Chlamydia trachomatis infection and risk of cervical intraepithelial neoplasia

Sex Transm Infect. 2011 Aug;87(5):372-6. doi: 10.1136/sti.2010.044354. Epub 2011 Apr 6.

Abstract

Objectives: High-risk human papillomavirus (hrHPV) is the primary cause of cervical cancer. As Chlamydia trachomatis is also linked to cervical cancer, its role as a potential co-factor in the development of cervical intraepithelial neoplasia (CIN) grade 2 or higher was examined.

Methods: The placebo arms of two large, multinational, clinical trials of an HPV6/11/16/18 vaccine were combined. A total of 8441 healthy women aged 15-26 years underwent cervicovaginal cytology (Papanicolaou (Pap) testing) sampling and C trachomatis testing at day 1 and every 12 months thereafter for up to 4 years. Protocol-specified guidelines were used to triage participants with Pap abnormalities to colposcopy and definitive therapy. The main outcome measured was CIN.

Results: At baseline, 2629 (31.1%) tested positive for hrHPV DNA and 354 (4.2%) tested positive for C trachomatis. Among those with HPV16/18 infection (n = 965; 11.4%) or without HPV16/18 infection (n = 7382, 87.5%), the hazard ratios (HRs) associated with development of any CIN grade 2 according to baseline C trachomatis status were 1.82 (95% CI: 1.06 to 3.14) and 1.74 (95% CI 1.05 to 2.90), respectively. The results were comparable when only the 12 most common hrHPV infections were considered, but the excess risk disappeared when the outcome was expanded to include CIN grade 3 or worse.

Conclusion: Further studies based on larger cohorts with longitudinal follow-up in relation to the C trachomatis acquisition and a thorough evaluation of temporal relationships of infections with hrHPV types, C trachomatis and cervical neoplasia are needed to demonstrate whether and how in some situations C trachomatis sets the stage for cervical carcinogenesis. Trial registration NCT00092521 and NCT00092534.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Chlamydia Infections / complications*
  • Chlamydia Infections / diagnosis
  • Coitus
  • DNA, Viral
  • Disease Progression
  • Early Detection of Cancer
  • Female
  • Humans
  • Papillomaviridae / isolation & purification
  • Papillomavirus Infections / complications*
  • Papillomavirus Infections / diagnosis
  • Risk Factors
  • Sexual Partners
  • Uterine Cervical Dysplasia / virology*
  • Uterine Cervical Neoplasms / virology*
  • Young Adult

Substances

  • DNA, Viral

Associated data

  • ClinicalTrials.gov/NCT00092521
  • ClinicalTrials.gov/NCT00092534