Immunotherapeutic approaches in pancreatic cancer

Postoperative Gemcitabine Alone and Concurrent with Radiation Therapy in Locally Advanced Pancreatic Carcinoma

Aims and background

To evaluate the treatment results of gemcitabine alone and concurrent with radiotherapy after R0/R1 resection of locally advanced pancreatic cancer.

Methods and study design

From 1999 to 2005, 55 patients with stage II resected pancreatic cancer treated with gemcitabine-based radiochemotherapy were retrospectively evaluated. Initially, one cycle of induction gemcitabine was administered and followed by weekly gemcitabine concurrent with radiotherapy. After the completion of radiochemotherapy, patients received 3 additional courses of gemcitabine.

Results

Thirteen patients were stage IIA and 42 were stage IIB. Forty-six patients (83.6%) had R0 and 9 patients (16.4%) had R1 resection. All of the patients received induction chemotherapy and radiotherapy, all but 3 received concurrent radiochemotherapy, and 46 (84%) patients received maintenance chemotherapy. During induction, concurrent and maintenance phases of the protocol, 11%, 13.5% and 19.5% of the patients had at least one ≥grade 3 toxicity, respectively. Within a median 47 months (range, 34–105) of follow-up, 4 (7.3%) patients had isolated local recurrence, 5 (9%) patients had local recurrence and distant metastases, and 27 (49%) had only distant metastases. Median disease-free survival and overall survival were 13 (range, 4-105) and 19 months (range, 6-105), respectively. In multivariate analysis, nodal stage, AJCC stage and number of lymph nodes dissected were the significant factors affecting disease-free survival whereas Karnofsky performance status was the only significant factor for overall survival.

Conclusions

The prognosis for pancreatic cancer remains poor despite adjuvant radiochemotherapy. More aggressive treatments should be considered in patients with unfavorable prognostic factors.

Progression of pancreatic adenocarcinoma is significantly impeded with a combination of vaccine and COX-2 inhibition

With a 5-year survival rate of <5%, pancreatic cancer is one of the most rapidly fatal malignancies. Current protocols for the treatment of pancreas cancer are not as effective as we desire. In this study, we show that a novel Mucin-1 (MUC1)-based vaccine in combination with a cyclooxygenase-2 inhibitor (celecoxib), and low-dose chemotherapy (gemcitabine) was effective in preventing the progression of preneoplastic intraepithelial lesions to invasive pancreatic ductal adenocarcinomas. The study was conducted in an appropriate triple transgenic model of spontaneous pancreatic cancer induced by the KRAS(G12D) mutation and that expresses human MUC1 as a self molecule. The combination treatment elicited robust antitumor cellular and humoral immune responses and was associated with increased apoptosis in the tumor. The mechanism for the increased immune response was attributed to the down-regulation of circulating prostaglandin E(2) and indoleamine 2, 3,-dioxygenase enzymatic activity, as well as decreased levels of T regulatory and myeloid suppressor cells within the tumor microenvironment. The preclinical data provide the rationale to design clinical trials with a combination of MUC1-based vaccine, celecoxib, and gemcitabine for the treatment of pancreatic cancer.