Biochemical modulation of 5-fluorouracil by methotrexate in patients with advanced gastric carcinoma

A phase II trial was conducted to evaluate the efficacy and toxicity of a modulation of 5-fluorouracil (5-FU) by methotrexate (MTX) (with leucovorin (LV) rescue) as first-line chemotherapy in patients with locally advanced (inoperable) or metastatic gastric carcinoma. From July 1993 through August 1996, 36 patients with advanced gastric carcinoma received a regimen that consisted of: MTX 200 mg/m2 diluted in 250 ml normal saline by intravenous infusion over 20 minutes at hour 0; 5-FU 1,200 mg/m2 intravenous push injection at hour 20. Beginning 24 hours after MTX administration all patients received LV 15 mg/m2 intramuscularly every 6 hours for six doses. Cycles were repeated every 15 days. One patient was not assessable for response. Objective regression was observed in 15 of 37 patients (43%; 95% confidence interval, 26%-60%). One patient (3%) achieved complete response and 14 (40%) achieved partial response. No change was recorded in 14 patients (40%) and progressive disease was noted in six patients (17%). The median time to treatment failure was 7 months and the median survival was 12 months. Toxicity was within acceptable limits but one therapy-related death resulting from severe leukopenia occurred. The dose-limiting toxicity was mucositis. Five episodes of grade 3 or 4 stomatitis were observed and caused dosage modifications of MTX and 5-FU. Biochemical modulation of 5-FU by MTX appears as an attractive modality in patients with advanced gastric cancer. Further investigation both in experimental and clinical fields is needed to clearly define its role and to design the best modulatory strategy.