Mechanisms, Classifications and Future Trends in Tumor Immunotherapy
: Tumor immunotherapy has fundamentally transformed modern oncology. This approach essentially mobilizes the patient’s own immune defenses to identify and eliminate cancer cells— a strategy that continues to redefine how we treat cancer today.This review traces the history of cancer immunotherapy and explains how the immune system detects and controls tumors — including the ideas of immune surveillance and immunoediting. It also outlines key ways tumors evade immunity. These include PD-1/PD-L1 signal transduction, suppression by regulatory T cells, and how the tumor microenvironment has an immunosuppressive character. Looking ahead, the review emphasizes future directions and explores opportunities for combination treatments. It also discusses the potential of personalized therapies and the development of new strategies. Challenges such as drug resistance, treatment-related side effects, and limited effectiveness in solid tumors are analyzed, with proposed solutions. Research shows that through deeper mechanistic understanding, diverse treatment options, and continuous innovation, tumor immunotherapy brings new hope for long-term disease control and possibly even curing cancer.