Minireview : immunotherapy and its role in cancer

Abstract

Immunotherapy entails treatments that stimulate, enhance or inhibit a patient’s own im-mune system to challenge a specific disease. The immune system is capable of distinguishing between healthy and tumorigenic cells and the following treatments are aimed at those cells that become cancerous. There are three approaches employed in immunotherapy namely monoclonal antibody administration, immunotherapy making use of cytokines and vaccine-based immunotherapy. Artificially produced monoclonal antibodies are employed to target tumorigenic cells by exerting an antagonistic effect on growth factor receptors or to contrib-ute to the induction of antibody-dependent cell-mediated cytotoxicity. These actions result in the disruption of tumorigenic cells or improvement of the immune response directed against tumorigenic cells. Monoclonal antibodies blocking cytotoxic T-lymphocyte associated pro-tein 4 resulted in tumor regression. Several cytokines are responsible for the stimulation of immune responses directed against tumorigenic cells. Various cytokines also stimulate tumor necrosis factor family members for induction of apoptosis in tumorigenic cells. Vaccines en-tail an active immunotherapeutic approach in which an immune response is induced by the external administration of antigens. Three different cancer vaccines are currently in use namely vaccines preventing cancer recurrence of treated cancers, eradication of cancer cells not destroyed by previous treatment and targeting of cancer-causing viruses. However, it is clear that immunotherapy should be used in combination with other known treatments to have the optimal effect.