Recurrence Pattern Analysis of Primary Glioblastoma

BACKGROUND: Typical recurrence of glioblastoma occurs locally, usually within 2 cm from the original lesion. With improvement of surgical techniques, more aggressive surgical strategies have become feasible, resulting in a significantly increased rate of complete resection. We investigated whether these improvements are also reflected by tumor recurrence pattern. METHODS: Inclusion criteria were first diagnosis of glioblastoma with standard adjuvant radiochemotherapy and histologically proven tumor recurrence. Patients were divided according to recurrence pattern: local recurrence, distant recurrence, or both recurrence patterns. Data were correlated with extent of resection, molecular tumor configuration, clinical status, and survival data. RESULTS: This single-center retrospective study included 97 patients with glioblastoma treated between 2007 and 2014. Local, distant, and combined tumor recurrence patterns were observed in 77 (79.3%), 10 (10.3%), and 10 patients ( 10.3%). Median progression-free survival of all patients was 8 months; median overall survival was 20 months. Median progression-free survival was 7 months for patients with local recurrence, 13 months for patients with distant recurrence, and 9 months for patients with both recurrence patterns (P = 0.646). Median overall survival in the 3 groups was 21 months, 20 months, and 14 months (P = 0.098). No correlation between methylguaninee deoxyribonucleic acid methyltransferase methylation status and recurrence pattern was observed. CONCLUSIONS: Despite complete resection of contrast-enhancing tumor, most recurrences occurred locally. Patients with distant tumor recurrence demonstrated increased progression-free survival. Therefore, to gain local control, we may need to shift toward a more aggressive supramarginal resection, using extensive intraoperative monitoring to avoid permanent deficits.