Oligodendroglial
tumors have been identified as a subgroup of glial
neoplasms with a distinctly better response to
chemotherapy and overall survival than purely
astrocytic gliomas. Here we report our experience with adjuvant postirradiation and preirradiation
chemotherapy using
procarbazine,
lomustine, and
vincristine (PCV) in 27 patients with WHO grade II or III
oligodendroglioma or oligoastrocytoma. The efficacy of
chemotherapy was assessed according to the Macdonald response criteria (complete response, CR; partial response, PR; stable disease, SD; progressive disease, PD) and progression-free 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 progression-free survival has not yet been reached, but is longer than 18 months). Second, 3 patients who received
radiotherapy plus PCV as first-line
therapy achieved CR and 2 achieved SD, and all 5 are progression-free with a median follow-up of 12 months. Third, given these encouraging results, 11 patients received postoperative preirradiation PCV
chemotherapy and were given
radiotherapy 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 oligoastrocytomas were as likely to respond to PCV
chemotherapy, as were patients with
anaplastic oligodendroglioma. Three patients who had previously responded to PCV were successfully treated with a second course of PCV upon recurrence. PCV
chemotherapy was also effective in patients with leptomeningeal spread of
oligodendrogliomas. A randomized prospective trial is required to compare the effectiveness and neurotoxicity of first-line PCV
chemotherapy followed by
radiotherapy to the traditional reverse sequence.