Cancer Immunotherapy, A Simple Guide To Different Types, And Its Uses In Cancer Treatment
Immunotherapy has now emerged as the fourth pillar of cancer treatment standing together with surgery, radiotherapy and chemotherapy.
Immunotherapy is treatment that makes use of a person’s immune system to fight diseases such as cancer.
This can be done in a couple of ways:
1. Stimulating the own immune system to work harder or smarter to attack cancer cells
2. Giving the patient immune system components, such as man-made immune system proteins
Some types of immunotherapy are also called:
1. Biologic therapy - treatment using the biological use of living organisms e.g. cancer vaccine
2. Targeted therapy - targeted at the specific cancer cells
Other new Cancer therapies are:
Adoptive T-cell Transfer Therapy
The purposes of cancer immunotherapy are to kill or control cancer cells by activating, or reactivating the immune system.
1.Controlling the immune system: immune checkpoints
The activity of the immune system is changed and carefully controlled by costimulatory molecules called immune checkpoints.
Immune checkpoints of relevance to cancer are CTLA4, PD1 and PDL1.
If the signals are largely positive, the immune cell is triggered and is ready to attack the antigen presented by the target cell.
2.Cancer immunosurveillance and immunoevasion
The moment tiny cancers form, the abnormal proteins they express from mutated genes produce so-called neoantigens that can be identified by the immune system by antigen presentation, targeting the mutated cell for destruction.
Cancers are corrected by this process, and may be eradicated at this point; known as immunosurveillance.
Cancer immunotherapies attempt to rectify these escape mechanisms at many points, but a key mechanism for cancer cells to evade the immune system seems to be by negative immune checkpoint signaling
Doctors have find ways to help the immune system identify cancer cells and strengthen its response so that it will destroy them.
The main forms of immunotherapy now being used to treat cancer are:
1. Monoclonal antibodies:
Monoclonal antibodies work by binding to cancer cells, allowing the immune system to find, attack, and kill the cells
Other monoclonal antibodies work by obstructing signals on the surface of the cancer cell that tell it to divide.
Another type of monoclonal antibody carries radiation or a chemotherapy drug to cancer cells.
Chronic lymphocytic leukemia
Anaplastic large cell lymphoma
Advanced colon or rectal cancer
Cancers of the head and neck
2. Immune checkpoint inhibitors:
Immune checkpoint inhibitors are a newer form of monoclonal antibody that works on these checkpoints to boost the immune system so it can attack cancer cells.
Melanoma of the skin
Non-small cell lung cancer
3. Cancer vaccines:
Vaccines are materials put into the body to induce an immune response against certain diseases.
But some vaccines such as HPV can assist in preventing or treating cancer.
3. Other, non-specific immunotherapies:
These treatments improve the immune system in a general way, but this can still assist the immune system attack cancer cells.
Interleukin-2 (IL-2) helps immune cells grow and divide more quickly
Interferon alpha (INF-alfa) induces certain immune cells more capable to attack cancer cells
Immunotherapy is less toxic than chemotherapy and radiation because the body cells are used to fight cancer and not toxins.
It is therefore safer.
TABLE OF CONTENT
Chapter 1 Immunotherapy
Chapter 2 Immune System and Cancer
Chapter 3 Types of Immunotherapy
Chapter 4 Destruction of Cancer Cells by Immunotherapy
Chapter 5 Recent Cancer Immune Treatment
Chapter 6 Immunotherapy Against Melanoma
Chapter 7 Immunotherapy Against Lung Cancer
Chapter 8 Immunotherapy Against Other Cancers