||Gaudet MM, Kitahara CM, Newton CC, Bernstein L, Reynolds P, Weiderpass E, Kreimer AR, Yang G, Adami HO, Alavanja MC, Beane Freeman LE, Boeing H, Buring J, Chaturvedi A, Chen Y, D'Aloisio AA, Freedman M, Gao YT, Gaziano JM, Giles GG, Håkansson N, Huang WY, Lee IM, Linet MS, MacInnis RJ, Park Y, Prizment A, Purdue MP, Riboli E, Robien K, Sandler DP, Schairer C, Sesso HD, Ou Shu X, White E, Wolk A, Xiang YB, Zelenuich-Jacquotte A, Zheng W, Patel AV, Hartge P, Berrington de González A, Gapstur SM
||BACKGROUND: Associations between anthropometry and head and neck cancer (HNC) risk are inconsistent. We aimed to evaluate these associations while minimizing biases found in previous studies. METHODS: We pooled data from 1,941,300 participants, including 3760 cases, in 20 cohort studies and used multivariable-adjusted Cox proportional hazard regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of anthropometric measures with HNC risk overall and stratified by smoking status. RESULTS: Greater waist circumference (per 5 cm: HR = 1.04, 95% CI 1.03-1.05, P-value for trend = <0.0001) and waist-to-hip ratio (per 0.1 unit: HR = 1.07, 95% CI 1.05-1.09, P-value for trend = <0.0001), adjusted for body mass index (BMI), were associated with higher risk and did not vary by smoking status (P-value for heterogeneity = 0.85 and 0.44, respectively). Associations with BMI (P-value for interaction = <0.0001) varied by smoking status. Larger BMI was associated with higher HNC risk in never smokers (per 5 kg/m(2): HR = 1.15, 95% CI 1.06-1.24, P-value for trend = 0.0006), but not in former smokers (per 5 kg/m(2): HR = 0.99, 95% CI 0.93-1.06, P-value for trend = 0.79) or current smokers (per 5 kg/m(2): HR = 0.76, 95% CI 0.71-0.82, P-value for trend = <0.0001). Larger hip circumference was not associated with a higher HNC risk. Greater height (per 5 cm) was associated with higher risk of HNC in never and former smokers, but not in current smokers. CONCLUSIONS: Waist circumference and waist-to-hip ratio were associated positively with HNC risk regardless of smoking status, whereas a positive association with BMI was only found in never smokers.