[High-dose treatment]

High dose administration of anticancer drugs was discussed putting an emphasis on methotrexate and cytosine arabinoside. High dose methotrexate in combination with leucovorin rescue was effective on various kinds of cancer which had become resistant to conventional doses of anti-cancer drugs. The administration of high-dose methotrexate, however, should be performed with meticulous precautions to prevent serious side effects. Side effects included gastrointestinal mucositis, hepatic dysfunction, nausea and vomiting. Central nervous system manifestations were sometimes observed. High-dose cytosine arabinoside of 3 g/m2 per 12 hours X 12 was given by 2-hours infusion to patients with acute leukemia who had become resistant to conventional combination chemotherapy, or to relapsed patients. This regimen in combination with L-asparaginase or anthracyclines resulted in a fairly high remission rate among those intractable cases. High-dose cytosine arabinoside in combination with anthracyclines has recently been tried on patients with acute leukemia as an initial treatment for remission induction and consolidation. In this case, no intensification treatment was performed to maintain remission. Patients treated with this regimen as an initial medication showed a high remission induction rate and long remission duration. Forty percent of the patients were still alive after 3 years.