Body mass index and risk of head and neck cancer by race: the Carolina Head and Neck Cancer Epidemiology Study

Purpose: Most studies, primarily conducted in populations of European ancestry, reported increased risk of head and neck cancer (HNC) associated with leanness (body mass index [BMI] <18.5 kg/m(2)) and decreased for overweight or obesity (25.0 to <30.0 and >30 kg/m(2), respectively), compared with normal weight (18.5 to <25.0 kg/m(2)). Methods: The Carolina Head and Neck Cancer Epidemiology Study is a population-based, racially diverse case-control study of 1289 incident HNC cases (330 African Americans) and 1361 controls (261 African Americans). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for associations between BMI 1 year prediagnosis and HNC risk stratified by race and adjusted for age, sex, smoking, alcohol, and education. Results: Multiplicative interaction between BMI and race was evident (P-int = .00007). Compared with normal weight, ORs for leanness were increased for African Americans (OR, 3.91; 95% CI, 0.72-21.17) and whites (OR, 1.48; 95% CI, 0.60-3.65). For overweight and obesity, ORs were decreased in African Americans (OR, 0.51; 95% CI, 0.32-0.83 and OR, 0.47; 95% CI, 0.28-0.79, respectively) but in not whites. The increased risk associated with leanness was greater for smokers than nonsmokers (P-int = .02). Conclusions: These data, which require replication, suggest that leanness is associated with increased HNC risk among African Americans to a greater extent than whites and overweight and obesity is associated with decreased HNC risk only among African Americans. (C) 2014 Elsevier Inc. All rights reserved.