Body mass index and the risk of head and neck cancer in the Chinese population.

To investigate potential associations between body mass index (BMI) and head and neck cancer (HNC) risk in an East Asian population.We conducted a hospital-based multicenter case-control study in East Asia including 921 cases and 806 controls. We estimated the odds ratios (ORs) and 95% confidence intervals (95% CI) for HNC risks by using logistic regression, adjusting on potential confounders.

Compared to normal BMI at interview (18.5-<25 kg/m²), being underweight (BMI < 18.5 kg/m²) was associated with a higher HNC risk (OR = 2.71, 95% CI 1.40-5.26). Additionally, obesity (BMI > 30 kg/m²) was associated with a lower HNC risk (OR = 0.30, 95% CI 0.16-0.57). Being underweight at age 20 was also associated with an increased risk of HNC. However, being underweight at 5 years or 2 years before interview was not associated with a higher risk of HNC.

We observed an inverse association between BMI and HNC risk, which is consistent with previous studies in other geographic regions. Being underweight at age 20 was also associated with a higher risk of HNC, suggesting that reverse causality was not the main source of the association.