title: Risk for cervical intraepithelial neoplasia grade 3 or worse in relation to smoking among women with persistent human papillomavirus infection.
abstract: BACKGROUND
  Smoking has been associated with cervical cancer. We examined whether smoking increases the risk for high-grade cervical lesions in women with high-risk human papillomavirus (HPV) infection.
  
  
  METHODS
  In a population-based cohort study, 8,656 women underwent a structured interview, and subsequently cervical cells were obtained for HPV DNA testing. Women with high-risk HPV infection and no prevalent cervical disease at baseline (n = 1,353) were followed through the Pathology Data Bank for cervical lesions for up to 13 years. Separate analyses of women with persistent high-risk HPV infection (n = 312) were also conducted. HRs for a diagnosis of cervical intraepithelial neoplasia grade 3 or worse/high-grade squamous intraepithelial lesions or worse (CIN3+) and the corresponding 95% confidence intervals (CI) were calculated in the two groups.
  
  
  RESULTS
  Among high-risk HPV-positive women, an increased risk for CIN3+ was associated with long-term smoking (≥10 years) and heavy smoking (≥20 cigarettes/d). In the subgroup of women with persistent HPV infection, heavy smoking was also associated with a statistically significantly higher risk for CIN3+ than never smoking (HR, 1.85; 95% CI, 1.05-3.22, adjusted for length of schooling, parity, and HPV type at baseline). The average number of cervical cytology screening tests per year during follow-up did not explain the differences in risk in relation to smoking (P = 0.4).
  
  
  CONCLUSIONS
  Smoking is associated with an increased risk for subsequent high-grade cervical lesions in women with persistent high-risk HPV infection.
  
  
  CONCLUSIONS
  Our study adds to the understanding of the role of smoking in the natural history of HPV and cervical carcinogenesis.
authors.affiliation: Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Kirsten Egebjerg
authors.initials: KE
authors.lastname: Jensen
authors.forename: Sven
authors.initials: S
authors.lastname: Schmiedel
authors.forename: Kirsten
authors.initials: K
authors.lastname: Frederiksen
authors.forename: Bodil
authors.initials: B
authors.lastname: Norrild
authors.forename: Thomas
authors.initials: T
authors.lastname: Iftner
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Kjær
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D060787:Neoplasm Grading; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000821:virology; D055815:Young Adult; D002578:Uterine Cervical Dysplasia / Q000453:epidemiology* / Q000473:pathology / Q000821:virology