Immune system is a body defense system comprises of a network of special cells, tissue, organs, that safeguard a person from infections or other diseases. The immune system keeps record of all of the substances normally found in the body. So, any foreign substance such as germs or cancer cells when make entry into the system the immune system doesn't recognize and activates the network of cells like B cells or T Cells or macrophages there-by causing the immune system to kill it or discard it from the system.
Therapy involve in the treatment of diseases that uses components of an immune system to fight against different diseases is referred as immunotherapy and the immunotherapy subjected for treatment of disease especially cancer is called as cancer immunotherapy. Cancer immunotherapy propagated in two distinct ways for treatment of cancer. Either stimulates the immune system to attack cancer cells or provides artificial components of immune system that play important role to bypass certain denova pathway's to fight against cancer. Sometimes, the immune system may not be able to recognize and identify targeting cancer cells as foreign. This is because, cancer starts with genetic alteration in the cells and thus prorogate to grow out of control vary rapidly.
Types of cancer immunotherapy
The main types of immunotherapy used to treat cancer are:
Monoclonal antibodies: These are artificial form of immune system proteins, referred as monoclonal antibodies. One of the process through which the immune system attacks foreign substances in the body is by synthesizing large numbers of antibodies. An antibody is a protein that recognizes specific antigen. Once antigen is recognize, immune system activates the cascade there by destroy the cells containing the antigen. Scientist has reported that antibodies can be design that specifically targets a certain antigen, which is found on cancer cells. There by multiple copies can be produced and are known as monoclonal antibodies (mAbs).Monoclonal antibodies are used to treat several diseases, it include some types of cancer. Monoclonal antibody can be synthesized by first identifying the specific antigen to attack. For cancer, this is not an easier task, and thus mAbs have proven to be more effective against some cancers than others. With the new update, the US Food and Drug Administration (FDA) have approved more than a dozen mAbs to treat cancers. Scientists have recognized and reported more antigens linked to cancer, thus are been able to make mAbs against more and more types of cancer. mAbs are of different types like naked mAbs. Naked mAbs work by getting attach to antigen on cancer cell or by binding to antigen on neighboring non cancerous cell. mAbs doesn't bind to any drug or radioactive materials. However, the form of monoclonal antibodies that is used either by binding with drug or with radioactive materials is known as conjugated monoclonal antibodies.
Immune checkpoint inhibitors: These are the basically drugs which recognizes specific type of molecules of the immune system for egg PD-1 that are found on T cell which has to be activated or inactivated to propagate immune response.
Cancer vaccines: Vaccines that target the viruses that can cause certain cancer are referred as cancer vaccines. For example some strains of human papilloma virus (HPV) are responsible for cervical, anal, throat, and some other form of cancers. Thus, vaccines used against HPV may protect against these cancers.
Other, non-specific immunotherapies: It involves the role of cytokines that include interleukin and interferons in controlling the growth and activity of other immune system. Interleukin act as chemical signal between lymphocytes. An artificial version of IL-2 is reported to treat advanced kidney cancer and metastatic melanoma. Other interleukins, such as IL-7, IL-12, and IL-21, are being used as adjuvant or mediator to enhance immune response against cancer. Interferon's advances the potential of immune system against cancer cells. IFN-Alfa is used to treat variety of cancer like Hairy cell leukemia, Chronic myelogenous leukemia (CML), Follicular non-Hodgkin lymphoma, Cutaneous (skin) T-cell lymphoma, Kidney cancer, Melanoma, Kaposi sarcoma.
Immunotherapy fight against cancer
Some monoclonal antibodies bind to specific proteins on cancer cells thus flags the cells so that immune system can identify and kill those cells. Whereas, according to literature, some may work by releasing the certain inhibitors on the immune system so that it can kill cancer cells. For egg PD-1/PD-L1 and CTLA-4 pathways are potent pathway to the immune system's ability to control cancer growth and referred as "immune checkpoints." Many cancers use these pathways to overcome the immune system. The immune system act against cancer by blocking these pathways with specific antibodies called immune checkpoint inhibitors. Once the immune system is able to recognize and respond to the cancer, it can inhibit or slow down cancer cell growth.
Oncolytic virus therapy functions by genetically modifying viruses to kill cancer cells. A virus injected into the tumor where it starts replicating and makes number of copies of itself. As a result, the cells burst and die. Once cell get burst they release specific substances called antigens which get recognize by the immune system and trigger all the cancer cells. Thus, immune system targets all the cancer cells in the body that have those antigens and kill them. Recent research has reported new molecules that help to differentiate cancer cells from normal cells with the help of mAbs. Thus, new form of mAbs are synthesize that can bind to drug or other molecules and can produce effect which is more strong and powerful. These newly synthesize mAbs are less likely to cause immune reactions with more pronounced effect. Furthermore, drug like thalidomide, lenalidomide and pomalidomide are some known immunomodulating drugs (or IMiDs) that are prescribed by medical practioners. The general concept about working mechanism of these drugs is to boost the immune system. These drugs are prescribed against the usage to treat multiple myeloma. Bacilli Calmette-Guérin (BCG) is one of the most popular immunotherapy used for treatment of cancer. It is basically a germ that activates the immune system. It doesn't cause serious illness in humans. BCG was thus one of the traditional immunotherapy used against treatment of cancer. However, cancer immunotherapy is not very effective in all cancer treatment.
Importance of Cancer immunotherapy
The need for quality in cancer education is in good demand. Cancer has become the most common cause of death around the globe. Thus, new methods and mechanism are introduced for treatment of cancer. Introducing cancer immunotherapy in academic curriculum will advance consistency of standards across all universities, ensures appropriate exposure of medical students to tertiary cancer treatment across the globe. Competing priorities for cancer immunotherapy across the medical curriculum remain a challenge. Ideal oncology curriculum including cancer immunotherapy can help medical students to provide a common standard of cancer education. It has to be included as it not only gives an invaluable insight into the patients' perspective on cancer and its treatments, but also as it ensure the present most acceptable method for treatment of cancer that encompass combination modality therapies against cancer control. Cancer learning remains incomplete until and unless concept and maintains relevance to cancer immunotherapy is understood clearly. It has to be reviewed and updated to incorporate changes in knowledge and practice in cancer control.