Current and emerging perspectives on immunotherapy for pancreatic cancer

Pancreatic cancer (PC) is an extremely lethal disease and despite significant advances in cancer therapy, including chemotherapy, radiation, surgery, or targeted therapy, the current treatment strategies remain insufficient to cure PC patients due to the development of chemoresistance of pancreatic tumors. The ineffective nature of these strategies highlights the need for a better approach to improve patients’ survival. This need for better treatment has prompted the rise of immunotherapy in PC treatment. Specifically, these types of therapy have sought to attack the tumor’s defense mechanisms while simultaneously inducing an immune response that would be used to eradicate the tumor itself. In PC, increased T-regulatory cells, myeloid derived suppressor cells and tumor associated macrophages while reduced cytotoxic T-cells and natural killer (NK) cells establish an immunosuppressive environment. A recent publication by Zhang et al. highlights the specific pathways by which myeloid cells suppress immune response, and how the reduction of these cells can induce regression of the tumor itself. They also suggest how a combined therapeutic regimen of mitogen-activated protein kinases (MAPK) inhibition with immunotherapy modulates different immunosuppressive pathways. In this perspective, we will also discuss recent achievements in the immunotherapy for PC.