Insights from IgE Immune Surveillance in Allergy and Cancer for Anti-Tumour IgE Treatments

SIMPLE SUMMARY: The growing field of AllergoOncology has illustrated potential for the use of IgE in cancer immunotherapy; however, there is still much to be explored within this field, particularly surrounding the links between IgE, allergy, and cancer. Exploring such links may provide useful insights to guide novel IgE-based strategies targeting cancer. Here, we summarise the existing data on both IgE in cancer epidemiology and tumour immunosurveillance, leading to the proposal of a new hypothesis, the combinatorial hypothesis, which attempts to encapsulate the complexity of the relationship between IgE-associated immune responses with cancer; and we discuss how these insights may shape the next generation of IgE-based therapeutics. ABSTRACT: IgE, the predominant antibody class of the allergic response, is known for its roles in protecting against parasites; however, a growing body of evidence indicates a significant role for IgE and its associated effector cells in tumour immunosurveillance, highlighted by the field of AllergoOncology and the successes of the first-in-class IgE cancer therapeutic MOv18. Supporting this concept, substantial epidemiological data ascribe potential roles for IgE, allergy, and atopy in protecting against specific tumour types, with a corresponding increased cancer risk associated with IgE immunodeficiency. Here, we consider how epidemiological data in combination with functional data reveals a complex interplay of IgE and allergy with cancer, which cannot be explained solely by one of the existing conventional hypotheses. We furthermore discuss how, in turn, such data may be used to inform future therapeutic approaches, including the clinical management of different patient groups. With epidemiological findings highlighting several high-risk cancer types protected against by high IgE levels, it is possible that use of IgE-based therapeutics for a range of malignant indications may offer efficacy to complement that of established IgG-class antibodies.