Abstracts
2002 Digestive Disease Week

# 105116 Abstract ID: 105116 Patients Undergoing Treatment for Pancreatic Adenocarcinoma Can Mount an Effective Immune Response to Vaccinations
Jennifer F Tseng, Christopher G Willett, Carlos Fernandez-Del castillo, David P Ryan, Jeffrey W Clark, Andrew X Zhu, David W Rattner, Jennifer L Winkelmann, Andrew L Warshaw, Boston, MA

Background: Immunotherapy has been proposed as a novel treatment for pancreatic cancer. However, patients with pancreatic cancer have been observed to have depressed immune responses. We sought to determine whether patients undergoing treatment for pancreatic adenocarcinoma could mount effective immune responses to standard vaccinations. Methods: We enrolled patients with pancreatic adenocarcinoma scheduled for adjuvant or primary chemotherapy and/or radiation therapy. At the initiation of therapy, patients had an anergy panel placed and baseline blood work performed. During the first week of treatment, patients received tetanus toxoid, Hemophilus influenzae, and pneumococcus vaccines. Twelve weeks after vaccine administration, IgG titers against the 3 administered vaccines were drawn and lymphocyte proliferation assays in response to tetanus toxoid were performed. 95% confidence intervals (CI) were calculated using a binomial distribution. Results: To date, 15 patients have been enrolled. Anergy panel responses are complete for 13 patients; pre- and post-vaccination data are complete for 11 patients. Nine of 13 patients (69% response rate, 95% CI 39-91%) demonstrated >10 mm induration in response to mumps or candida antigen. Eleven of 11 patients (100% response rate, 95% CI 72-100%) demonstrated >3x increase in IgG against one or more vaccines. Seven of 11 patients (64% response rate, 95% CI 31-89%) demonstrated at least a threefold rise of lymphocyte proliferation against tetanus toxoid. Conclusions: Patients with pancreatic cancer appear to be capable of mounting effective cellular and humoral responses to standard vaccines. These data suggest that immunotherapy for pancreatic cancer is a worthwhile area for further investigation.