Management of Brain Metastases in the New Era of Checkpoint Inhibition

Purpose of the Review Brain metastasis is a common complication of advanced malignancies, especially, lung cancer, breast cancer, renal cell carcinoma, and melanoma. Traditionally surgery, when indicated, and radiation therapy, either as whole-brain radiation therapy or stereotactic radiosurgery, constituted the major treatment options for brain metastases. Until recently, most of the systemic chemotherapy agents had limited activity for brain metastases. However, with the advent of small molecule tyrosine kinase inhibitors and immunotherapy agents, there has been renewed interest in using these agents in the management of brain metastases. Recent Findings Immune checkpoint inhibitors have revolutionized the treatment of metastatic melanoma, lung cancer, kidney cancer, and bladder cancer among others. They modulate the immune system to recognize tumor antigens as “non-self” antigens and mount an immune response against them. Summary Initial studies of using immune checkpoint inhibitors in brain metastases have shown promising activity, and several clinical trials are currently underway. Studies are also assessing the combination of radiation therapy and immunotherapy in brain metastases. The results of these ongoing clinical trials have the potential to change the therapeutic paradigm in patients with brain metastases.