High-dose etoposide for refractory malignancies: a phase I study.

Etoposide is active against a number of solid tumors when used in a standard dose. The toxicity at a standard dose level is mild myelosuppression without extramedullary toxicity. Recent studies in man support the dose-response relationship of etoposide. In a group of 22 patients with progressive disseminated malignancies, the dose of etoposide was escalated to define dose-limiting extramedullary toxicity, which was oropharyngeal mucositis at a dose level of 3.5 g/m2. Bone marrow toxicity was completely reversible. No cumulative toxicity was seen. Partial responses were seen in nine patients. In two of three patients with CNS metastases, improvement was seen. Etoposide is a suitable drug for high-dose chemotherapy.