The treatment of anaplastic oligodendrogliomas and mixed gliomas.

We evaluated the treatment outcome of 17 patients with anaplastic oligodendroglioma and 17 patients with anaplastic mixed oligodendroglioma-astrocytoma. In the anaplastic oligodendroglioma group, eight patients were treated at the time of the initial admission with radiotherapy and adjuvant chemotherapy, and nine patients were treated at the time of recurrence with salvage chemotherapy. Three patients for whom adjuvant chemotherapy was not successful were also treated with chemotherapy at the time of recurrence. In the initial group, one patient had complete response, three had partial responses, and 4 had stable disease (response and stable disease, 100%), but all except one progressed within 10 months. Of the 12 patients who received chemotherapy during recurrence, there was 1 complete response, 2 partial responses, and 6 stable disease (response and stable disease, 75%), with long response duration and long survival (15-132+ mo). In the anaplastic mixed oligodendroglioma-astrocytoma group, 12 patients were treated at the time of the initial admission and 6 patients treated at the time of recurrence. The initial treatment resulted in two complete responses, three partial responses, and seven stable disease (response and stable disease, 100%), with most responses lasting longer than 12 months. The treatment of the patients with recurrent disease resulted in one partial response and five stable disease (response and stable disease, 100%), with a median time to progression of 6 months. These results suggest that aggressive treatment is beneficial for recurrent anaplastic oligodendrogliomas and mixed gliomas as well as initial mixed gliomas but may offer only minimal advantage over conventional radiotherapy for the initial treatment of anaplastic oligodendrogliomas.