Shedding Light on Cause of Resistance to Tumor Immunotherapy

Cancer is the second most common cause of death worldwide. Until recently, the chances of cure for patients suffering from metastatic cancer were low, as with such cancer the surgical removal of distant metastases in various organs or their local treatment using radiotherapy were usually unsucessful. Likewise, the use of chemotherapy is limited by its toxic systemic side effects. Tumor immunotherapy has been used for several years, with patients with certain metastatic cancers showing good responses to this treatment. These immunotherapies, also called checkpoint inhibitors, allow the body's own immune system to better detect and destroy the cancer cells. The problem is that with time cancer cells become resistant to the triggered immune responses. Now researchers of the University of Zurich and the University Hospital Zurich have discovered a mechanism that plays a central role in the development of this resistance.