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 methylguanine-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.