Prognostic factors influencing survival following re-resection for isocitrate dehydrogenase (IDH) -wildtype glioblastoma multiforme - Data from a national neuro-oncology registry.

The role of surgical resection in recurrent Glioblastoma Multiforme (GBM) remains unclear. We aimed to investigate survival outcomes and associated prognostic factors in patients undergoing surgical re-resection for recurrent IDH-wildtype GBM in a national neuro-oncology center. We evaluated all patients who underwent re-resection for recurrent GBM following adjuvant treatment between 2015 and 2018. 32 patients were eligible for inclusion. 19 (59%) were male,median age at re-resection was 53. Median time from initial surgery to re-resection was 13.5 months. Median overall survival (OS) was 28.6 months from initial surgery and 9.5 months from re-resection. MGMT methylation was significantly associated with improved OS from initial surgery, 40 months versus 19.1 months, (p = 0.004), and from re-resection, 9.47 months versus 6.93 months, (p = 0.028). A late re-resection was associated with improved OS compared to an early re-resection, 44.1 months versus 15.7 months, (p = 0.002). There was a trend for improved outcomes in younger patients, median OS from initial surgery 44.1 months for <53 years compared to 21.7 months for patients ≥53, (p = 0.099). Higher Karnofsky Performance Status (KPS) at re-resection was associated with improved median OS, 9.5 months versus 4.1 months for KPS ≥70 and <70 respectively, (p = 0.013). Furthermore, there was a trend for improved OS with greater extent of re-resection, however this did not reach statistical significance, possibly due to small sample size. Re-resection for recurrent GBM was associated with improved OS in those with good performance status and could be considered in carefully selected cases.