Oxidative stress in the tumor microenvironment in gastric cancer and its potential role in immunotherapy

Gastric cancer (GC) is the fourth leading cause of cancer-related death and the fifth most common malignant tumor globally. However, the clinical efficacy of conventional therapies is limited. Currently, immunotherapy is considered an effective therapeutic strategy for the management of various cancers, especially GC, but is of only limited benefit for GC patients. Accumulating evidence has revealed that oxidative stress plays a critical role in the regulation of immune responses within the tumor microenvironment (TME), affecting the efficacy of immunotherapies. Reactive oxygen species exert critical roles in enhancing antigen presentation, regulating immune responses, and preventing immunoescape. In this review, we summarize the dominant cancer immunotherapeutic strategies and describe the interaction between oxidative stress and the immune TME. We emphasize the underlying mechanisms of the efficacy of cancer immunotherapy, which involves its effects on oxidative stress, in the context of GC. We also highlight the therapeutic potential of regulating oxidative stress to improve immunotherapies, which may have benefits for clinical practice.