Central nervous system gangliogliomas. Part 2: Clinical outcome.

The records of 58 patients with gangliogliomas surgically treated between January 1, 1980, and June 30, 1990, were retrospectively reviewed in order to determine long-term survival, event-free survival, and functional outcome resulting after radical resection and to assess the impact of histological grading on outcome. Tumors were located in the cerebral hemisphere in 19 cases, the spinal cord in 30, and the brain stem in nine. Forty-four patients had gross total resection and 14 had radical subtotal resection. Only six patients underwent postoperative irradiation or chemotherapy and, therefore, the outcome was generally related to surgery alone. Of the 58 gangliogliomas, 40 were classified as histological grade I, 16 were grade II, and two were grade III. The median follow-up period was 56 months. There were no operative deaths, and the operative morbidity rate was 5%, 37%, and 33% for cerebral hemisphere, spinal cord, and brain-stem gangliogliomas, respectively. The 5-year actuarial survival rates for cerebral hemisphere, spinal cord, and brain-stem gangliogliomas were 93%, 84%, and 73%, respectively (p = 0.7). The event-free survival rate at 5 years was 95% for cerebral hemisphere gangliogliomas and 36% for spinal cord gangliogliomas (p < 0.05); for brain-stem gangliogliomas the event-free survival rate at 3 years was 53% (p < 0.05). Neurological function at recent follow-up evaluation was stable or improved in 81% of patients. Multivariate analysis (Cox linear regression) revealed tumor location to be the only variable predictive of outcome, with spinal cord and brain-stem gangliogliomas having a 3.5- and 5-fold increased relative risk of recurrence, respectively, compared to cerebral hemisphere gangliogliomas. Histological grade was not predictive of outcome, although in each location there was a trend for higher-grade tumors to have a shorter time to recurrence. It is concluded that radical surgery leads to long-term survival of patients with gangliogliomas, regardless of location, and adjuvant therapy can probably be reserved for special cases.