Reviewer ’s report  
 
Title: Reproductive Risk Factors Associated with Breast Cancer in Wome n in Bangui: A Case -
Control Study  
 
Version: 1 Date: 12 Nov 2016  
 
Reviewer: J Hulme  
 
Reviewer's report:  
 
Overall, a native English speaker is needed to edit the grammatical errors, which can affect our 
interpretation of the results.  
What was the rational for limiting the study to reproductive factors, as opposed to all known  risk 
factors for breast Ca?  
Throughout the paper, there seems to be lack of clarity communicated about the known 
modifiable and non -modifiable risk factors for breast Ca. This is an example for patients -  but 
highlights that quite a bit is known globall y and this should be stated clearly in the paper.  
http://www.breastcancer.org/symptoms/understand_bc/risk/factors   
 
Page 5.  
Background:  
Line 8: As 'BC' is not commonly used to denote breast cancer, and confused for before Christ, I 
wonder if breast C A would be better.  
Line 21: Clean this.  
 'considerable variations in geographical, racial and ethnic factors, in addition to environmental 
and genetic factors [5].  
Line 26: Define 'lifestyle'. Do you mean obesity and alcohol use? Please state this if s o.  
Line 34 -35 - stay consistent in present tense (history of abortion and oral contraceptive use is 
also…)  
Line 45. Young age at first live birth is not part of African culture as much as it is part of the 
reality for many women who lack access to family planning in poor and rich country settings. 
Child marriage is also a reality of women living in poor, often rural traditional societies. But 
calling this 'African culture' does a disservice to the complexities of the realities of women. 
Please re -write this with a native English writer's help.  
Line 48 To answer the question of why there is an increase in incid ence in recent decades, there 
are a many theories in high resource settings, notably the increase in obesity, and over diagnosis 
caused by screening programs and care seeking for benign breast disease caused by breast cancer 
awareness and propaganda. Quote  these studies.  In SSA, patients likely never used to present 
with breast Ca and died at home of its complications.  
 
Page 6  
Grammatical changes: Line 10: As part of a larger effort to inform the Ministry of Health of the 
characteristics and possible int erventiosn to prevent breast cancer, this case -control study ….  
Line 10. Rarely do case -control studies looking at the reproductive factors associated with a 
disease actually assist in developing strategies for early detection of breast cancer. Factors 
including alcohol consumption and obesity have helped contribute to arguments for broader 
population health interventions. Be careful not to overstate the significance of this.  
 
Page 7  
Line 33: reproductive factors were no the only factors you included as  variables.  
Line 43: being a housewife and raising children is a function. Instead, to recognize women's 
unpaid work as work, perhaps try "occupation was classified as a homemaker or paid 
employment outside of the home".  
List 44 Economic status was defi ned… etc.  
Fix the grammatical errors in this paragraph.  
 
Page 9  
Line 4: Overall, there are major differences between your controls and cases in terms of who 
these women are. Because of this, it is difficult to interpret your findings of 'reproductive 
factors'.  
Line 11: there is no reason to calculated the differencein mean age given these were age match 
controls. Delete? This is the only factor your matched for.  
Line 20: Can delete information which is redundant from the tbale  
Line 40: if early pa rity and breastfeeding are protective, how do you reconcile that married 
women were at higher risk of breast Ca? Is it because marriage is a proxy for lower 
socioeconomic status? Address this in the discussion.  
Line 44: Similarly, does employment and education and city living protect women from breast 
Ca, or is all a reflection of selection bias for women who presented very late with end stage 
cancer, and were matched with women who presented with 'other patholog ies' to the national lab 
who, given that they are still alive might have presented for benign conditions and therefore are 
more likely to be educated and wealthy? These are the severe limitations of this study.  
 
Results:  
Hormonal contraceptive use was p rotective (aOR = 0.62). Do you think this confounding for 
high SES? Why is this different than other studies?  
 
Discussion:  
Is the mean age of the 522 women in the study of 45 years of age significantly younger than 
those studied in other contexts? This i s quite young. Risk factors for BRCA -linked breast cancer 
is quite different from non BRCA -related breast cancer. This is a case -control study, so although 
there were age -matched controls, the results may not be comparable to other case -control studies 
where the mean age of participants are significantly higher.  
Line 52: abortion and parity do not necessarily increase the risk of breast cancer. They are 
associated in your study with increased odds of breast Ca.  
Line 54: Women are not victims of abortion s. They have abortions.  
Line 59: late age at first menarche  
Page 10 line 2: Try 'were significantly associated with lower odds of have breast cancer in this 
study.'  
Page 10  - Discussion   
Line 45 -60. Rethink this issue. Your controls  - who did not h ave breast cancer - were more 
educated women than your cases, who presented with symptomatic disease. Therefore, you will 
only find an associated between education and breast cancer. Line 58 is insulting and medically 
incorrect - please delete. Certainly m ore educated women will likely present earlier with their 
disease, but once breast Ca is clinically symptomatic in CAR, as is in the case with most parts of 
the world, it is often untreatable.  
Page 11 Lines 6 -45. Same issues as above. Address recall bias  inherent in case -control studies  
Line 49 -58. Again, what if your controls are the real issue?  
 
Page 12: Line 4  
Page 12 Line 33 -43  
These relationships are more reasonable to discuss as you state the 'odds of having breast Ca 
were higher" among when that have had an abortion. Change the language  in the other sections 
accordingly.  
Page 13 line 28. Discuss this. If nulliparity is a ris k factor (which it is in other studies) why do 
you postulate that hormonal contraceptives were protective?  
 
How does this compare to the literature?  
1. Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormonal 
contraceptives: col laborative reanalysis of individual data on 53,297 women with breast 
cancer and 100,239 women without breast cancer from 54 epidemiological studies. Lancet 
1996; 347(9017):1713 -1727. [PubMed Abstract]  
Line 37 -52: Fix grammar. Use terms like recall bias. P lease consider the limitations of the case 
control study.  
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 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 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:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing in terests, 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 t he 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 th e 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 y ou 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 att achments 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 peer review policy of the journal