Research progress in tumor microenvironment of pancreatic cancer

Pancreatic cancer is an aggressive malignant tumor with poor prognosis. On the one hand, it has a narrow therapeutic window due to the lack of specific markers and obvious clinical symptoms. Once diagnosed, it has often developed to an advanced stage. On the other hand, located in a vital region of the body, pancreatic operation is difficult and the postoperative recurrence rate is high. Therefore, surgical treatment is only sui-table for a small number of early patients. Pancreatic cancer has a tumor microenvironment with the characteristic of dense stroma, hypoxia, paucity of blood vessels and highly immunosuppression. It is often insensitive to traditional radiation and chemotherapy. Therefore, strategies targeting on tumor microenvironment have a potential prospect. This article reviews the research progress in tumor microenvironment of pancreatic cancer, in order to provide the references in the further research and treatment of pancreatic cancer. Key words: Pancreatic neoplasms; Tumor microenvironment; Pancreatic stellate cell; Immunosuppression; Stromal barrier