Immune Checkpoint Inhibitors PD-1/PDL-1 and CTLA-4 as a Novel Solution in Breast Cancer Treatment: A Review Study

Using the immune system responses opens new horizons for cancer treatment. Immune checkpoints are receptors on the surface of cells that prevent the immune response against self-antigens. Cancer cells overexpress these receptors to avoid the immune system's response against them. CTLA-4 and PDL-1/PD1 are examples of immune checkpoints that are expressed on breast cancer cells. PDL-1 expression on breast cancer cells is associated with larger size, progression, more differentiated tumor, which is inversely related to the patient's survival rate. But by inhibiting this pathway with drugs such as Atezolizumab or Ipilimumab, it is possible to inhibit the escape mechanism of tumor cells from the immune system.

Medicines such as checkpoint inhibitors that activate the immune system to face tumors are a new way to help treat breast cancer. In cases where the usual treatment instructions do not have a suitable response, it is possible to improve the survival of patients by adding this family of drugs in the treatment process and considering the side effects as well as their effectiveness.