Full-dose gemcitabine is a more effective chemotherapeutic agent than 5-fluorouracil for concurrent chemoradiotherapy as first-line treatment of locally advanced pancreatic cancer

Abstract

Objectives: To compare the therapeutic efficacy and tolerability of full-dose gemcitabine-based CCRT (FG-CCRT) and conventional 5-FU-based CCRT (5FU-CCRT) for locally advanced pancreatic cancer (LAPC).Methods: From January 2006 to March 2013, 109 patient cases of LAPC treated with FG-CCRT (n=89) or 5FU-CCRT (n=20) were reviewed retrospectively. The FG-CCRT group was composed of a full-dose weekly gemcitabine monotherapy (1000mg/m2) arm and a full-dose gemcitabine and cisplatin (70mg/m2) combination arm. The 5FU-CCRT group was treated with a radiosensitizing bolus dose of 5-FU (500mg/m2, weekly) plus leucovorin (20mg/m2, weekly). In both groups, concurrent radiotherapy was targeted at the primary tumor with a 5 mm margin without lymph node irradiation.Results: Objective response rate (ORR) and disease control rate (DCR) was significantly higher in the FG-CCRT group (ORR – 32.6% vs. 5%; P = 0.013; DCR – 79.8% vs. 50.0%; P = 0.006). Additionally, FG-CCRT showed remarkable superiority to 5FU-CCRT for the control of distant metastasis (18.0% vs. 45.0%; P = 0.017). Both groups showed similar loco-regional control rates (93.3% vs. 85.0%; P = 0.362). With regards to toxicity, grade 3 or higher neutropenia (34.8% vs. 10%; P = 0.032) and thrombocytopenia (21.3% vs. 0.0%; P = 0.021) were more frequent in the FG-CCRT group as originally expected. In a subgroup analysis, toxicities of the full-dose gemcitabine monotherapy-based CCRT group were not different than those of the 5FU-CCRT group.Conclusion: FG-CCRT, especially full-dose gemcitabine monotherapy-based CCRT, was more effective for the initial control of LAPC than 5FU-CCRT and can be used without concerns of increasing toxicity.