Involuntary smoking and head and neck cancer risk: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Head and neck cancer in a developing country: a population-based perspective across 8 years

Head and neck cancer (HNC) has been studied in different regions of the world but little is known about its incidence patterns in the Middle East and Egypt. In this study from Egypt's only population-based registry, we analyzed data from 1999 to 2006, to estimate incidence, incidence rate ratios (IRRs) and 95% confidence intervals (CIs) categorized by age, district and subsites. Overall urban incidence of HNC was twice or more that of rural incidence for both males (IRR=2.59; 95% CI=2.26, 2.97) and females (IRR=2.00; 95% CI=1.64, 2.43). Highest urban-rural difference for males was seen in 40-49years (IRR=2.79; 95% CI=1.92, 4.05) and for females in 30-39years (IRR=2.94; 95% CI=1.60, 5.40). Among subsites, highest incidence among males was for larynx (1.53/10(5)) and among females for gum and mouth (0.48/10(5)). Maximum urban-rural difference in males was for paranasal sinus (IRR=4.66; 95% CI=1.88, 11.54) and in females for lip (IRR=8.91; 95% CI=1.89, 41.98). The study underscores the patterns of HNC incidence in Egypt while indicating the need for future analytical studies investigating specific risk factors of HNC in this population.

Tabagismo e câncer no Brasil: evidências e perspectivas

Neste artigo analisa-se a tendência temporal da prevalência do tabagismo no Brasil, bem como as assimetrias da prevalência de acordo com as regiões do país, a idade, o gênero e o nível socioeconômico da população. Desde o estabelecimento da relação entre tabagismo e câncer de pulmão há 60 anos, o número de tumores malignos com evidências de associação causal com o tabagismo ascendeu a vinte. O declínio da prevalência do tabagismo na população brasileira tem sido constante desde o final da década de 80. Até 2003, foi mais intenso entre os homens. A partir daquele ano, a queda tornou-se mais pronunciada entre as mulheres. As mais altas prevalências de tabagismo encontram-se no Sudeste e Sul, as duas regiões com maiores incidências de neoplasias estritamente relacionadas ao tabaco (cavidade oral, esôfago e pulmão). A exposição ambiental à fumaça do tabaco também foi examinada considerando-se os efeitos para os adultos não fumantes, que apresentam maior risco de tumores de pulmão, laringe e faringe, e entre crianças de pais fumantes, suscetíveis ao risco de hepatoblastoma e leucemia linfocítica aguda. Apesar do incontestável sucesso da política de controle do tabagismo no país, as ações de prevenção devem considerar que as parcelas da população com piores condições socioeconômicas e com baixo nível educacional são as que apresentam taxas mais altas de prevalência de tabagismo. Dentro destes segmentos populacionais os adolescentes representam uma prioridade.

Active and involuntary tobacco smoking and upper aerodigestive tract cancer risks in a multicenter case-control study

INTRODUCTION

Several important issues for the established association between tobacco smoking and upper aerodigestive tract (UADT) cancer risks include the associations with smoking by cancer subsite, by type of tobacco, and among never alcohol drinkers and the associations with involuntary smoking among nonsmokers. Our aim was to examine these specific issues in a large-scale case-control study in Europe.

METHODS

Analysis was done on 2,103 UADT squamous cell carcinoma cases and 2,221 controls in the Alcohol-Related Cancers and Genetic Susceptibility in Europe project, a multicenter case-control study in 10 European countries. Unconditional logistic regression was done to obtain odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Compared with never tobacco smoking, current smoking was associated with UADT cancer risks (OR, 6.72; 95% CI, 5.45-8.30 for overall; OR, 5.83; 95% CI, 4.50-7.54 for oral cavity and oropharynx; OR, 12.19; 95% CI, 8.29-17.92 for hypopharynx and larynx; and OR, 4.17; 95% CI, 2.45-7.10 for esophagus). Among never drinkers, dose-response relationships with tobacco smoking pack-years were observed for hypopharyngeal and laryngeal cancers (P(trend) = 0.010) but not for oral cavity and oropharyngeal cancers (P(trend) = 0.282). Among never smokers, ever exposure to involuntary smoking was associated with an increased risk of UADT cancers (OR, 1.60; 95% CI, 1.04-2.46).

CONCLUSION

Our results corroborate that tobacco smoking may play a stronger role in the development of hypopharyngeal and laryngeal cancers than that of oral cavity and oropharyngeal cancers among never drinkers and that involuntary smoking is an important risk factor for UADT cancers. Public health interventions to reduce involuntary smoking exposure could help reduce UADT cancer incidence.

Recent changes in the epidemiology of head and neck cancer

PURPOSE OF REVIEW

To review the most recent epidemiological studies on head and neck cancer and changes in knowledge about risk factors. The main review concerned the squamous cell carcinoma of the oral cavity, oropharynx, larynx and hypopharynx.

RECENT FINDINGS

Overall, the incidence of head and neck cancer is increasing in women, whereas it is decreasing in men. Chewing tobacco is a newly recognized risk factor of great public health concern. Human papillomavirus infection has been found to be a factor of good prognosis for oral cavity and oropharynx squamous cell cancer. The role of tobacco smoking and alcohol in the genesis of this cancer has been reinforced.

SUMMARY

The presence or absence of human papillomavirus in patients with squamous cell carcinoma of the head and neck is a new parameter for prediction of long-term outcome of cancer of the oral cavity and of the oropharynx. Head and neck cancer among women in developing countries should deserve more attention, as the mortality rates appear to be higher than those of women in developed countries. For never smokers and never drinkers, more research needs to be done to identify their risk factor patterns.