Purpose: To present an overview of Phase III trials in adjuvant therapy for pancreatic cancer and review outcomes at the Mayo Clinic after adjuvant radiochemotherapy (RT/CT) for resected pancreatic cancer.
Methods and materials: A literature review and a retrospective review of 472 patients who underwent an R0 resection for T1-3N0-1M0 invasive carcinoma of the pancreas from 1975 to 2005 at the Mayo Clinic, Rochester, MN. Patients with metastatic or unresectable disease at the time of surgery, positive surgical margins, or indolent tumors and those treated with intraoperative radiotherapy were excluded from the analysis. Median radiotherapy dose was 50.4 Gy in 28 fractions, with 98% of patients receiving concurrent 5-fluorouracil- based chemotherapy.
Results: Median follow-up was 2.7 years. Median overall survival (OS) was 1.8 years. Median OS after adjuvant RT/CT was 2.1 vs. 1.6 years for surgery alone (p = 0.001). The 2-y OS was 50% vs. 39%, and 5-y was 28% vs. 17% for patients receiving RT/CT vs. surgery alone. Univariate and multivariate analysis revealed that adverse prognostic factors were positive lymph nodes (risk ratio [RR] 1.3, p < 0.001) and high histologic grade (RR 1.2, p < 0.001). T3 tumor status was found significant on univariate analysis only (RR 1.1, p = 0.07).
Conclusions: Results from recent clinical trials support the use of adjuvant chemotherapy in resected pancreatic cancer. The role of radiochemotherapy in adjuvant treatment of pancreatic cancer remains a topic of debate. Results from the Mayo Clinic suggest improved outcomes after the administration of adjuvant radiochemotherapy after a complete resection of invasive pancreatic malignancies.