The immune system is able to act against cancer cells and consequently these cells have developed a range of responses to evade or suppress the immune systems anticancer responses. The concept of cancer immunotherapy is based on techniques developed to restore or boost the ability of the immune system to recognize and target tumor cells. It is known that colon cancer does initiate an immune response and that this type of cancer initiates pathways and responses to evade or suppress the immune system. This chapter will discuss some of the dominant therapies being developed to treat colon cancer based on the concept of cancer immunotherapy. Cancer vaccines are based on the concept of providing the immune system with antigen targets derived from tumor-specific molecules, while monoclonal antibodies involve the development of antibodies specifically targeting proteins expressed on the surface of tumor cells. Antibody-based immunotherapy has further applications in the use of bispecific antibodies (BsAb), which are synthetic antibodies designed to be able to recognize two different antigens or epitopes and in this way can increase the immunoresponse and limit immune evasion observed in mono-targeted therapy. Immune checkpoint inhibitors target proteins that are responsible for keeping immune responses in check. Tumor cells overexpress these proteins in order to evade the immune response. Blocking these proteins will lead to an increased immune response against these cells. Cytokine-based immunotherapies involve the use of the immune systems’ own molecular messengers that are responsible for a robust immune response, to boost the antitumor response of the immune system. Oncolytic viral therapy is based on the use of viruses that selectively infect and replicate in cancer and associated endothelial cells and subsequently kills these cells. Adoptive immunotherapy involves the use of immune cells from the patient to be cultured and altered in the laboratory and then reintroduced to boost the immune response. This is normally performed with T cells. Immunotherapy may be the next logical step in the development of an effective therapy for colon cancer and other cancers. The combination of these therapies with traditional chemotherapy or radiotherapy has shown promise in cancer treatment.
Part of the book: Colorectal Cancer