Source: http://cancerres.aacrjournals.orgAuthors: Paolo Boffetta, Mia Hasibe & On Behalf Of INHANCE Consortium  Abstract: Cigarette smoking and alcohol drinking account for at least 75% of head and neck cancers. A precise understanding of the independent effect of each of these factors in the absence of the other has important implications, in terms of elucidating the mechanisms of head and neck carcinogenesis and assessing the effect of interventions aimed to control either risk factor.We determined the extent to which head and neck cancer is associated with cigarette smoking among never-drinkers and alcohol drinking among never-tobacco users. We pooled individual-level data across 15 individual case-control studies including 10,244 head and neck cancer cases and 15,227 controls.There were 1,072 cases and 5,775 controls who never used tobacco, and 1,598 cases and 4,051 controls who never drank alcohol. Cigarette smoking increased the risk of head and neck cancers [odds ratio (OR)=2.10, 95% confidence interval (CI) 1.49-2.95] among never-drinkers, with clear dose-response relationships for frequency, duration and packyears of cigarette smoking. Approximately 24% of head and neck cancer cases among non-drinkers would have been prevented if these individuals had not smoked cigarettes. Among never-tobacco users, an increasing risk of head and neck cancer was detected for increasing alcohol drinking frequency (p for trend<0.001), but the effect was apparent only at high doses.Our results represent the most precise estimate available of the independent effect of each of the two main risk factors of head and neck cancer and exemplify the strengths of large-scale consortia in cancer epidemiology.  *This news [...]