Surgical aspects for improving the prognosis of malignant astrocytic tumors

This study retrospectively examined the median survival times in 370 patients with malignant astrocytic tumors treated in our institute between 1982 and 2003; follow-up review of these patients continued through the end of April, 2004. The study period was divided into three treatment eras as follows: 1982 to 1988, when patients underwent no preoperative magnetic resonance (MR) imaging evaluation (pre MR era) ; 1989 to 1996, when patients underwent preoperative MR imaging (post MR era) ; and after 1997, when patients underwent preoperative MR imaging with functional brain mapping and intraoperative neuronavigation system monitoring (post MAP era). Patients with glioblastoma (GB) treated after 2000 were separately classified as the 21st century era because of the large number of patients compared with other eras, and changes to radiation treatment protocols. One hundred and eighty-one patients had anaplastic astrocytoma (AA) and 189 had GB. The patients were also divided into younger (under 60 years) and elderly (60 years or over) groups, and total resection and partial resection or biopsy groups. Survival rates were determined using the Kaplan-Meier method. The statistical significance of differences between life table curves was determined using the logrank test. The median survival time of 62 patients with GB in the 21st century era was 23.1 months. The median survival time in the elderly group was significantly shorter than in the younger group in both patients with AA (p=0.0004) and GB (p<0.0001). The median survival time of patients with AA or GB in both younger and elderly groups tended to improve according to treatment advances. The total resection group had significantly longer median survival time than the partial resection or biopsy group, in both patients with AA (p<0.0001) and GB (p=0.0002) and in the younger (AA: p=0.0001, GB: p=0.0040) and elderly (AA: p=0.0230, GB: p=0.0265) groups. Therefore, the outcomes for patients with malignant astrocytic tumors improved according to treatment advances, especially following total resection, despite inhomogeneity in diagnostic criteria, determination of the extent of tumor removal, and treatment protocols.