Red blood cell folate, high-risk human papillomavirus risk and cervical intraepithelial neoplasia development: A large Chinese community-based cohort study of cervical screening.

Abstract

10547 Background: Although low folate status has been implicated in cervical carcinogenesis, large-scale population-based prospective cohort studies controlling for high-risk types of human papillomavirus (hrHPV) infection are lacking. The aim of this study is to evaluate the associations of red blood cell (RBC) folate, hrHPV infection risk and cervical intraepithelial neoplasia (CIN) development. Methods: In this prospective, population-based cohort study, we analyzed the cross-sectional data of 2304 women from a large cervical cancer screening program of 40,000 women aged 19-65 years in the Chinese rural area from 2014-2015. We conducted a nested case-control study including 35 CIN1 progression cases and 105 CIN1 regression controls. A logistic regression model was used to evaluate the associations of RBC folate and hrHPV infection risk and CIN1 development. Results: The median RBC folate concentration decreased gradually with cervical lesion severity. The risks of CIN 1 and CIN2 or worse (CIN 2+) in the 1st quartile of RBC folate concentration were significantly higher than those in the 4th quartile (Odds Ratio [OR], 2.27; 95% confidence interval [CI], 1.71-3.01 and OR, 2.33; 95% CI,1.52-3.56; respectively). We did not observe a significant relationship between hrHPV infection and CIN1 risk in the unadjusted and adjusted models, however, a statistically significant association was observed for CIN2+. Interestingly, RBC folate concentration was not associated with hrHPV infection among women with CIN1 or CIN2+. After full adjustment for potential confounders, a highly significant inverse linear relation between RBC folate concentration and CIN2+ was observed ( P-overall＜0.001, P-nonlinearity = 0.969). We further observed a positive additive interaction between RBC folate concentration and hrHPV infection on the risk of CIN2+ ( P-interaction＜0.01). Moreover, during the 21-month follow-up, CIN1 progression risk was significantly higher in the lowest RBC folate quartile (1st quartile compared with 4th quartile: OR, 3.86; 95% CI,1.01-14.76). Conclusions: Our findings indicates that RBC folate is inversely associated with the risk of higher-grade CIN and CIN1 progression in the Chinese rural population, either with or without hrHPV infection. Therefore, improving folate status has the potential to prevent higher-grade CIN and cervical cancer among women in the areas without mandatory folic acid food fortification. Clinical trial information: ChiCTR-ROC-15006479 .