Efficacy Of Vincristine Research Articles

Efficacy of vincristine and cyclophosphamide in the therapy of recurrent medulloblastoma.

We conducted a Phase II study of combination therapy with vincristine and cyclophosphamide in the treatment of patients with recurrent or metastatic medulloblastoma. Fourteen patients were treated with vincristine 2 mg/m2 (2.0-mg maximal dose) by intravenous bolus on Day 1 and cyclophosphamide 1 g/m2 by intravenous infusion on Days 1 and 2, with cycles repeated every 4 weeks. All 4 patients with extraneural disease (biopsy-proven bony metastases) responded (duration of responses 2+, 6+, 8, and 16+ months) and 4 of 8 evaluable patients with neuraxis disease responded (duration of response 2, 2+, 2+, and 21+ months). Toxicity was limited to neutropenia without any episodes of infection. These therapeutic results compare favorably with other reports of therapy for recurrent medulloblastoma and support the inclusion of vincristine and cyclophosphamide in randomized adjuvant therapy trials of patients with medulloblastoma.

A critical review of the use of vincristine (VCR) as a tumour cell synchronizing agent in cancer therapy.

Vincristine (VCR) has been used clinically in so-called 'tumour cell synchronization therapy schedules'. These schedules are based on the assumption that cells, arrested in metaphase by low doses of VCR, subsequently re-enter the proliferative cycle synchronously. However, the evidence that tumour cell synchrony can be achieved under clinical conditions or that 'cell synchronization therapy schedules' yield a better therapeutic response than other efficient combination schemes, is scanty. Further, even in experimental systems, the efficacy of VCR as a cell synchronizing agent is disputed. Indeed, in some systems, cells arrested in metaphase by low doses of VCR, do not re-enter a normal proliferative cycle at all following arrest. In addition, the complex nature of the VCR-tumour interaction and the heterogeneous nature of the tumour cell populations against which it is used augurs badly for the successful application of cell synchronization therapy schedules.