Sequential methotrexate and 5-FU in the treatment of colorectal cancer.

Administration of methotrexate (MTX), 5-FU, and leucovorin rescue in 29 patients with metastatic colorectal cancer produced an objective response rate of 41.7%, with two complete remissions. Two patients developed fatal toxic effects and three others had severe toxic effects. This trial, however, supports the evidence for the synergistic effect of this drug combination.