[Biochemical modulation with sequential methotrexate (MTX)-5-fluorouracil (5-FU) treatment]

The results of a cooperative study on sequential MTX-5-FU treatment of gastrointestinal cancer were presented. The treatment consisted of three methods, A, B, C. At zero time, MTX 30 mg/m2 (A), 100 mg/m2 (B) and 300 mg/m2 (C) i.v. infusion were given, and 5-FU 600 mg/m2 (A, B, C) was infused 1-3 hours after MTX in gastric cancer patients and 7 hours afterwards in colorectal cancer patients. Twenty-four hours after MTX, leucovorin rescue of 10 mg/m2 p.o. was given either 0 times or once in A, 6 times in B and 8 times in C every 6 hours. In gastric cancer patients, the response rate was 23.2% of 56 cases in A, 40.5% of 37 cases in B and 0% of 3 cases in C. In colorectal cancer patients, the response rate was 28.6% of 21 cases in A, 20.0% of 15 cases in B and 0% of 3 cases in C. Median survival was 7.4 months (M) in total, 5.5 M in A and 7.6 M in B for gastric cancer, and 8.1 M in total, 10.9 M in A and 7.8 Min B for colorectal cancer. Side effects were mild and tolerable. In summary, in this phase II study on gastric cancer, although the response was limited with A, the relatively high response rate of 40.5% with B was promising. The subsequent phase III study will need to evaluate the biochemical modulation with sequential MTX-5-FU treatment in gastric cancer patients.