Gemcitabine/cisplatin versus 5-fluorouracil/mitomycin C chemoradiotherapy in locally advanced pancreatic cancer: a retrospective analysis of 93 patients

BACKGROUND: Despite of a growing number of gemcitabine based chemoradiotherapy studies in locally advanced pancreatic cancer (LAPC), 5-fluorouracil based regimens are still regarded to be standard and the debate of superiority between the two drugs is going on. The aim of this retrospective analysis was to evaluate the effect of two concurrent chemoradiotherapy regimens using 5-fluorouracil or gemcitabine to compare their effect and tolerance. METHODS: We have performed a single centre retrospective analysis of 93 patients treated with conventionally fractionated radiotherapy of 55.8 Gray using either concurrent 5-fluorouracil, 1 g/m² on days 1-5 and 29-33 of radiotherapy and 10 mg/m² of mitomycin C on day 1, 29 of radiotherapy (FM group, 35 patients) versus gemcitabine (300 mg/m²) and cisplatin, (30 mg/m²) on days 1, 8, 22, and 29 (GC group, 58 patients). Primary endpoint was the median overall survival (OS) rate. RESULTS: The median OS rate was 12.7 months in the GC group and 9.7 months in the FM group. The 1-year OS rate was 53% versus 40%, respectively (p = 0.009). GC led to more grade 3 leukocytopenia and thrombocytopenia than FM, but not to more grade 4 myelosuppression. Thrombocytopenia was the most frequently observed grade 4 toxicity in both groups (11% after FM versus 12% after GC). No grade 3/4 febrile neutropenia was observed. Grade 3 nausea was more common in the FM group (20% versus 9%) and grade 4 nausea was observed in one patient per group only. CONCLUSIONS: GC was superior to FM for overall survival and both regimens were similar in terms of tolerance. We conclude that GC leads to encouraging results and that the use of FM for chemoradiotherapy in LAPC cannot be recommended without concerns.