Phase II study of gemcitabine combined with radiation therapy in patients with localized, unresectable pancreatic cancer

Background and Objectives: Gemcitabine is an active agent in pancreatic cancer, with known radiosensitizing properties. Therefore, a phase II study was conducted to evaluate the efficacy of gemcitabine combined with radiation therapy in patients with localized unresectable adenocarcinoma of the pancreas. Methods: Weekly gemcitabine at a dose of 1,000 mg/m² for 7 weeks was given as an induction phase. Patients who showed both clinical benefit response (CBR) and reduced or stable tumor size on computed tomography (CT) scan entered the chemoradiotherapy phase of the treatment. This consisted of gemcitabine 400 mg/m² weekly × 3 every 28 days for 2 cycles, given concurrently with radiotherapy, for a total dose of 50.4 Gy in 28 fractions. After completion of radiotherapy, gemcitabine was continued as maintenance. Results: Twenty patients entered this study. Ten patients (50%) achieved CBR to gemcitabine in the induction phase; these patients had no objective tumor progression and were therefore enrolled in the chemoradiotherapy phase. Four patients (20%) had a partial response, and three patients (15%) underwent pancreatectomy. Two patients had negative surgical margins, and in one patient histologic examination of the residual mass showed only fibrosis. The median survival for the entire group was 8 months, and the median survival has not yet been reached for the chemoradiotherapy group. Conclusions: Treatment with gemcitabine concomitant with radiation therapy according to the present schedule is well tolerated and can provide prolonged CBR and disease stabilization in patients with localized, unresectable pancreatic cancer.