Chemoradiation for pancreatic and biliary cancer: current status of RTOG studies

Chemoradiation for gastrointestinal cancers is actively under study in the Radiation Therapy Oncology Group (RTOG) and consists of external irradiation combined with simultaneously administered chemotherapy given to provide radiation sensitization and to attack micro metastatic disease. Two national protocols for the treatment of patients with pancreatic and biliary cancers are now active. RTOG 97-04 is a phase III post-operative combined modality program for patients with resected pancreatic cancer. All patients receive protracted infusional 5-fluorouracil (5-FU) combined with 50.4 Gy given in 28 fractions. Prior to and after chemoradiation all patients are randomized to receive multiple cycles of either infusional 5-FU or Gemcitabine to determine the effect on survival. In the other study (RTOG 98-12) patients with unresectable pancreatic cancer are given 50.4 Gy combined with weekly Paclitaxel (50 mg/m2) to examine the efficacy of this active combination in a phase II trial in a multi-institutional setting. Both of these trials have recently been opened to accrual. A third RTOG study for patients with biliary cancer will examine the efficacy of giving pre-operative chronomodulated infusional 5-FU chemoradiation. The background and the rationale for these studies is based on the long history of 5-FU radiation sensitization in the treatment of cancers of these anatomic sites and will be summarized. A brief review of recently published trials using chemoradiation in conjunction with new irradiation treatment techniques "3D" conformal therapy for these diseases will be discussed.