Prospective studies of body mass index with head and neck cancer incidence and mortality.
BACKGROUND
Results of a pooled analysis of case-control studies show a higher risk of head and neck cancer (HNC) associated with a low body mass index (BMI) and a lower risk associated with being overweight or obese compared with being normal weight. However, these results are prone to bias due to residual confounding by smoking, a strong risk factor, and possible weight loss prior to diagnosis. Using prospectively collected data from the Cancer Prevention Study-II cohort and the Nutrition cohort, we examined the association of BMI with HNC mortality and incidence, overall and by smoking status.


METHODS
Mortality analyses included 1,383 cases among 1,059,153 participants; incidence analyses included 340 cases among 150,262 participants. Multivariable Cox proportional hazard models were used to estimate HRs and 95% confidence intervals (CI) for the association of BMI with HNC incidence and mortality.


RESULTS
Overall, compared with the category of BMI 22.5-24.9 kg/m(2), the categories of BMI 25.0-29.9 kg/m(2) and ≥ 30.0 kg/m(2) were associated with a lower risk of HNC mortality but not incidence. In never smokers, there were no associations of BMI with HNC incidence or mortality. In smokers, BMI < 22.5 kg/m(2) was associated with a higher risk of HNC mortality (HR = 1.42, 95% CI, 1.20-1.67).


CONCLUSIONS
In this prospective cohort, there was no association between BMI and HNC incidence, although BMI was inversely associated with HNC mortality in smokers.


CONCLUSIONS
These suggest that there is no etiologic relationship between BMI and HNC.
Corresponding Author: Mia M. Gaudet, Epidemiology Research Program, American Cancer Society, 250 Williams Street, NW, Atlanta, GA 30303.  mia.gaudet@cancer.org.
Mia M
MM
Gaudet
Alpa V
AV
Patel
Juzhong
J
Sun
Janet S
JS
Hildebrand
Marjorie L
ML
McCullough
Amy Y
AY
Chen
Susan M
SM
Gapstur
D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000209:etiology* / Q000401:mortality*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000401:mortality; D050177:Overweight / Q000150:complications; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate