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

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. 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/m2/day, and gemcitabine was provided at 1000 mg/m2 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. 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%. 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.