The prognosis of anaplastic astrocytoma with radiologic necrosis mimicking glioblastoma

Anaplastic astrocytoma (AA) sometimes shows a rapid poor course like glioblastoma. In this study, we investigated the prognosis of AA with radiologic necrosis which is the representative radiologic finding of glioblastoma. From 1995 to 2010, we operated on 26 patients who were confirmed to have AA. The male: female ratio was 13:13, and the median age was 47.23 years. The mean follow-up period was 3 years. We analyzed the prognostic significance of radiologic necrosis with age, sex, KPS, tumour location, radiologic findings, extent of removal and radiation therapy oncology group recursive partitioning analysis (RTOG-RPA) classification. The median progression-free survival (PFS) was 0.5 (+/- 0.17) years and the median overall survival (OS) was 1.6 (+/- 0.40) years. In univariate analysis, the clinical variables of younger age (p = 0.030) and RTOG-RPA class III (p = 0.043) correlated with longer PFS, and KPS (p = 0.038), radiologic necrosis (p = 0.013) and the extent of removal (p = 0.041) correlated with OS. The median OS was 1.0 (+/- 0.21) year in AA with radiologic necrosis compared to AA without radiologic necrosis, which showed 2.1 (+/- 0.29) years median OS. On multivariate analysis, there was no statistically significant prognostic factor. However, Cox's regression model revealed that gross total removal was associated with a longer OS (hazard ratio = 0.136; 95% CI, 0.018 to 1.046; p = 0.055) compared to partial removal or biopsy. Gross total resection was associated with good prognosis, and AA with radiologic necrosis had poor prognosis like glioblastoma.