Response of recurrent medulloblastoma to low-dose oral etoposide

Purpose: The outcome for patients with recurrent medulloblastoma has historically been poor, with most patients dying of disseminated disease. Here, we report on seven patients with recurrent medulloblastoma, most heavily pretreated with a variety of chemotherapeutic agents, including parenteral etoposide (VP-16), who showed responses to the administration of repeated courses of low-dose oral VP-16. Patients and Methods: Seven patients age 4 to 16 years were treated with VP-16 after neuroradiographic and clinical evidence of tumor progression. Six had received prior irradiation. All seven had been pretreated with a variety of chemotherapeutic agents and schedules, including parenteral VP-16. VP-16 was administered orally as repeated 21-day courses at 50 mg/m²/d with a 7-day interval between courses. Evaluation consisted of neuroradiographic and clinical examination after completion of every two courses of therapy. Complete blood cell counts were performed weekly. Results: The major toxicity of oral VP-16 was hematologic, with two patients requiring platelet transfusions due to thrombocytopenia and two requiring RBC transfusions. All seven patients developed treatment- related neutropenia. Two patients were supported with granulocyte colony- stimulating factor (G-CSF) between courses. One patient developed infectious epididymitis after course 2 and required intravenous antibiotics; this illness was complicated by Clostridium difficile colitis. There was one episode of fever associated with neutropenia. There were no treatment- related deaths. Of seven patients assessed, six have demonstrated partial responses (PRs) and the remaining patient had stable disease (SD). Conclusion: This report demonstrates the activity of oral VP-16 in the treatment of a small cohort of pretreated patients with recurrent medulloblastoma. This form of administration of oral VP-16 was well tolerated and produced modest toxicity.