Effects of treatment on long-term survivors with malignant astrocytomas. We reviewed the records of 160 consecutive patients with glioblastoma and anaplastic astrocytoma to evaluate the long-term consequences of radiation therapy and chemotherapy. We defined long-term survivors as those patients with glioblastoma or anaplastic astrocytoma who lived at least 100% longer than median survival of historical controls, for example, 2 years for patients with glioblastoma and 4 years for patients with anaplastic astrocytoma. There were 9 (5.6%) long-term survivors. Three (30%) became demented and died without evidence of tumor recurrence. One, after survival of 10 years, died of tumor recurrence. Of the remaining survivors, 2 (22%) have significantly impaired short-term memory function and other neurological deficits such as gait apraxia. Three (30%) can function independently. It is likely but cannot be proved that it is radiotherapy and not chemotherapy that is the causal factor of this dismal therapeutic outcome. Our study suggests restraint in the use of radiotherapy for patients with brain tumors that have more favorable prognoses than glioblastomas and anaplastic astrocytomas, such as low-grade astrocytomas and oligodendrogliomas. 