Abstract: Pancreatic cancer is a highly malignant disease in the digestive system.So far,surgical resection is still the primary treatment for pancreatic cancer,but only about 20% of pancreatic cancer patients can be treated with surgery.Even with comprehensive treatment measures such as surgery,radiotherapy and chemotherapy,biological therapy,and targeted therapy,the overall survival rate of pancreatic cancer patients has not been significantly improved in the past ten years.In recent years,immunotherapy has made breakthroughs in tumor treatment.Cancer immunotherapy has now been recognized as the fourth pillar of cancer treatment alongside surgery,radiotherapy,and chemotherapy.There are also many studies in the treatment of pancreatic cancer,but the results are not satisfactory.This article reviews the current status and possible prospects of immunotherapy for pancreatic cancer.

Key words: pancreatic cancer, immune microenvironment, immune checkpoint inhibitor, oncolytic virus, exosomes