Background
GITSG 9173. Phase III RCT enrolled 43 patients with pancreatic adenocarcinoma after R0 resection, testing adjuvant chemoradiation versus observation. The trial closed early due to slow accrual.
Interventions and follow up
Arm A: Chemoradiation — RT 40 Gy (split course) with 5-FU 500 mg/m² on the first and last 3 days of RT, followed by maintenance 5-FU 500 mg/m² D1-3 monthly for up to 2 years
Arm B: Observation (surgery alone)
Primary endpoint: Overall survival (and disease-free survival)
mFollow up: NR
Arm B: Observation (surgery alone)
Primary endpoint: Overall survival (and disease-free survival)
mFollow up: NR
Results
mOS: 20 mo vs 11 mo (arm A vs B), P=.03
mDFS: 11 mo vs 9 mo, P=.01
1-yr OS: 63% vs 49%
2-yr OS: 42% vs 15%
mDFS: 11 mo vs 9 mo, P=.01
1-yr OS: 63% vs 49%
2-yr OS: 42% vs 15%
Adverse events
Hematologic: Leukopenia reported with 5-FU/RT (not formally graded by modern criteria, NR)
GI/constitutional: Nausea, vomiting, and diarrhea common; toxicity deemed acceptable with no unexpected treatment-related deaths
GI/constitutional: Nausea, vomiting, and diarrhea common; toxicity deemed acceptable with no unexpected treatment-related deaths
Conclusions
First randomized trial to show a survival benefit from adjuvant 5-FU-based chemoradiation after R0 resection of pancreatic cancer, establishing a role for postoperative adjuvant therapy.
Key Limitations
Very small sample (n=43); closed early for poor accrual; split-course RT and bolus 5-FU now outdated; the role of the radiotherapy component remains contested by later European trials (ESPAC-1, EORTC) favoring chemotherapy alone.
Clinical Context
Historic foundation for adjuvant therapy in resected pancreatic cancer. Subsequent trials reshaped standards: ESPAC-1 favored chemotherapy over chemoradiation, and modern adjuvant care (PRODIGE-24/mFOLFIRINOX, ESPAC-4 gemcitabine/capecitabine) is chemotherapy-based per ESMO/ASCO guidance.