Immunoediting is a theory within immuno-oncology that describes how normal cells transform into clinically detectable cancer. Immunoediting theorizes that while the immune system protects against cancer, it can also drive the development of tumors that then undergo immunogenic “sculpting.” These tumors can also survive attacks from immune cells.
There are three phases to the immunoediting process, often referred to as the three E’s. These phases include:
- Elimination: the immune system completely eliminates growing tumors.
- Equilibrium: the cancer cells that survive elimination replicate with new variants, making something more resistant to the immune response. Tumors in this phase may revert to elimination or progress to the next phase.
- Escape: cancer cells escape the immune system and are replicated, leading to clinically detectable tumors.
Some ways in which immune escape may be facilitated include the immune system not recognizing tumor cells, the tumor microenvironment leading to increase immunosuppression, or the cancer cells becoming resistant to immune system attacks.