Allergies and risk of head and neck cancer.
BACKGROUND
Individuals with allergies have a heightened Th2 (T helper 2) immunity, which may provide advantages in controlling tumor growth. Inverse associations have been reported among individuals with allergies and risk of brain and pancreatic cancers.


METHODS
We examined the relationship between allergies and risk of head and neck squamous cell carcinoma (HNSCC) in a population-based case-control study with 1,014 cases and 1,193 frequency-matched controls. Logistic regression models were used to estimate odds ratios (OR) and 95 % confidence intervals (95 % CI) controlling for age, sex, race, smoking history, alcohol consumption, and education. In addition, in a subset of the population, models were adjusted for HPV16 status.


RESULTS
Individuals with allergies had a 19 % lower risk of HNSCC (OR = 0.81, 95 % CI = 0.67-0.98). Associations with allergies were stronger for laryngeal (OR = 0.66, 95 % CI = 0.45-0.97) and oropharyngeal (OR = 0.73, 95 % CI = 0.57-0.92) cancers, while no association was observed for oral cavity cancers (OR = 0.98, 95 % CI = 0.76-1.26). History of asthma was not associated with overall HNSCC, but the association was statistically significant for oropharyngeal cancer (OR = 0.67, 95 % CI = 0.44-0.99). HPV16 status did not confound or modify the associations with allergies.


CONCLUSIONS
Elevated Th2 immunity in individuals with history of allergies and asthma may reduce the risk of HNSCC. Additional research into related mechanisms may provide new insights into how to treat HNSCC.


CONCLUSIONS
These findings may provide new insight into biological pathways that could lead to a better understanding of the etiology of this disease.
Department of Epidemiology, Division of Biology and Medicine, Brown University, Providence, RI, USA. dominique_michaud@brown.edu
Dominique S
DS
Michaud
Scott M
SM
Langevin
Melissa
M
Eliot
Heather H
HH
Nelson
Michael D
MD
McClean
Brock C
BC
Christensen
Carmen J
CJ
Marsit
Karl T
KT
Kelsey
D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D016022:Case-Control Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D052162:Human papillomavirus 16 / Q000302:isolation & purification; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D030361:Papillomavirus Infections / Q000453:epidemiology / Q000276:immunology; D012307:Risk Factors; D000077195:Squamous Cell Carcinoma of Head and Neck