Worldwide wide a high prevalence of morbidity and mortality related to allergies and cancer is noticeable. Treatment-related expense increases with these diseases’ incidence. The relation between allergies and cancer is contradictory. Allergies occur because of inflammatory reactions that may have a link with carcinogenesis, though this finding has been limited within specific areas. In another course of finding stated that immunosurveillance is increased allergic reaction give systemic effects that provide the cancer-preventive effect.
Hypersensitivity reactions because of specific type Th2 immunological mechanisms that are mediated through different inflammatory mediators that release from specific cells of the immune system lead to allergies.
In 1913, allergies, or anaphylaxis was first discovered by Charles Richet and Paul Portier as a result of immunizing with actinia extracts several times. Later, at the early phase of the 21st century, the European Academy of Allergy and Clinical Immunology (EAACI) and the World Allergy Organization (WAO) specifically clarify the concept of anaphylaxis based on clinical independent mechanisms.
In the current scenario, the global prevalence of anaphylaxis is increasing because of pollen outbreaks, the increasing incidence of atopic diseases, and food allergies. Asthma is one of the severe allergic reaction occurs due to chronic airway inflammatory condition, though the severity of inflammation varies from person to person. Millions of people across the globe have asthma.
For several decades epidemiological, oncological, and immunological researchers have had a constant interest to find out the biological relationship between cancer and allergies. Several research reports reflect a complex relationship between these chronic conditions. However, the precise association between these two conditions still requires examining because of different results obtained from research reports.
The T-cell response differs from Th1 type to a principal activity of Th2 due to hypersensitivity reactions in the immune system. Many chronic diseases like diabetes and cancer are resultant of the coexistence of Th2 disorders that mediated through Th1.
However, the controversial and contradictory results obtained from epidemiology studies indicate two trends. The first trend of explanation is based on the immunosurveillance hypothesis that stated that the enhanced immune surveillance in the post immune hyper-responsiveness could inhibit or exert a protective effect against cancer development. Likewise, the prophylaxis hypothesis indicates that the allergy symptoms exert physical effects that potentially remove carcinogens and prevent cancer. Compared with the general population, individuals with any type of allergy have a decreased risk of colorectal cancer, non-Hodgkin lymphoma, esophageal cancer, pancreatic cancer, stomach cancer, larynx cancer, glioma, and uterine body cancer.
In contrast, the opposite hypothetical theory stated that immune response deviation toward Th2 favors the cancer development or chronic inflammation associated with allergy favors mutation. Therefore, the risk of cancer development increases with allergy. Researchers had been reported that increased risks for bladder cancer, lymphoma, myeloma, and prostate cancer exist among those with allergies.
From these contrasting statements, we can conclude that the association between allergies and cancer is site-specific.