Low-Dose Radiotherapy to Preserve Immunotherapy Delivery in Breast Cancer Patients at High Risk for Immune-Mediated Arthritis (PRAISE-BC)
Immune checkpoint inhibitors are immunotherapy drugs that help the immune system attack breast cancer. A growing number of patients with breast cancer stay on these drugs for one to two years to keep the cancer under control. While this can improve survival, it also raises the chance of immune side effects including sudden joint inflammation, which can cause pain, stiffness and difficulty walking, particularly in joints already affected by osteoarthritis. These flares may require pausing immunotherapy and taking steroids or other immune-suppressing medications. Our research is evaluating a novel approach to managing this side effect using low-dose radiotherapy, a local treatment designed to calm the inflamed joint without suppressing the whole immune system. In a clinical trial, patients who have experienced a flare will receive low-dose radiotherapy to the affected joint after the flare improves and before restarting immunotherapy. In addition to measuring whether flares return, how pain and function change, and how well patients can stay on immunotherapy, we will study changes in immune cells, inflammatory signals in blood and joint fluid, and MRI scans of the affected joint before and after radiotherapy to better understand who benefits most from this treatment. Ultimately, this work aims to reduce side effects, minimize steroid use and help more patients with breast cancer successfully complete life-saving immunotherapy.
