The immune system, protects our body against infections and diseases. In fact, the immune system is a very effective defense mechanism against cancer. In addition, cancer is a cell with a very complex structure that can escape from the immune system.
Cancer immunotherapy is used as drugs or methods that can direct the immune system so that the immune system cells can recognize and destroy cancer cells.
Normally, immune system cells find and destroy abnormal cells. To a large extent, they can find and destroy cancer cells. However, when cancer cells can escape from the immune system, they can cause disease. In many cancer types, lymphocytes have been detected around cancer cells in pathological examinations. These lymphocytes are called lymphocytes that can enter the tumor area (TIL). The presence of TIL cells basically means that lymphocytes, one of our most important fighters, can recognize cancer cells and take action to prevent them. The higher the amount of TIL in the tumor tissue, the better the course of the cancer is usually.
Genetic changes in cancer cells can cause them to escape from the immune system more easily.
Proteins (PD-L1) on the surfaces of cancer cells can prevent immune system cells from recognizing them.
In addition, some immune system cells (such as T regulator, Treg) can prevent other cells of the immune system from being effective against cancer.
At this point, immunotherapy drugs are drugs that enable immune cells (such as T cells, NK cells, macrophages) effective against cancer to be effective against cancer by detecting cancer cells.
Before deciding on immunotherapy in cancer, a decision should be made by performing comprehensive genomic profiling. Genetic changes in cancer are one of the main determinants in the design and decision of immunotherapy. Immunotherapy decisions based on only PD-L1 or a few markers can be incomplete and inadequate. In particular, comprehensive genomik profiling is required for decisions to be made by determining the tumor mutation burden.
The most important immunotherapy drugs today are drugs that block PD-L1, PD-1 and CTL4 proteins. In short, these drugs are called immune checkpoint inhibitors.
• PD-L1 status
• Presence and proportions of immune cells in tumor tissue
• Parameters indicating that the tumor is detected more easily by immune cells (MSI, microsatellite instability status; TMB, tumor mutation burden)
• Mutations showing resistance to immunotherapy (such as PTEN, STK11. Important data are available, although at the research stage.)
• Mutations showing that immunotherapy may be more effective (such as ARID1A, POLE/POLD1, PBRM1. Although there is important evidence about these data, they are still in the research phase.)
