ABSTRACT: Smoking and alcohol exposure continue to be the dominant risk factors for the development of head and neck squamous cell carcinoma (SCCHN) worldwide. Moreover, human papillomavirus (HPV) is associated with SCCHN, particularly SCC of the oropharynx (SCCOP). Body mass index (BMI) has been reported as a possible risk factor for SCCHN, yet the data available so far about the relationship between BMI and SCCHN risk have been mixed. We sought to clarify this relationship. BMI and demographic, clinical, and epidemiological information at diagnosis were collected from 2310 SCCHN cases and 1915 controls (who were cancer-free) from October 2001 through May 2013. The odds ratios (ORs) and 95 percent confidence intervals (95% CI) were determined using the logistic regression process. Multivariable models were used to evaluate the strength of the relation between BMI and SCCHN risk. At diagnosis, 64 (2.8%) of the cases were underweight (BMI <18.5 kg/m2), 661 (28.6%) were normal weight (BMI 18.5<25 kg/m2), 833 (36.1%) were overweight (BMI 25<30 kg/m2), and 752 (32.6%) were obese (BMI ≥30 kg/m2). Comparatively, the ORs (95% CIs) for SCCHN associated with being underweight, overweight, and obese were 2.6 (1.54.7), 0.7 (0.6-0.8), and 0.8 (0.7-0.9), respectively, after adjusting for age, gender, race/ethnicity, smoking, and alcohol consumption. On analysis stratified by tumor sites, the risk of SCCOP among patients seropositive for HPVE6 and/or HPVE7 was higher among the overweight (OR, 5.4, 95% CI, 1.3-23.1) and obese patients (OR, 2.4, 95% CI, 1.1-7.6) compared to the normal weight patients. These findings suggest that pretreatment BMI could be a major risk factor for SCCHN, and the association between BMI and HPV may increase the risk of SCCOP.
