A role for preirradiation PCV chemotherapy for oligodendroglial brain tumors

Oligodendroglial tumors have been identified as a subgroup of glial neoplas ms with a distinctly better response to chemotherapy and overall survival t han purely astrocytic gliomas. Here we report our experience with adjuvant postirradiation and preirradiation chemotherapy using procarbazine, lomusti ne, and vincristine (PCV) in 27 patients with WHO grade II or III oligodend roglioma or oligoastrocytoma. The efficacy of chemotherapy was assessed acc ording to the Macdonald response criteria (complete response, CR; partial r esponse, PR; stable disease, SD; progressive disease, PD) and progression-f ree survival intervals by computed tomography or magnetic resonance imaging . First, we confirm that PCV salvage therapy for patients progressing after radiotherapy is highly effective (n = 11, 1 CR, 5 PR, 5 SD; median progres sion-free survival has not yet been reached, but is longer than 18 months). Second, 3 patients who received radiotherapy plus PCV as first-line therap y achieved CR and 2 achieved SD, and all 5 are progression-free with a medi an follow-up of 12 months. Third, given these encouraging results, 11 patie nts received postoperative preirradiation PCV chemotherapy and were given r adiotherapy only upon progression. Preirradiation PCV chemotherapy was also effective (2 CR, 3 PR, 6 SD; median progression-free survival has not been yet reached, but is longer than 14 months). Patients with anaplastic oligo astrocytomas were as likely to respond to PCV chemotherapy, as were patient s with anaplastic oligodendroglioma. Three patients who had previously resp onded to PCV were successfully treated with a second course of PCV upon rec urrence. PCV chemotherapy was also effective in patients with leptomeningea l spread of oligodendrogliomas. A randomized prospective trial is required to compare the effectiveness and neurotoxicity of first-line PCV chemothera py followed by radiotherapy to the traditional reverse sequence.