Invasive tumor cells and prognosis in a selected population of patients with glioblastoma multiforme

BACKGROUND: After surgical resection, the residual, invasive glioblastoma (GBM) cells give rise to a recurrent tumor, which, in 96% of patients, arises adjacent to the resection margin. METHODS: In this study, the authors prospectively enrolled 25 patients with GBM who underwent gross total resection followed by adjuvant radiochemotherapy (with temozolomide). Tumor removal was achieved with resection margins that included the neighboring, apparently normal tissue (between 1 cm and 2 cm from the tumor border [B area]) and the tumor. RESULTS: Patients who had an absence of tumor cells in the neighboring, apparently normal white matter (B area) had better survival than patients who had the presence of tumor cells in the B area (21 months vs 12 months). This difference was statistically significant in univariate analysis (P = .005) and in multivariate analysis (P = .01). CONCLUSIONS: Aggressive tumor removal may improve survival, but the current results indicated that biologic commitment of 'penumbra' cells appear to be the most relevant factor for tumor recurrence and accounts for the fatal outcome of the disease.