Purpose: Little is known about the causes of central nervous system tumors in children. An inverse association between asthma and brain cancer was found in adults, but there is a dearth of studies in children. The goal of this study was to evaluate the association between asthma and brain cancer in children.
Methods: Two hundred and seventy-two cases of children with brain tumor diagnosed between 0 and 14 years of age in the Province of Québec, Canada, between 1980 and 1999 and 272 incidence density-matched controls were included in the study. The parents of cases and controls were interviewed by phone using structured questionnaires. Besides asthma in children, family history of asthma, the presence of other atopies, and medication intake were also investigated. Conditional logistic regression was used to analyze the data.
Results: Brain tumor risk was decreased in children with asthma (OR, 0.55; CI 95%, 0.33-0.93), with eczema (OR, 0.52; CI 95%, 0.17-1.57), and with both asthma and eczema (OR, 0.76; CI 95%, 0.18-3.2). Maternal or sibling asthma did not modify the effect of asthma on central nervous system (CNS) tumors, while father's asthma seemed to increase the risk, but numbers were small. Antiasthma medications such as inhaled corticosteroid and beta agonists seemed to increase the risk of CNS tumors (OR for steroids, 2.55; CI 95%, 0.79-8.20 and OR for inhaled beta agonist, 1.62; CI 95%, 0.57-4.63).
Conclusions: This study strengthens the hypothesis of inverse association between asthma and brain cancer in children, but family history and medications for asthma need further investigation.