PD‑1/PD‑L1 immune checkpoint in bone and soft tissue tumors (Review)

Anti‑programmed cell death 1 (PD‑1)/PD‑1 ligand‑1 (PD‑L1) drugs have been used clinically, including those for skin cancer, with reasonable efficacy. Despite extensive ongoing research on bone and soft tissue sarcomas, there is a paucity of reviews that present a coherent picture. The present article is a comprehensive narrative review on the role of the PD‑1/PD‑L1 immune checkpoint in bone and soft tissue tumors. The review outlines the biological functions and mechanisms of action of PD‑1/PD‑L1 and its expression and clinical significance in various tumor types, including osteosarcoma and soft tissue sarcoma. Clinical trial results of immune checkpoint inhibitors, their association with prognosis, mechanisms of resistance to therapy, immune‑related adverse events, and their potential in combination therapies, were also discussed.