Immunomodulation in Pancreatic Cancer

Simple Summary Pancreatic cancer is an aggressive disease that has few options for treatment. Immune checkpoint blockers have been revolutionary in specific cancer types yet have not shown promise in pancreatic cancers. This review discusses components of the immune system needed for successful anti-tumor responses against pancreatic cancer and how these mechanisms can be exploited to develop new therapeutic strategies. Pancreatic cancer has a high mortality rate, and its incidence is increasing worldwide. The almost universal poor prognosis of pancreatic cancer is partly due to symptoms presenting only at late stages and limited effective treatments. Recently, immune checkpoint blockade inhibitors have drastically improved patient survival in metastatic and advanced settings in certain cancers. Unfortunately, these therapies are ineffective in pancreatic cancer. However, tumor biopsies from long-term survivors of pancreatic cancer are more likely to be infiltrated by cytotoxic T-cells and certain species of bacteria that activate T-cells. These observations suggest that T-cell activation is essential for anti-tumor immunity in pancreatic cancers. This review discusses the immunological mechanisms responsible for effective anti-tumor immunity and how immune-based strategies can be exploited to develop new pancreatic cancer treatments.