[Late phase II trial of high-dose l-leucovorin and 5-fluorouracil in advanced colorectal carcinoma. l-Leucovorin and 5-FU Study Group (Japan Eastern Group)].

A multicenter cooperative study was conducted from Dec. 1992 to April 1994 to evaluate the clinical efficacy of high-dose l-leucovorin (l-LV) and 5-fluorouracil (5-FU) treatment in 76 patients with advanced colorectal carcinoma. Treatment consisted of intravenous bolus injection of 5-FU (600 mg/m2) 1-hour after the initiation of a 2-hour infusion l-LV (250 mg/m2), 6 weekly treatments were administered followed by a two-week rest. These treatment were repeated until progressive disease or intolerable toxicity. Seventy patients were evaluated for response. Responses were the following: PR 21, NC 29, PD 20 and the overall response rate was 30%. Grade 4 hematological side-effect was observed in three cases, and severe diarrhea in one case. These data suggested that high-dose l-LV and 5-FU was effective for advanced colorectal carcinoma but showed some hematological toxicity, and a further investigation should be carried out.