Purpose: Pancreatic cancers are resistant to radiotherapy (RT) and current chemotherapy agents. Epidermal growth factor receptor is overexpressed in pancreatic cancer, and in vitro studies have shown that epidermal growth factor receptor inhibitors can overcome radio- and chemoresistance. The aim of the study was to determine whether the addition of gefitinib to RT and gemcitabine for patients with locally advanced pancreatic carcinoma (LAPC) was feasible and safe.
Methods and materials: Eighteen patients with pathologically proven LAPC, based on major vascular invasion based on helical computed tomography (CT) and endoscopic ultrasound, were entered into the study. The targeted irradiated volume included the tumor and 2-cm margin. Prophylactic irradiation of regional nodes was not allowed. Patients with >500 cm(3) of planning tumor volume were excluded. An initial cohort of 6 patients was treated with RT (45 Gy/25 fractions/5 weeks) plus concomitant gefitinib (250 mg/day). Successive cohorts of patients received 100, 150, and 200 mg/m(2)/day of gemcitabine in a 2-h infusion over Weeks 1, 2, 3, 4, and 5 with gefitinib (250 mg/day) and RT. Gefitinib was continued after RT until progression. A pharmacodynamic study of angiogenic markers was also performed to evaluate a possible antiangiogenic effect.
Results: There were no dose-limiting toxicities. Common toxicities were mild neutropenia, asthenia, diarrhea, cutaneous rash and nausea/vomiting. The median (95% confidence interval [CI]) progression-free survival was 3.7 (95% CI = 1.9-5.5) months, and the median overall survival was 7.5 (95% CI = 5.2-9.9) months. No significant reduction of vascular endothelial growth factor and interleukin-8 was observed after treatment.
Conclusion: Our results support that the combination of gefitinib, RT, and gemcitabine has an acceptable toxicity but with modest activity in LAPC.