Oxidative Stress in the Tumor Immune Microenvironment: Mechanisms and Therapeutic Perspectives

ABSTRACT Reactive oxygen species (ROS) play a profoundly central and multifaceted role in orchestrating the complex dynamics of the tumor immune microenvironment (TIME). Oxidative stress, driven by elevated ROS levels, is considered a key regulator of tumor progression, immune cell function, and immune evasion. Although the profound impact of oxidative stress on initial oncogenesis and cellular proliferation is extensively documented, its specific contribution to TIME remodeling and subsequent immune escape warrants further investigation. This review systematically summarizes the core mechanisms of ROS and oxidative stress in the TIME. We elucidate how dysregulated ROS, generated by both malignant tumor cells and infiltrating immune populations, synergistically promote continuous tumor progression, profound local immunosuppression, and pervasive therapy resistance. Specifically, we discuss in detail how sustained oxidative stress critically alters diverse immune cell functions, fundamentally reshaping the TIME landscape, and explore oxidative stress–mediated intercellular communication networks, including metabolic competition and the release of soluble factors. By strategically bridging fundamental redox biology with emerging clinical oncology applications, this review provides novel therapeutic perspectives on modulating redox homeostasis to effectively reverse immunosuppression and bolster anti‐tumor immunity.