Gemcitabine and Radiation Therapy Compared With Gemcitabine Alone in Treating Patients Who Have Undergone Surgery for Pancreatic Cancer

OBJECTIVES: Phase II: * Determine the feasibility of gemcitabine followed by chemoradiotherapy with gemcitabine vs gemcitabine alone after prior curative resection in patients with pancreatic head adenocarcinoma. * Compare the tolerability of these regimens, in terms of acute and late toxicity, in these patients. Phase III: * Compare the disease-free and overall survival of patients treated with these regimens . * Compare the quality of life of patients treated with these regimens. * Compare the toxicity of these regimens in these patients. * Determine the sites of recurrence in patients treated with these regimens. OUTLINE: This is a randomized, multicenter study. Patients are stratified according to ECOG/WHO performance status (0-1 vs 2), participating center, and N stage (N0 vs N1 vs NX). Patients are randomized to 1 of 2 treatment arms. * Arm I: Within 8 weeks after prior surgical resection, patients receive gemcitabine IV over 30 minutes on days 1, 8, and 15. Treatment repeats every 4 weeks for 2 courses. Patients then receive additional gemcitabine IV over 30 minutes on days 57, 64, 71, 78, 85, and 92. Beginning on day 57, patients also undergo radiotherapy once daily, 5 days a week, for 6 weeks. Treatment continues in the absence of disease progression or unacceptable toxicity. * Arm II: Patients receive gemcitabine IV over 30 minutes on days 1, 8, and 15. Treatment repeats every 4 weeks for 4 courses. Quality of life (QOL) is assessed in both arms, according to the following schedules: * Arm I: QOL is assessed at baseline; at 3 weeks after the beginning of chemoradiotherapy; after the completion of chemoradiotherapy; every 3 months for 2 years; and then every 6 months for 1 year. * Arm II: QOL is assessed at baseline; at 12 weeks; at 16 weeks; every 3 months for 2 years; and then every 6 months for 1 year. Patients are followed every 3 months for 2 years and then every 6 months thereafter. PROJECTED ACCRUAL: A total of 538 patients (269 per treatment arm) will be accrued for this study within 3 years.