Lower red blood cell folate enhances the HPV-16-associated risk of cervical intraepithelial neoplasia.
OBJECTIVE
We previously reported that higher circulating concentrations of folate are independently associated with a lower likelihood of becoming positive for high-risk human papillomaviruses (HR-HPVs) and of having a persistent HR-HPV infection and a greater likelihood of becoming HR-HPV negative (Cancer Res 2004;64:8788-93). In the present study conducted in the same study population, we tested whether circulating folate concentrations modify the risk of cervical intraepithelial neoplasia (CIN) > or =2 associated with specific types of HR-HPV.


METHODS
Multiple logistic regression models were used to assess associations (odds ratio with 95% confidence intervals) across HR-HPV, folate, and rigorously reviewed cervical histology of each subject.


RESULTS
HPV-16-positive women with low red blood cell folate were significantly more likely to be diagnosed with CIN > or =2 than were HPV-16-negative women with higher red blood cell folate (odds ratio 9, 95% confidence interval 3.3-24.8).


CONCLUSIONS
To our knowledge, this is the first study reporting an independent association of folate with risk of having CIN > or =2 in a population tested extensively for HR-HPV and CIN that also adequately controlled for several other micronutrients and known risk factors for CIN. Our findings suggest that improving the folate status in HR-HPV-infected women may reduce the risk of CIN and thus the risk of cervical cancer. Folate supplementation should be tested as a means of reducing the risk of developing CIN > or =2 in women exposed to HR-HPV, especially HPV-16.
Piyathilake
Chandrika J
CJ
Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA.
Macaluso
Maurizio
M
Brill
Ilene
I
Heimburger
Douglas C
DC
Partridge
Edward E
EE
D000328:Adult; D016001:Confidence Intervals; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005492:Folic Acid / Q000032:analysis / Q000378:metabolism*; D052162:Human papillomavirus 16; D006801:Humans; D016015:Logistic Models; D016017:Odds Ratio; D030361:Papillomavirus Infections / Q000097:blood / Q000453:epidemiology*; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D002578:Uterine Cervical Dysplasia / Q000097:blood / Q000453:epidemiology* / Q000473:pathology / Q000821:virology
D005492:Folic Acid