Syrjänen K, Shabalova I, Petrovichev N, Kozachenko V, Zakharova T, Pajanidi J, Podistov J, Chemeris G, Sozaeva L, Lipova E, Tsidaeva I, Ivanchenko O, Pshepurko A, Zakharenko S, Nerovjna R, Kljukina L, Erokhina O, Branovskaja M, Nikitina M, Grunberga V, Grunberg A, Juschenko A, Santopietro R, Cintorino M, Tosi P, Syrjänen S. Smoking is an independent risk factor for oncogenic human papillomavirus (HPV) infections but not for high-grade CIN.
Eur J Epidemiol 2007;
22:723-35. [PMID:
17828436 DOI:
10.1007/s10654-007-9180-8]
[Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 08/27/2007] [Indexed: 11/27/2022]
Abstract
BACKGROUND
Recent evidence implicates smoking as a risk factor for cervical cancer (CC), but the confounding from high-risk human papillomavirus (HPV) infections is not clear.
OBJECTIVES
To analyse the role of smoking as an independent predictor of CIN2+ and HR-HPV infections in a population-based prospective (NIS, New Independent States of former Soviet Union) cohort study.
STUDY DESIGN AND METHODS
A cohort of 3,187 women was stratified into three groups according to their smoking status: (i) women who never smoked; (ii) those smoking in the past; and (iii) women who are current smokers. These groups were analysed for predictors of (a) HR-HPV; (b) high-grade CIN, and (c) outcome of HR-HPV infections and cytological abnormalities during prospective follow-up (n = 854).
RESULTS
The three groups were significantly different in all major indicators or risk sexual behaviour (or history) implicating strong confounding. There was no increase in HSIL/LSIL/ASC-US cytology or CIN1+/CIN2+/CIN3+ among current smokers. Only few predictors of HR-HPV and CIN2+ were common to all three groups, indicating strong interference of the smoking status. There was no difference in outcomes of cervical disease or HR-HPV infections between the three groups. In multivariate model, being current smoker was one of the five independent predictors of HR-HPV (P = 0.014), with adjusted OR = 1.52 (95%CI 1.09-2.14). In addition to age, HR-HPV was the only independent predictor of CIN2+ in multivariate model (OR = 14.8; 95%CI 1.72-127.31).
CONCLUSIONS
These data indicate that cigarette smoking is not an independent risk factor of CIN2+, but the increased risk ascribed to smoking is mediated by acquisition of HR-HPV, of which current smoking was an independent predictor in multivariate model.
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