The Potential use of Dendritic Cell-based Immunotherapy for Treatment of Pancreatic Cancer

Pancreatic cancers are classified as either exocrine or endocrine tumors depending on which type of tissue they arise from within the gland. Endocrine tumors of the pancreas are very rare, accounting for only 5% of all pancreatic cancers. The majority of endocrine pancreatic tumors are functional adenocarcinomas that overproduce a specific hormone. Pancreatic cancer is a devastating disease and has an extremely poor prognosis. Most patients die within a year of diagnosis and the overall 5-year survival rate is <1% despite the use of extensive treatment approaches, including surgery, chemotherapy, and radiation. Therefore, innovative anti-tumor therapies for this group of patients is of a great significance. Recent preclinical and clinical studies demonstrated that immunotherapy, in particular vaccination with dendritic cells (DCs) loaded with tumor antigens, is a potential approach with promising anti-tumor effects. Therefore, augmenting the efficacy of immunotherapy with DCs would significantly improve the health of this group of patients. One strategy to augment DC-based vaccination is the use of potent adjuvants that can induce the full activation and maturation of the injected antigen-loaded DCs and their migration to the tumor draining lymph nodes, the site of antigen recognition by T cells. One of the most potent adjuvants is the microbial products that are recognized by more than 13 toll-like receptors expressed on DCs. This review article will highlight the use of DC-based vaccination toward pancreatic cancer and how it can be augmented by toll-like receptor agonists.