Tumor Immunology and Cancer Immunotherapy: Mechanisms, Resistance, and Emerging Strategies

This chapter offers an in-depth review of the principles underlying tumor immune surveillance and evasion, encompassing the tumor microenvironment, immunosuppressive cellular networks, and the molecular basis of immune escape. It evaluates current immunotherapeutic modalities — including PD-1/PD-L1 checkpoint inhibition, CAR-T cell therapy, tumor-infiltrating lymphocyte approaches, and cancer vaccines — with a focus on mechanisms of primary and acquired resistance. Emerging combinatorial and personalized strategies to overcome therapeutic limitations and expand the efficacy of cancer immunotherapy are also discussed.