Fluorouracil-based chemoradiation with either gemcitabine or fluorouracil chemotherapy after resection of pancreatic adenocarcinoma: 5-year analysis of the U.S. Intergroup/RTOG 9704 phase III trial

Abstract

Background: The impact of the addition of gemcitabine to 5-fluorouracil (5-FU) chemoradiation (CRT) on 5-year overall survival (OS) in resected pancreatic adenocarcinoma are presented with updated results of a phase III trial.

Methods: After resection of pancreatic adenocarcinoma, patients were randomized to pre- and post-CRT 5-FU versus pre- and post-CRT gemcitabine. 5-FU was provided continuously at 250 mg/m(2)/day, and gemcitabine was provided at 1000 mg/m(2) weekly. Both were provided over 3 weeks before and 12 weeks after CRT. CRT was provided at 50.4 Gy with continuously provided 5-FU. The primary end point was survival for all patients and for patients with tumor of the pancreatic head.

Results: Four hundred fifty-one patients were eligible. Univariate analysis showed no difference in OS. Pancreatic head tumor patients (n = 388) had a median survival and 5-year OS of 20.5 months and 22% with gemcitabine versus 17.1 months and 18% with 5-FU. On multivariate analysis, patients on the gemcitabine arm with pancreatic head tumors experienced a trend toward improved OS (P = 0.08). First site of relapse local recurrence in 28% of patients versus distant relapse in 73%.

Conclusions: The sequencing of 5-FU CRT with gemcitabine as done in this trial is not associated with a statistically significant improvement in OS. Despite local recurrence being approximately half of that reported in previous adjuvant trials, distant disease relapse still occurs in ≥ 70% of patients. These findings serve as the basis for the recently activated EORTC/U.S. Intergroup RTOG 0848 phase III adjuvant trial evaluating the impact of CRT after completion of a full course of gemcitabine.

Figures

Figure 1A

Overall survival among all eligible patients, according to treatment group assignment. No significant difference between treatment arms was observed.

Figure 1B

Overall survival among all eligible patients with pancreatic head tumors, according to treatment group assignment. Patients had a median and 5-year survival of 20.5 months and 22% in the gemcitabine arm vs. 17.1 months and 18% in the 5-FU arm (p=0.12, HR=0.84, 95%CI (0.67 -1.05).

Figure 2

Schema for RTOG 0848: A Phase III Trial Evaluating Both Erlotinib and Chemoradiation as Adjuvant Treatment for Patients with Resected Head of Pancreas Adenocarcinoma