Prostate cancer (PCa) is the most common noncutaneous
cancer diagnosis and the second leading cause of
cancer-related deaths among men in the United States. Effective treatment modalities for advanced metastatic PCa are limited. Immunotherapeutic strategies based on T cells and
antibodies represent interesting approaches to prevent progression from localized to advanced PCa and to improve survival outcomes for patients with advanced disease. CD8+ cytotoxic T lymphocytes (CTLs) efficiently recognize and destroy
tumor cells. CD4+ T cells augment the
antigen-presenting capacity of dendritic cells and promote the expansion of
tumor-reactive CTLs.
Antibodies mediate their antitumor effects via antibody-dependent cellular cytotoxicity, activation of the
complement system, improving the uptake of coated
tumor cells by phagocytes, and the functional interference of biological pathways essential for
tumor growth. Consequently, several
tumor-associated
antigens (TAAs) have been identified that represent promising targets for T cell- or antibody-based
immunotherapy. These TAAs comprise
proteins preferentially expressed in normal and malignant prostate tissues and molecules which are not predominantly restricted to the prostate, but are overexpressed in various
tumor entities including PCa. Clinical trials provide evidence that specific immunotherapeutic strategies using such TAAs represent safe and feasible concepts for the induction of immunological and clinical responses in PCa patients. However, further improvement of the current approaches is required which may be achieved by combining T cell- and/or antibody-based strategies with radio-,
hormone-, chemo- or antiangiogenic
therapy.