Prevalence of genital human papillomavirus DNA in a sample of senior school-aged women in the Australian Capital Territory

The impact of smoking on HPV infection and the development of anogenital warts

PURPOSE

The worldwide prevalence of human papillomavirus (HPV) infection is estimated at 9-13 %. Persistent infection can lead to the development of malignant and nonmalignant diseases. Low-risk HPV types are mostly associated with benign lesions such as anogenital warts. In the present systematic review, we examined the impact of smoking on HPV infection and the development of anogenital warts, respectively.

METHODS

A systematic literature search was performed using MEDLINE database for peer-reviewed articles published from January 01, 1985 to November 30, 2013. Pooled rates of HPV prevalence were compared using the χ (2) test.

RESULTS

In both genders, smoking is associated with higher incidence and prevalence rates for HPV infection, whereas the latter responds to a dose-effect relationship. The overall HPV prevalence for smoking patients was 48.2 versus 37. 5 % for nonsmoking patients (p < 0.001) (odds ratio (OR) = 1.5, 95 % confidence interval (CI) 1.4-1.7). Smoking does also increase persistence rates for high-risk HPV infection, while this correlation is debatable for low-risk HPV. The incidence and recurrence rates of anogenital warts are significantly increased in smokers.

CONCLUSIONS

Most current data demonstrate an association between smoking, increased anogenital HPV infection, and development of anogenital warts. These data add to the long list of reasons for making smoking cessation a keystone of patient health.

Alcohol drinking in never users of tobacco, cigarette smoking in never drinkers, and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

BACKGROUND

At least 75% of head and neck cancers are attributable to a combination of cigarette smoking and alcohol drinking. A precise understanding of the independent association of each of these factors in the absence of the other with the risk of head and neck cancer is needed to elucidate mechanisms of head and neck carcinogenesis and to assess the efficacy of interventions aimed at controlling either risk factor.

METHODS

We examined the extent to which head and neck cancer is associated with cigarette smoking among never drinkers and with alcohol drinking among never users of tobacco. We pooled individual-level data from 15 case-control studies that included 10,244 head and neck cancer case subjects and 15,227 control subjects, of whom 1072 case subjects and 5775 control subjects were never users of tobacco and 1598 case subjects and 4051 control subjects were never drinkers of alcohol. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models. All statistical tests were two-sided.

RESULTS

Among never drinkers, cigarette smoking was associated with an increased risk of head and neck cancer (OR for ever versus never smoking = 2.13, 95% CI = 1.52 to 2.98), and there were clear dose-response relationships for the frequency, duration, and number of pack-years of cigarette smoking. Approximately 24% (95% CI = 16% to 31%) of head and neck cancer cases among nondrinkers in this study would have been prevented if these individuals had not smoked cigarettes. Among never users of tobacco, alcohol consumption was associated with an increased risk of head and neck cancer only when alcohol was consumed at high frequency (OR for three or more drinks per day versus never drinking = 2.04, 95% CI = 1.29 to 3.21). The association with high-frequency alcohol intake was limited to cancers of the oropharynx/hypopharynx and larynx.

CONCLUSIONS

Our results represent the most precise estimates available of the independent association of each of the two main risk factors of head and neck cancer, and they exemplify the strengths of large-scale consortia in cancer epidemiology.

Human papillomavirus vaccines: challenges to implementation

Clinical trials for prophylactic human papillomavirus (HPV) vaccines have shown overwhelmingly positive results. It is expected that with good coverage of the vaccine, 70% of cervical cancers will be prevented, as will a proportion of other HPV-related anogenital diseases. Issues that will require careful consideration will include: whether males and females should be vaccinated; the durability of the immune response; the proportion of attributable disease to the HPV types targetted by the vaccines; and accessibility and cost of the vaccine. Central to an effective vaccination programme will be clear, concise and consistent educative messages regarding HPV not only to the lay public, but also the medical profession.