Long-term survival of pancreatic cancer patients treated with multimodal therapy combined with WT1-targeted dendritic cell vaccines

Background/Aim: Pancreatic ductal adenocarcinoma (PDA) remains one of the most aggressive tumors with a dismally poor prognosis. Although surgical resection remains the only potentially curative treatment, most PDAs are not surgically resectable at diagnosis. Therefore, multimodal therapy is urgently needed to improve the long-term survival of PDA patients. Methods: Six eligible PDA patients underwent multimodal therapy comprising dendritic cells (DCs) pulsed with Wilms' tumor 1 (WT1) peptide (DC/WT1-I) restricted by the human leukocyte antigen (HLA) class I (A*24:02 or A*02:06) allele, chemotherapy, radiation, and/or surgery. Patient laboratory data, DC/WT1-I-specific delayed-type hypersensitivity (DTH) reactions, and WT1-specific immune responses were analyzed to assess the prognostic markers of multimodal therapy. Results: Compared to 2-treatment type combinations, multimodal therapy involving 3 to 4 treatment types was significantly associated with longer overall survival (p = 0.0177). Moreover, after 7 DC/WT1-I vaccinations, the progression-free survival (PFS) of PDA patients with a neutrophil to lymphocyte ratio (NLR) or C-reactive protein (CRP) level less than the median was superior to that of PDA patients with values above the median (p = 0.0246). PDA patients with an overall survival (OS)>1000 days had significantly more lymphocytes after one DC/WT1-I vaccination course than did those with an OS