Attempted dose intensified cyclophosphamide, etoposide, and granulocyte colony-stimulating factor for treatment of malignant astrocytoma.

Patients with malignant astrocytoma continue to respond poorly to chemotherapy and have a dismal prognosis. Cyclophosphamide (CTX) and etoposide demonstrate activity against malignant astrocytoma at standard dosages, with bone marrow suppression as the limiting toxicity. In order to allow dose intensification, minimize leukopenia, and improve efficacy granulocyte colony-stimulating factor (G-CSF) was used in combination with CTX and etoposide. The protocol consisted of CTX (2 mg/m2/d, days 1, 2), etoposide (200-300 mg/m2/d, days 1-3), and G-CSF (5-10 micrograms/d subcutaneously, days 4-18), every 4 weeks. Nine evaluable patients (7 glioblastoma multiforme, 2 anaplastic astrocytoma) were treated, ranging in age from 26-67 (mean 41). One of 9 patients responded (11%) with a partial response (13+ months), 3 had stable disease (33%; 8, 5, 2.5 months), and 5 had progressive disease (3, 2.5, 2, 1.5, 1 months). The median time to progression for responders was 6.5 months, while overall it was 2.5 months. Overall median survival was only 7.0 months. Toxicity was frequent and severe, typically delaying treatment cycles. The most common complications were severe myeolosuppression (9), sepsis (8), rash (6), urinary infection (5), and anorexia (5). Treatment delays caused by infections and other complications occurred often, abrogating the intended dose intensification. The received dose intensity (DI) for CTX was 400-425 mg/m2/week (relative DI 0.41), while for etoposide it was 75 mg/m2/week (relative DI 0.42). In summary, as used in this protocol, dose intensive chemotherapy with CTX, etoposide, and G-CSF does not improve efficacy over standard regimens and results in excessive toxicity.