A new study finds that immune response in prostate cancer may be able to forecast how patients will respond to radiation therapy, as well as their likelihood of disease recurrence and survival outcomes. The analysis of more than 9,000 prostate tumors also found evidence that PD-L2, not PD-L1, may provide a key route for targeted therapies, such as immunotherapy, to slow disease progression. “When the immune system responds to tumors, it sends specific types of immune cells directly to the tumor. Understanding this infiltration of immune cells allows researchers and oncologists to devise treatment strategies based on each patient’s specific immune response and disease biology. Checkpoint inhibitors and other immunotherapies have been utilized to manage other solid tumors. Our work suggests that there may be a role for these innovative treatments in prostate cancer, as well,” said Shuang Zhao, lead author of the clinical study and a radiation oncology resident at the University of Michigan in Ann Arbor.