Antihistamine use and immunoglobulin E levels in glioma risk and prognosis.

OBJECTIVE: An inverse association between personal history of allergies/asthma and glioma risk has been fairly consistently reported in the epidemiologic literature. However, the role of regular antihistamine use remains controversial due to a small number of studies reporting contradictory findings. We evaluated the association between regular use of oral antihistamines and glioma risk, adjusting for a number of relevant factors (e.g., immunoglobulin E levels and history of chickenpox).
METHODS: We used a subset of the Harris County Case-Control Study, which included 362 pathologically confirmed glioma cases and 462 cancer-free controls, to evaluate this association using unconditional multivariable logistic regression. These models were run among the overall study population and stratified by allergy status. Cox regression was utilized to examine whether antihistamine use was associated with mortality among all cases and separately among high-grade cases.
RESULTS: Antihistamine use was strongly associated with glioma risk among those with a positive allergy/asthma history (OR: 4.19, 95% CI: 2.06-8.51), but not among those with a negative history (OR: 1.59, 95% CI: 0.95-2.67). There were no significant associations between antihistamine use and survival among cases.
CONCLUSION: The current study implies that regular antihistamine use may increase glioma risk. However, several larger studies are necessary before definitive conclusions can be drawn.