Immunotherapeutic approaches in pancreatic cancer.

With growing understanding of the regulation of immune responses, multiple new immunotherapeutic targets have evolved. This article gives a survey over the current approaches in pancreatic cancer therapy including peptide vaccinations, unspecific immunotherapy, allogene modified tumor cell vaccines, and vector-based vaccines. Although several trials have shown detectable immune responses, such as delayed-type hypersensitivity reactions and cytokine release in enzyme-linked immunosorbent spot (ELISPOTS) assays, and some have reported prolonged survival for immune responders, immunotherapy remains experimental. However, some approaches have made it into a phase III setting. In addition, the emerging concept of tumor stem cells may lead to a new focus on immunotherapy, since these often highly chemotherapy-resistant cells are thought to be the source of recurrences.