Patients with a history of asthma and hay fever face a lower overall risk of cancer mortality than those with neither of these allergic conditions, according to a report in the August American Journal of Epidemiology.
Previous studies have suggested an inverse association between allergy and cancer development, the authors explain, but some reports have shown an increased risk of lung cancer in asthma patients.Dr. Michelle C. Turner from University of Ottawa, Ontario, Canada and associates used data from the American Cancer Society Cancer Prevention Study II to examine the association between allergy and cancer risk.Participants with histories of both asthma and hay fever were 12% less likely to die from cancer, the authors report. Those with hay fever only were 8% less likely and those with asthma and/or hay fever were 6% less likely than patients with neither asthma nor hay fever to die from cancer.A history of asthma only was associated with a lower risk of leukemia mortality but a higher risk of lung cancer mortality, the report indicates. A history of hay fever only was associated with a significantly lower risk of pancreatic cancer mortality.The inverse associations between overall cancer mortality and lung cancer mortality among individuals with hay fever only and asthma and/or hay fever disappeared when only never smokers were included in the analysis, the investigators report.”Collectively, these results suggest an association between a history of allergy and cancer mortality,” the authors conclude. “However, the strength of the evidence for this association is limited.””Additional large prospective studies with better allergy indicators and cancer incidence, as well as laboratory studies examining potential biological mechanisms for a potential association, would be useful,” Dr. Turner told Reuters Health.(Source: Am J Epidemiol 2005;162:212-221: Reuters Health: Oncolink: Will Boggs, MD: July 2005.)