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 reresection 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 reresection, 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 reresection 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. Reresection for recurrent GBM was associated with improved OS in those with good performance status and could be considered in carefully selected cases.