The study of the relationship and interactions between the immune system and cancer or malignant cells is known as cancer immunology.
A malignancy refers to cancerous cells that have the potential to invade and destroy tissue. The growth of malignant cells is often fast and uncontrolled due to the changes in their genetic makeup. [2]
The body monitors, detects and destroys malignant cells through a process called immunosurveillance. Immunosurveillance can be used by the immune system to detect any early warning signs of possible damaged cells such as cancer, before they are able to develop further. [3] It is also able to inhibit carcinogenesis and help maintain normal cellular homeostasis. However it is believed that immunosurveillance is only a more general process of cancer immunoediting. [4]
Immunoediting is a process where the body is protected from cancer cell growth and the development of tumour immunogenicity by the immune system. It consists of three main phases, elimination, equilibrium and escape, also known as the three E's. [5]
* Elimination phase:
* Equilibrium Phase:
Tumor cells that have survived enter the equilibrium phase. Lymphocytes and IFN-gamma exert a certain amount of pressure on to the tumor cells which are genitically unstable and rapidly mutating. [6]
* Escape phase:
Tumor cells then enter the escape phase due to the fact that they have built up resistance to elimination. Tumor cells grow and expanded uncontrollably which can result in malignancies. [6] This occurs due to the balance between the immune system and the tumor to be disturbed resulting in the tumor taking over. There is rapid tumor growth due to immune exhaustion or inhibition due to the tumor being resistant to the immune systems efforts to kill it.[7]
A Diagram to illustrate immunoediting:
To conclude, I do believe that there is a link between the immune system and the development of a malignancy. Tumor infiltration by lymphocytes is seen as a reflection of a tumor-related immune response[6].
