Radiotherapy as a partner for immunotherapy in pancreatic cancer: current landscape and future directions

Pancreatic ductal adenocarcinoma (PDAC) continues to rise in incidence and remains one of the deadliest solid tumors due to its insidious onset and extremely poor overall survival. Current therapeutic options-surgery, chemotherapy, and radiotherapy-offer limited benefit for most patients, largely because of the tumor's dense stromal architecture, profoundly immunosuppressive microenvironment, and inherent resistance to conventional treatments. In recent years, advances in immune checkpoint inhibitors (ICIs), cancer vaccines, oncolytic viruses, and adoptive cell therapies have driven steady progress in the field of PDAC immunotherapy. At the same time, multimodal strategies that combine immunotherapy with radiotherapy, targeted agents, or chemotherapy have begun to show promising synergistic activity. This review summarizes the recent developments in both single-agent and combination immunotherapeutic approaches for PDAC, and highlights the key challenges and future directions for improving treatment outcomes.