Men who had a history of asthma or eczema generally had a lower risk of developing cancer, according to a study carried out by researchers at INRS-Institut Armand-Frappier, the Research Centre of the Centre hospitalier de l'Université de Montréal, and McGill University. The findings, published in the Annals of Allergy, Asthma & Immunology, show that male eczema sufferers had a lower risk of lung cancer while those with a history of asthma had a similar effect in relation to stomach cancer.
"Asthma and eczema are allergies brought about by a hyper-reactive immune system - a state which might have enabled abnormal cells to have been eliminated more efficiently, thereby reducing the risk of cancer," explained Professor Marie-Claude Rousseau of the INRS-Institut Armand-Frappier, one of the co-authors of the research.
The researchers analyzed information that was collected in a study on exposures in the workplace and the risk of developing cancer, undertaken between August 1979 and March 1986. It involved 3,300 men, between 35 and 70 years of age, who had been diagnosed with cancer in one of Montreal's 18 hospitals, and a control group of 512 people from the general population who did not have cancer. The researchers used the data from this study to determine if there was a link between allergies such as asthma and eczema and the incidence of eight most common types of cancer.
These findings contribute important knowledge to population health and provide new research leads. Although the study did not allow to identify which specific factors related to asthma and eczema were responsible for reducing the risk of cancer, it offers new angles for research into the molecular and immunological mechanisms that are involved in immunostimulation, a potentially promising strategy for cancer prevention.
The epidemiological study was undertaken by Mariam El-Zein, Marie-Élise Parent, Yves St-Pierre and Marie-Claude Rousseau of the INRS; Khady Kâ of McGill University, and Jack Siemiatycki of the Research Centre of the Centre hospitalier de l'Université de Montréal and of Université de Montréal. It received funding from Health Canada, the Institut de recherche Robert-Sauvé en santé et sécurité au travail du Québec, the Fonds de la recherche en santé du Québec, the Medical Research Council of Canada, the Canadian Cancer Society, and the Canadian Institutes of Health Research.