Published online Aug 10, 2013. doi: 10.5317/wjog.v2.i3.53
Revised: April 9, 2013
Accepted: May 16, 2013
Published online: August 10, 2013
Processing time: 118 Days and 17.4 Hours
AIM: To investigate whether smoking is associated with human papilloma virus (HPV) infection.
METHODS: HPV infection is considered to be a necessary condition for cervical cancer development. The study population included 1291 women, aged 25-55 years, attending cervical cancer screening. All women had a Papanicolaou (Pap) test, with liquid-based cytology (Thinprep®), an HPV-DNA test and an evaluation of smoking habits. The COBAS® 4800 system was used for HPV-DNA testing, enabling identification of the following high-risk HPV (hrHPV)-types: each of HPVs 16 and 18 separately, and HPVs 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68 as a cocktail. The evaluation of smoking habits was assessed using the smoking intensity index (SII), a variable formed as the product of cigarettes consumed per day by the days (years × 365) that a woman was a smoker, divided by 1000.
RESULTS: There were 136 smokers among 238 women tested positive for hrHPV-types (HPVs 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and/or 68), and 463 smokers among 1053 hrHPV-negative women (OR = 1.7, P < 0.001). This association was attributed to the youngest age group of women, aged 25-34 years (OR = 2.3, P < 0.001), while there was no association in other age groups. The intensity of smoking (increasing SII) showed no statistically significant association with hrHPV infection. Cervical infection with HPV 16 and/or HPV 18 was also not associated with age or smoking habits. Finally, no association was found between Pap test status and smoking habits or smoking intensity.
CONCLUSION: Smoking appears to be associated with hrHPV infection of the uterine cervix, particularly in younger women. Further studies should investigate whether this association is based on causality and evaluate the role of other possible co-factors.
Core tip: Human papilloma virus (HPV) infection is a prerequisite for cervical cancer development. We investigated whether smoking can influence the course of HPV infection, in 1291 women attending cervical cancer screening. Smoking appeared to be associated with high-risk HPV (hrHPV) infection of the uterine cervix, particularly in younger women, aged 25-34 years. In addition, women in this younger age group with a negative Pap test were more likely to have hrHPV infection if they were smokers than if they did not smoke. Further studies should investigate whether this association is based on causality and evaluate the role of other possible co-factors.