Data from Northern California Oncology Group protocol 6G61, which was closed in February 1983, were reanalyzed in December 1988. The protocol called for a randomized trial that compared the effects of following 60 Gy radiation/oral hydroxyurea treatment with either carmustine (BCNU) or the combination of procarbazine, lomustine (CCNU), and vincristine (PCV) for two histologic strata: glioblastoma multiforme and other anaplastic gliomas. PCV produced longer survival and time to tumor progression than BCNU for both histologic groups, although the difference was statistically significant only for the anaplastic gliomas. With PCV treatment, time to progression and survival doubled for anaplastic glioma patients in the 50th and 25th percentiles.