A new scoring system for malignant astrocytomas

Currently there are a few scoring systems for malignant astrocytoma, but they are not widely accepted. The aim of this study was to create a scoring system for supratentorial malignant astrocytoma, which could be used in both developed and developing societies.

This study was performed in 128 patients who had supratentorial malignant astrocytoma (grade III or IV). They were operated, and after the operation patients were irradiated with 50-60 Gy.

The mean age was 55.1 years. The mean Karnofsky performance status (KPS) was 51. The tumour removal >90% was achieved in 57.8%. A biopsy was never exclusively performed. The mean survival was 8.2 months and 12-month survival was 25%. Thirteen out of 35 data that we tested had a prognostic value for survival time. By using the most appropriate four parameters (age, KPS, initial seizure and histopathological grade) we created a scoring system - MAS (Malignant Astrocytoma Score). The scores range from 0-16. The area under the ROC (Receiver Operating Characteristic) curve showed that the AUC for the prediction of 6-, 12- and 18-month survival was 0.729, 0.755, and 0.927. We compared MAS with two of the most commonly used scoring systems. The AUC for the same prediction, using the MRC (Medical Research Council) was 0.673, 0.637, and 0.888. For the RTOG (Radiation Therapy Oncology Group) score the AUC was 0.672, 0.700, and 0.854.

We are of the opinion that MAS represents a useful scoring system to determine the severity of the illness and make a prognosis for both individuals and groups of patients with malignant supratentorial astrocytoma. MAS is more accurate than predictions made by other systems currently in use; it includes prognostic factors that are widely accepted; it can be done at the patient's bedside and in clinics in developing societies.