Purpose: This phase II trial of induction irinotecan/gemcitabine followed by twice-weekly gemcitabine and upper abdominal radiation was initiated to determine the activity of this regimen in patients with unresectable pancreatic cancer.
Methods: Patients with locally advanced, nonmetastatic adenocarcinoma of the pancreas received 2 cycles of induction irinotecan (100 mg/m2 IV) and gemcitabine (1000 mg/2 IV) on days 1 and 8 of each 3-week cycle. Following the induction, patients without disease progression received gemcitabine administered twice weekly (40 mg/m2/day) for 5 weeks concurrent with upper abdominal radiation (50.4 Gy over 5.5 weeks).
Results: From April 2000 to August 2003, 20 patients were entered into this study, 17 of whom were evaluable for treatment response. Characteristics included a median age of 67 years (range, 44-87 years) and 14 men (70%). Grades III and IV hematologic toxicity occurred in 25% and 5% of patients respectively and was primarily thrombocytopenia. No grade IV gastrointestinal toxicities or deaths due to therapy were observed. All therapy was completed in 8 patients, 7 patients were removed due to progression, 2 due to toxicity, 2 refused further treatment, and 1 was removed per the treating physician. The median time to progression and median survival was 5.1 months (95% CI, 3.2-6.7) and 8.8 months (95% CI, 6.4-10.1) respectively. Four patients (20%) were alive at 12 and 18 months.
Conclusion: Induction irinotecan/gemcitabine followed by twice-weekly gemcitabine and upper abdominal radiation is feasible in patients with locally advanced pancreatic cancer. This regimen, however, has only modest activity and should not be explored further.