Abstract
In recent years, immunotherapy represented by programmed death receptor 1 (PD-1) inhibitors has significantly improved the prognosis of patients with gastric cancer, making the immunotherapy of gastric cancer a focus of clinical attention. Although immune checkpoint inhibitors (ICIs) have achieved breakthroughs in immunotherapy, only a portion of patients have achieved promising long-term results in response to checkpoint inhibitors, indicating the existence of other unknown tumor-induced immunosuppressive pathways. The failure of immunotherapy is mainly related to the induction of immune tolerance in the tumor microenvironment of gastric cancer. Therefore, solving the problem of tumor immune tolerance is the key to the success of immunotherapy for gastric cancer. Studies have found that OPN promotes tumor progression through multiple mechanisms such as influencing tumor cell survival, tumor angiogenesis, and regulating the tumor microenvironment. For this purpose, we review the role of OPN in the occurrence and development of gastric adenocarcinoma, and focus on reviewing the current research progress of OPN in inducing immune escape of gastric adenocarcinoma and the synergistic effect between OPN and PD-L1 and its potential mechanisms, laying the foundation for the development of immunotherapy combination methods based on OPN in future.