Circulating CD8 + CD122 + T cells as a prognostic indicator of pancreatic cancer

Purpose: The role of peripheral immunosuppressive cells in pancreatic cancer prognosis remains debated. The purpose of this study was to analyze the peripheral levels of CD4 + and CD8 + CD122 + T cells, and establish their association with the prognosis of pancreatic cancer patients. Methods: : Blood and tissue samples were collected from patients with metastatic pancreatic cancer (n=54), resectable pancreatic cancer (n=12), and benign pancreatic cysts (n=52) between April 2019 and January 2022 and analyzed. Results: : Patients with metastatic pancreatic cancer had a larger proportion of both tumor-suppressive and tumor-promoting cells than those with benign pancreatic cysts. In addition, the proportion of peripheral CD4 + T cells positively correlated with the survival of patients with metastatic pancreatic cancer, and the proportion of peripheral CD8 + CD122 + T cells was associated with early mortality (<90 days). After chemotherapy, CD8 + CD122 + T cells decreased in patients who had a partial response or stable disease. Moreover, by analyzing resected specimens, we first proved that the existence of CD8 + CD122 + T cells in a tumor microenvironment (TME) depends on their proportion in peripheral blood. Conclusion: Circulating CD8 + CD122 + T cells can be a prognostic indicator in patients with pancreatic cancer, and may play a suppressive role against other effector T cells in the TME.