data for 81 
patients. Does Table 3 show that duration of OC was significant with cases having longer 
duration? Approximately 36% of cases (versus 0% of controls) had Tamoxifen - was this part of 
their cancer treatment?  
Are the methods appropriate and well described?  
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 a uthors.  
 
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 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 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, 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 f or 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 declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be included  
on my report to the authors and, if the manuscript is accepted for publication, my named report  
including any attachments I upload will be posted on the website along with the authors'  
responses. I agree for my report to be made available under an Open Access Creative Commons  
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments  
which I do not wish to be included in my named report can be included as confidential comments  
to the editors, which will not be published.  
 
I agree to the open pee r review policy of the journal