Allergies: Their Role in Cancer Prevention

Abstract

The nature of the biological relationships between cancers and allergies has intrigued researchers and health care providers for five decades. Three hypotheses have been proposed: antigenic stimulation predicts positive associations between cancers and allergies (i.e., allergy sufferers are more likely to get cancer), whereas immunosurveillance and prophylaxis predict inverse associations (i.e., allergy sufferers are less likely to get cancer). Immunosurveillance predicts inverse associations for cancers of all tissues and organ systems, and prophylaxis predicts inverse associations specifically for cancers of tissues and organ systems that interface with the external environment. To comparatively evaluate these hypotheses, we comprehensively reviewed the literature on cancer and allergies. We located 148 papers published from 1955 through 2006 that reported results of 463 studies of relationships between patients' histories of 11 specific allergies and cancers of 19 tissues and organ systems, and 183 studies of patients' histories of multiple allergies in relation to various types/sites of cancers. Analyses of these studies revealed that (1) frequencies of positive, inverse, and null allergy-cancer associations differed considerably among cancers of different tissues and organ systems; (2) more than twice as many studies reported inverse allergy-cancer associations as reported positive associations; (3) inverse associations were particularly common for cancers of the mouth and throat, brain glia, colon and rectum, pancreas, skin, and cervix but (4) particularly rare for cancers of the breast, prostate, and brain meninges, and for myeloma, non-Hodgkin's lymphoma, and myelocytic leukemia; (5) lung cancer was positively associated with asthma but inversely associated with other allergies; (6) inverse associations with allergies were more than twice as common for cancers of nine tissues and organ systems that interface with the external environment compared to cancers of nine tissues and organ systems that do not interface with the external environment; and (7) eczema, hives, and allergies to animal dander and food were most frequently inversely associated with cancers of tissues that interface with the external environment. Taken together, these results are more consistent with the prophylaxis hypothesis than the two alternatives. IgE is a widespread and ancient immunoglobulin isotype in mammals, occurring among all known marsupials, monotremes, and eutherians. The IgE system and its associated allergy symptoms may serve a common protective function: the rapid expulsion of pathogens, dangerous natural toxins, and other carcinogenic antigens before they can trigger malignant neoplasia in exposed tissues.

Primary brain tumours and specific serum immunoglobulin E: a case–control study nested in the European Prospective Investigation into Cancer and Nutrition cohort

“…Whether this is because of a stronger reaction of the immune system of HGG patients on environmental influences (compared with LGG patients) or vice-versa is at this stage only speculative. However, our result supports the observation of Sherman et al (35) who noted that an inverse association with allergies were more often found for cancer of different tissues, including brain tissue, and organ systems that interface with external environment than in those tissue that do not so. The site specificity of the association between allergies and cancer is also described in a review by Merill et al (2007) (36).…”

Epidemiology of Pancreatic Cancer: An Update

“…A possible explanation for this reduction in risk is that the hyperactive immune system of allergic individuals leads to increased surveillance and, thereby, protection against development of pancreatic cancer cells [71] .…”

Immunoglobulin E and cancer: a meta-analysis and a large Swedish cohort study

“…Three distinct perspectives underpin the possible association of atopy with cancer. According to the ''antigenic stimulation'' hypothesis, atopic inflammation contributes to cancer by causing oxidative damage that activates mutations in tumor suppressor genes or post-translational modifications in proteins involved in DNA repair or apoptotic control [5][6][7]. Conversely, the ''immune surveillance'' theory proposes that atopy is a consequence of a generalized enhanced immune responsiveness that has the capability to detect and eradicate dysregulated cells.…”

“…Conversely, the ''immune surveillance'' theory proposes that atopy is a consequence of a generalized enhanced immune responsiveness that has the capability to detect and eradicate dysregulated cells. An inverse association between cancer and allergy is also predicted by the ''prophylaxis'' hypothesis, by which allergic reactions frequently expel mutagenic toxins, microorganisms and environmental contaminants, promote tissue repair, and encourage behavioral avoidance of irritants and toxins antigens [7]. Nonetheless, reports that allergies associate with either reduced or increased risk of cancer are collectively inconsistent [7][8][9].…”

“…Inconsistent findings might also relate to the fact that atopy influences different tissues in different ways. Since allergies occur primarily at body surfaces, it is logical that inverse relations between allergy and cancer may be more overt for cancers of the corresponding tissues and organ systems (e.g., mouth and throat, lungs, skin) versus sites that do not directly interface with the environment (e.g., prostate, breast, hematopoietic tissue) [7]. Indeed, different types of tissue are more generally associated with different immunological reactions [11][12][13], which gives a rationale to study cancers by tissue of origin when investigating the association of cancer and atopy.…”