ABSTRACT
OBJECTIVE: Review the literature on the relationship between cancer and allergy. METHOD: Study articles indexed in the databases of PubMed, Lilacs, Bireme and Scielo to verify whether there is a relationship among cancer, allergy, allergy skin tests and serum levels of immune markers. RESULTS: Several studies have suggested an inverse association between allergy and cancer, while others have found no relationship between these entities, while still other authors have shown an increased risk of some cancers in allergic patients. The conflicting findings in previous studies are due in part to the method used, such as different definitions and measures for atopy, as well as variations in the control of confounding factors such as smoking and obesity. It is noteworthy that most of the studies were conducted in several countries and with different parameters. CONCLUSION: There is a lower incidence of allergy in patients with cancer, especially colorectal, pancreatic, and glioma.