High dose methotrexate followed by citrovorum factor reversal in patients with advanced cancer.

High dose methotrexate followed by citrovorum factor reversal has been utilized in twenty-six patients with advanced cancer. Four of 10 patients with head and neck cancer had an objective response. One of 7 patients with metastatic osteosarcoma to the lungs had stabilization with twenty treatments over 23 months. One patient with acute lymphocytic leukemia developed marrow aplasia but did not attain remission. The regimen was well tolerated when meticulous attention was paid to hydration, urine alkalinization, renal function and third space fluid accumulation. Life-threatening or lethal toxicity was encountered when these phenomena were not scrupulously observed.