Final answer:
Cancer is not a type of hypersensitivity reaction but is instead related to the immune system's failure to control abnormal cell growth. Hypersensitivities involve maladaptive immune responses that can be immediate or delayed, mediated by B cells or T cells respectively, and cancer is associated with immunodeficiency rather than hypersensitivity.
Step-by-step explanation:
Cancer is not an example of a hypersensitivity reaction. The four types of hypersensitivity reactions are immune responses that can sometimes become maladaptive. Type I hypersensitivity is an immediate reaction and is the typical allergic response mediated by B cells and IgE antibodies, such as hay fever or anaphylaxis.
Type II hypersensitivity involves antibodies that react to antigens on the surface of cells, causing a cytotoxic response; an example of this would be a hemolytic transfusion reaction. Type III hypersensitivity involves immune complex-mediated reactions. Type IV hypersensitivity, or delayed hypersensitivity, is regulated by T cells rather than antibodies and involves a cellular immune response that takes 24-72 hours to develop, as seen with reactions to poison ivy or the tuberculin skin test.
Immunodeficiency refers to the under-reactive responses of the immune system, which can either be inherited or acquired, and which leaves an individual more susceptible to infections and diseases, such as cancer. However, cancer itself results from uncontrolled cell growth and is related to the immune system's inability to adequately control or eradicate cancer cells, but is not a hypersensitivity reaction.