The Role of Circulating Dendritic Cells in Patients with Unresectable Pancreatic Cancer

Aim: Pancreatic cancer is a malignant neoplasm with a poor prognosis that might be associated with defective immune function. In this study, we aimed to clarify the role of circulating in dendritic cells (cmDCs) and lymphoid (el) DCs in patients with unresectable pancreatic cancer. Patients and Methods: This study covered the period from January 2001 to December 2009, and involved 104 patients with unresectable pancreatic cancer. We measured the number of cmDCs and clDCs using flow cytometry before and after chemotherapy, chemoradiotherapy and immuno-chemotherapy. Results: The percentage of the cmDC subset in the unresectable pancreatic cancer patients was significantly lower than in healthy volunteers (p=0.006). There was no difference in the cmDC subset between patients with distant organ metastasis and locally advanced pancreatic cancer. The patients with a high percentage (>= 0.23%) of cmDC subset survived longer than patients with a low percentage (<0.23%) (p=0.0030). Multivariate analysis showed that cmDC was the only independent prognostic factor (p=0.0059). The percentage of cmDC subset was significantly increased after immuno-chemotherapy (p=0.0055). Conclusion: A high level of cmDCs is associated with better survival rate and is an independently favorable prognostic factor in patients with unresectable pancreatic cancer. It is likely that immuno-chemotherapy increases the number of cmDCs.