Fraction of head and neck cancer attributable to tobacco and alcohol in cities of three Brazilian regions

Objectives: To estimate the fraction of head and neck cancer (HNC) attributable to tobacco and alcohol in cities in the Midwest, Southeast and South regions of Brazil. Methods: Case-control study including 1,594 cases of HNC and 1,292 hospital controls. The association of HNC with tobacco and alcohol was estimated by the odds ratio and respective 95% confidence intervals through non-conditional logistic regression, adjusted for age, sex, schooling, consumption of fruits and vegetables, alcohol drinking (to examine the tobacco effect), and tobacco smoking (to examine the alcohol effect). The proportions of HNC attributable to tobacco and alcohol were estimated through the attributable fraction (AF) calculation. Separate estimates were made for Goiânia (Midwest), Rio de Janeiro and São Paulo (Southeast) and Pelotas and Porto Alegre (South). Results: The HNC fraction attributable to smoking was slightly higher in Goiânia (AF = 90%) than in cities in the Southeast (AF = 87%) and South (AF = 86%). The HNC fraction attributable to the consumption of alcoholic beverages presented similar and higher results in the cities of Southeast (AF = 78%) and South (AF = 77%) than in Goiânia (AF = 62%). Conclusion: The HNC fractions attributable to smoking were more expressive than for alcohol consumption. Although with discrete distinctions between them, the AFs to tobacco smoking and alcohol consumption in HNC observed in the cities of these three Brazilian regions were similar to those obtained in Latin America studies, but they were higher than in other parts in the world.