Results and patterns of failure in patients treated with adjuvant combined chemoradiation therapy for resected pancreatic adenocarcinoma.

BACKGROUND: Although adjuvant chemoradiation is used commonly in the United States for the treatment of resected pancreatic cancer, there is no consensus on the benefit of this therapy, because the results from randomized trials are conflicting. The authors of this report reviewed their experience in a consecutive, unselected series of patients who received adjuvant 5-fluorouracil (5-FU) and radiation therapy (RT) for resected pancreatic adenocarcinoma.
METHODS: Eighty-six patients with resected pancreatic adenocarcinoma who received adjuvant therapy from 1998 to 2005 were identified, and their medical records were reviewed. Ninety-three percent of patients were treated with external beam RT to > or =50.4 grays, and 91% of patients received concurrent 5-FU by continuous infusion. Forty-five percent of patients went on to receive adjuvant gemcitabine.
RESULTS: The median follow-up was 31 months (range, 21-62 months) among the 20 patients who remained alive. Less than half of patients had positive (33%) or close (<1 mm; 15%) resection margins, 81% of tumors were classified as T3, and 66% of patients had involved lymph nodes. The median overall survival (OS) for all patients was 22 months. Negative lymph node status (P = .016) was a significant prognostic factor for improved OS, whereas treatment with gemcitabine trended toward improved OS (P = .080). The median disease-free survival (DFS) for all patients was 10 months: Treatment with gemcitabine (P = .044) and the receipt of any chemotherapy (P = .047) were significant predictors of DFS. Seventy-five patients (87%) had disease recurrence, and the majority recurred with peritoneal metastases (55%) or liver metastases (53%). Patients who had negative lymph nodes trended toward a lower rate of distant failure (P = .060).
CONCLUSIONS: The median survival of the current cohort was greater than that of the chemoradiation arms of European Organization for Research and Treatment of Cancer trials and European Study Group for Pancreatic Cancer 1 trials and was comparable to the survival observed on the Gastrointestinal Tumor Study Group chemoradiation arm. Lymph node status and treatment with adjuvant chemotherapy were significant predictors of OS and DFS, respectively. Future survival improvements should be directed at reducing peritoneal and liver metastases. Further randomized trials will be required to define the role of adjuvant therapy for pancreatic adenocarcinoma.