Eastern Cooperative Oncology Group Phase I trial of protracted venous infusion fluorouracil plus weekly gemcitabine with concurrent radiation therapy in patients with locally advanced pancreas cancer: a regimen with unexpected early toxicity.

PURPOSE We performed a phase I trial of protracted venous infusion (PVI) fluorouracil (5-FU) plus weekly gemcitabine with concurrent radiation therapy in patients with locally advanced pancreas cancer to determine the maximum-tolerated dose of gemcitabine that could be safely administered. We also sought to identify the toxicities associated with this treatment protocol. PATIENTS AND METHODS Seven patients with locally advanced pancreas cancer were treated with planned doses of radiation (59.4 Gy) and PVI of 5-FU (200 mg/m(2)/d) with gemcitabine doses of 50 to 100 mg/m(2)/wk. RESULTS Two of three patients at the 100-mg/m(2)/wk dose level experienced dose-limiting toxicity (DLT), as did three of four at the 50-mg/m(2)/wk dose level. One patient experienced a mucocutaneous reaction described as a Stevens-Johnson syndrome that was attributed to chemotherapy. Three patients developed gastric or duodenal ulcers with severe bleeding requiring transfusion. One patient developed severe thrombocytopenia lasting longer than 4 weeks. Three of the five episodes of DLT developed at radiation doses < or = 36 Gy. CONCLUSION Based on this experience, we cannot recommend further investigation of regimens incorporating gemcitabine into regimens of radiation with PVI 5-FU. The mechanism of this synergistic toxicity remains to be determined.