Introduction: Atopic syndrome (allergic rhinitis, asthma and eczema) and food allergies are frequently reported, especially in developed countries. Studies have previously suggested an inverse association between allergic diseases and cancer. The aim of this study was to investigate the association between allergic diseases and different types of cancers by performing a systematic review of the literature.
Methods: A systematic literature search of Ovid Medline, Embase, Web of Science, Cochrane Library and Google Scholar was performed for studies on the association between allergic diseases and cancers.
Results: We identified a total of 5868 articles through our search, with 145 articles describing an association between allergic diseases and cancers. Allergies were associated with reduced risk of brain cancer, pancreatic cancer and melanoma and with possibly reduced risk of lymphatic and hematopoietic cancer, colorectal cancer, urogenital cancers of women and cancers in general. Asthma, but not atopy without asthma, was however associated with increased risk of lung cancer. There is possibly no association between allergic diseases and the risk of breast cancer and prostate cancer.
Conclusion: Overall, allergic diseases are inversely associated with the risk of cancers.