Cerebral hemisphere astrocytoma: Treatment results

Eighty two adult patients with histologically proven cerebral astrocytomas of grades I to IV received postoperative radiotherapy at Westmead Hospital between January 1980 and February 1985. The extent of surgery consisted of biopsy alone in 44%, subtotal tumour resection in 48%, and 'complete' tumour removal in 8%. Seventy one patients completed a course of megavoltage irradiation, the majority having received a tumour dose of at least 60 Gy. Patients who underwent surgical resection (complete or incomplete) had a greater median survival (14 months) than those undergoing biopsy (8 months), but the difference was not statistically significant (p = 0.08). By grade, the difference reached statistical significance only for grade III tumours (p = 0.015). Patients with high grade tumours had a significantly lower survival than those patients with tumour of low grade. Median survival for patients with grades I and II, III and IV tumours was 42.0, 12.0 and 7.0 months, respectively. After adjustment for grade, various dosage levels (< 60, 60 or > 60 Gy) did not significantly affect survival, although there was a trend towards improved median survival with higher doses in grade III tumours. Older patients (> 45 years) had a significantly lower median survival (25 months) than younger patients (8 months) (p < 0.0001). When included in a multivariate analysis, the extent of surgery did not significantly influence survival, but increasing tumour grade and increasing age were significant adverse prognostic factors.