Alcohol consumption, cigarette smoking and the risk of subtypes of head-neck cancer: results from the Netherlands Cohort Study

Background: Prospective data on alcohol consumption, cigarette smoking and risk of head-neck cancer (HNC) subtypes, i.e. oral cavity cancer (OCC), oro-/hypopharyngeal cancer (OHPC), and laryngeal cancer (LC), are limited. We investigated these associations within the second largest prospective study on this topic so far, the Netherlands Cohort Study. Methods: 120,852 participants completed a questionnaire on diet and other cancer risk factors in 1986. After 17.3 years of follow-up, 395 HNC (110 OCC, 83 OHPC, and 199 LC) cases and 4288 subcohort members were available for case-cohort analysis using Cox proportional hazards models. Results: For total HNC, the multivariable adjusted incidence rate ratio (RR) was 2.74 (95% confidence interval (CI) 1.85-4.06) for those drinking >= 30 g ethanol/day compared with abstainers; in subtypes, RRs were 6.39 for OCC, 3.52 for OHPC, and 1.54 for LC. Compared with never cigarette smokers, current cigarette smokers had a RR of 4.49 (95% CI 3.11-6.48) for HNC overall, and 2.11 for OCC, 8.53 for OHPC, and 8.07 for LC. A significant, positive, multiplicative interaction between categories of alcohol consumption and cigarette smoking was found for HNC overall (P interaction 0.03). Conclusions: Alcohol consumption and cigarette smoking were independently associated with risk of HNC overall, with a positive, multiplicative interaction. The strength of these associations differed among HNC-subtypes: OCC was most strongly associated with alcohol consumption but most weakly with cigarette smoking, whereas LC was not statistically significantly associated with alcohol consumption

Vitamin and carotenoid intake and risk of head-neck cancer subtypes in the Netherlands Cohort Study

Background: Head and neck cancer (HNC) is the seventh most-common type of cancer worldwide. Evidence regarding the potential protective effect of vitamins and carotenoids on HNC is limited and mostly based on case-control studies. Objective: We evaluated the association of intake of dietary vitamins C and E (including supplementation) and the most-common carotenoids (alpha-carotene, beta-carotene, lutein plus zeaxanthin, lycopene, and beta-cryptoxanthin) and risk of HNC and HNC subtypes in a large prospective study. Design: The Netherlands Cohort Study included 120,852 participants. For efficiency reasons, a case-cohort design was used. At baseline in 1986, participants completed a food-frequency questionnaire. A subcohort was randomly selected from the total cohort. After 20.3 y of follow-up, 3898 subcohort members and 415 HNC cases [131 oral cavity cancer (OCCs), 88 oro-/hypopharyngeal cancer (OHPs), and 193 laryngeal cancer cases] were available for analysis. Rate ratios and 95% CIs for highest (quartile 4) compared with lowest (quartile I) quartiles of vitamin and carotenoid intake were estimated by using the Cox proportional hazards model. Results: A strong inverse association was shown between vitamin C and HNC overall (multivariable-adjusted rate ratio for quartile 4 compared with quartile 1: 0.39; 95% CI: 0.23, 0.66; P-trend <0.001), OCC (multivariable-adjusted rate ratio for quartile 4 compared with quartile 1: 0.35; 95% CI: 0.16, 0.77; P-trend <0.05), and OHPC (multivariable-adjusted rate ratio for quartile 4 compared with quartile 1: 0.29; 95% CI: 0.12, 0.67; P-trend <0.01). No statistically significant results were shown for vitamin E, alpha-carotene, beta-carotene, lycopene, and lutein plus zeaxanthin. The association of vitamin E and HNC was modified by alcohol status (P-interaction = 0.003) with lower risks in alcohol abstainers. Conclusions: With this study, we show an inverse association between intake of vitamin C and the incidence of HNC and HNC-subtypes. Future research is recommended to investigate the underlying mechanisms and to confirm our results, which may be promising for the prevention of HNC