Prognostic factors in supratentorial WHO grade II astrocytoma adults

The records of 33 adult patients with supratentorial World Health Organization grade II astrocytoma (A-II) treated between January 1980 and April 1997 at our hospitals were retrospectively reviewed. All tumours were surgically resected or biopsied and their MIB-1 labelling indices (LIs) were less than 1.5%. The median time to tumour progression after the initial surgery was 60 months, and the 5- and 10-year tumour progression-free rates were 53 and 39%, respectively. The median survival time was 107 months, and the 5- and 10-year survival rates were 66 and 43%, respectively. The major cause of death was tumour recurrence with malignant transformation, comprising 93% of all deaths due to unrestrained tumour growth. In a univariate analysis for survival rate by log-rank test, age ( 60 years), Karnofsky Performance Scale score (90-100%), tumour location (except for the basal ganglia), and extent of surgery (more than biopsy) were revealed to be significant positive prognostic factors. A Cox proportional hazard multivariate regression analysis confirmed that the age was the only independent, significant positive prognostic factor in this series. The survival time after the initial surgery in patients without radiotherapy tended to be prolonged compared with those of the patients with radiotherapy. Of the 26 patients who received radiotherapy, however, the survival time after the initial surgery in the nine patients with intraoperative radiotherapy was significantly prolonged compared with the 17 patients who received sole external beam radiotherapy. Gender, symptoms, histology, p53 LI, enhancement on CT/MRI, cyst, calcification and chemotherapy were not shown to be significant prognostic factors. The optimal management strategy for A-II is expected to be established by clarification of the natural history with cytological and molecular biological analyses of the biological features of this disease.