[A new sequential chemotherapy of methotrexate with 5-fluorouracil against advanced colo-rectal cancer].

A new sequential chemotherapy consisting of intravenous (IV) administration of methotrexate (MTX) 50 mg/m2 followed by 3 equal IV doses of 5-fluorouracil (5-FU) 500 mg/m2 at 1.4 and 21 hrs. and a leucovorin rescue (15 mg/body/8 hr) from 24 hrs. after MTX for 3 days was applied every two weeks for the patients with advanced colo-rectal cancer. The effectiveness of this MTX/3-dose 5-FU regimen was compared retrospectively with that of the standard sequential regimen consisting of the IV administration of MTX 100 mg/m2 followed by a single IV dose of 5-FU 800 mg/m2 one hr. later and a leucovorin rescue (21 mg/body/6 hr) 24 hrs. later given every week, namely MTX/1-dose 5-FU regimen. Partial response was achieved in 7 (46.7%) of 15 evaluable patients with the MTX/3-dose 5-FU regimen and in 3 (13.6%) of 22 evaluable patients with the MTX/1-dose 5-FU regimen (p < 0.05). The median survival times were 13 and 9 months, respectively. There were no significant difference in the patient characteristics between the two groups, and the toxic effects were much lower in the MTX/3-dose 5-FU than in the MTX/1-dose 5-FU regimen. It is therefore, concluded that the MTX/3-dose 5-FU regimen is superior to the standard MTX/1-dose 5-FU regimen.