• 3/4/2008
  • web-based article
  • Salvatore Vaccarella et al.
  • International Journal of Epidemiology, doi:10.1093

Background:
Smoking increases the risk of squamous-cell carcinoma of the cervix, but it is not clear whether smoking increases the risk of acquisition or persistence of human papillomavirus (HPV) infection.

Methods:
Information on smoking was collected from 10 areas in four continents among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was performed using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) of being HPV-positive by smoking habits, adjusted for age and lifetime number of sexual partners.

Results:
Ten thousand five hundred and seventy-seven women (mean age 41.4 years) were included. Among current smokers, the risk of being HPV-positive increased with smoking intensity, after allowing for lifetime number of sexual partners: ORs for <5, 5–14 and 15 cigarettes per day were 1.21 (95% CI 0.95–1.54), 1.39 (95% CI 1.04–1.87) and 2.01 (95% CI 1.32–3.08), respectively, as compared with never-smokers. The risk among former smokers (OR = 0.95, 95% CI 0.73–1.23) was similar to that among never-smokers. Analyses stratified by lifetime number of sexual partners showed a significant trend in risk only for women with one lifetime sexual partner.

Conclusions:
Our study suggests that current, though not former, smoking is associated with an increased prevalence of HPV, after allowance for sexual covariates. Among current smokers, HPV prevalence increased with smoking intensity, but a clear dose–response relationship was exclusively seen among women who declared one lifetime sexual partner.

Authors:
Salvatore Vaccarella1, Rolando Herrero2, Peter J F Snijders3, Min Dai1, Jaiye O Thomas4, Nguyen Trong Hieu5, Catterina Ferreccio6, Elena Matos7, Hector Posso8, Silvia de Sanjosé9, Hai Rim Shin10, Sukhon Sukvirach11, Eduardo Lazcano-Ponce12, Nubia Muñoz8, Chris J L M Meijer3, Silvia Franceschi1 and the IARC HPV Prevalence Surveys (IHPS) Study Group

Authors’ affiliations’:
1 International Agency for Research on Cancer, Lyon, France.
2 Proyecto Epidemiológico Guanacaste, Fundación INCIENSA, San José, Costa Rica.
3 VU Medical Center, Amsterdam, The Netherlands.
4 College of Medicine, University of Ibadan, Ibadan, Nigeria.
5 Neonatology Department, Hung Vuong Hospital, Ho Chi Minh City, Vietnam.
6 Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
7 Instituto de Oncología Angel H. Roffo, Universidad de Buenos Aires, Buenos Aires, Argentina.
8 Instituto Nacional de Cancerología, Bogota, Colombia.
9 Servei d’Epidemiologia i Registre del Cancer Institut Català d’Oncologia, L’Hospitalet del Llobregat, Barcelona, Spain.
10 Research Institute, National Cancer Centre, Goyang, Korea.
11 Research Division, National Cancer Institute, Bangkok, Thailand.
12 Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico.