METHODS: Using HPV serology as a marker of HPV-related cancer, we examined the interaction between smoking and HPV16 in 459 oropharyngeal (and 1445 oral cavity and laryngeal) cancer patients and 3024 control participants from two large European multi-centre studies. Odds ratios and credible intervals [CrI], adjusted for potential confounders, were estimated using Bayesian logistic regression.
RESULTS: Both smoking [odds ratio (OR [CrI]: 6.82 [4.52, 10.29]) and HPV seropositivity (OR [CrI]: 235.69 [99.95, 555.74]) were independently associated with oropharyngeal cancer. The joint association of smoking and HPV seropositivity was consistent with that expected on the additive scale (synergy index [CrI]: 1.32 [0.51, 3.45]), suggesting they act as independent risk factors for oropharyngeal cancer.
CONCLUSIONS: Smoking was consistently associated with increase in oropharyngeal cancer risk in models stratified by HPV16 seropositivity. In addition, we report that the prevalence of oropharyngeal cancer increases with smoking for both HPV16-positive and HPV16-negative persons. The impact of smoking on HPV16-positive oropharyngeal cancer highlights the continued need for smoking cessation programmes for primary prevention of head and neck cancer.
IMPORTANCE: This collaborative international study defined the global heterogeneity of HPV11 and established the largest collection of globally circulating HPV11 genomic variants to date. Thirty novel complete HPV11 genomes were determined and submitted to the available sequence repositories. Global phylogenetic analysis revealed two HPV11 variant lineages and four sublineages. The HPV11 (sub)lineage-specific SNPs and the representative region identified within the partial genomic region E2/noncoding region 2 (NCR2) will enable the simpler identification and comparison of HPV11 variants worldwide. This study provides an important knowledge base for HPV11 for future studies in HPV epidemiology, evolution, pathogenicity, prevention, and molecular assay development.
MATERIALS AND METHODS: This was an experimental before and after study performed between October 2014 and March 2015. Five hundred and eighty students were randomly assigned into intervention and control groups. All were required to complete both pre-intervention and post-intervention questionnaires. Those in the intervention group were given an information leaflet to read before answering the post-intervention questionnaire.
RESULTS: Almost half (48.3%) of the students had poor knowledge, with a score less than 5, and only 51 (8.8%) exhibited good knowledge, with a score of 11 and above. After educational intervention, the number of students with poor knowledge was reduced to 177 (29.3%) and the number of students who exhibited good knowledge increased to 148 (25.5%). Students from the intervention group demonstrated significant higher total scores in knowledge regarding 'HPV infection and cervical cancer' (p=0.000) and 'HPV vaccination and cervical cancer prevention' (p=0.000) during post-intervention as compared to the control group.
CONCLUSIONS: Knowledge on HPV infection and vaccination is low among pre-university students. Educational intervention in the form of information leaflets appears effective in creating awareness and improving knowledge.