140P - Oral cavity immune response in pancreatic ductal adenocarcinoma (PDAC)

Abstract

Background: We studied the humoral immune response in patients with pancreatic ductal adenocarcinoma (PDAC) using mouthwashes from the oral cavity. We found lower immune response against recall antigens, fusobacterium nucleatum and tumor associated antigens before immunotherapy treatment. We also found better prognosis when the antibodies against tested antigens got higher. Finally, we found significant differences in the humoral immune response in the oral cavity against serum. Methods: Antigens from fusobacterium nucleatum, recall and tumor associated antigens were tested by IgG + IgM + IgA ELISA in both oral cavity and serum of PDAC patients n = 50. We provided 5 ml of saline solution to all the patients and controls to rinse the oral cavity hardly for 5 minutes and deposit the content in 15 ml tube. Sera were obtained. All was done after the approval of the local IRB committee. Results: All the evaluated antigens were lower in the oral cavity of PDAC patients compared with controls (p = 0.001). Serum responses for all antigens were significantly different than oral cavity (p = 0.03). At the end of the immunotherapy treatment consisting in a combination of immunomodulation, multi peptide antigen specific active immunotherapy and immunogenic chemotherapy with doxorubicin and oxaliplatin the levels of antibodies were increased significantly. For example, FAP (p = 0.0001), EGFR (p = 0.005), Fascin-1 (p = 0001), VCP (P = 001). Also, the immunotherapy combination significantly increased antibody immune response against fusobaterium lysate (p = 0001). Conclusions: PDAC is a challenge disease especially in late stages. PDAC patients had low antibody titters against several antigens in comparison with controls and before treatment the oral cavity. Serum antibodies were lower than oral cavity even after treatment. Oral cavity antibodies may be a useful early biomarker in patients in high risk of PDAC. This data also suggest that antibodies get low when the cancer or premalignant lesions of PDAC are present. Legal entity responsible for the study: Centro de Investigacion de Cancer en Sonora (CICS). Funding: CICS USA. Disclosure: All authors have declared no conflicts of interest.