PP56. GLIOBLASTOMA OUTCOMES: THE UCLH / NHNN EXPERIENCE 2010–2016
Authors: Dr Michael Kosmin, Dr Francesca Solda’, Dr Elena Wilson, Dr Jeremy Rees, Dr Naomi Fersht
Journal: Neuro-Oncology (2017)

INTRODUCTION: Chemo-radiotherapy (CRT) after maximal debulking surgery is the standard of care for patients with glioblastoma (GBM). This study reviews patient outcomes at our centre. Published data show worse outcomes for patients who present with GBM through A&E. This study further investigates this phenomenon by analysing outcomes for those patients fit enough to be treated with radical CRT. METHODS: Patients with GBM operated on between 1 April 2010 and 5 October 2015 at NHNN, and then treated with CRT at UCLH, were included in the study cohort. Data on patient and tumour characteristics, initial patient presentation, CRT treatment and patient outcomes (progression (PFS) and overall survival (OS)) were collected from the electronic patient records and radiotherapy planning systems. Outcome data were censored on 22 March 2016. Survival analysis was performed using logrank test. RESULTS: 134 patients were included in the analysis (55% male, 45% female). They had a median OS of 16 months, and median PFS of 10 months from start of CRT. 70% patients were alive at 1 year; 41% at 2 years. Improved OS was associated with ECOG performance status (PS=0 vs PS>0; p = 0.00212), type of surgery (biopsy vs partial/complete debulk; p<0.001), and age (<60yrs vs 60yrs; p<0.001). Strong but not statistically significant trends for OS were seen with MGMT status (methylated vs non-methylated; p = 0.053) and sex of patient, with females surviving longer (p = 0.14). 17 patients (13%) with IDH-1 mutation had a significantly improved OS (p=0.0432), with a median OS of 27 months. Patients who presented initially through A&E showed a non-significant trend towards reduced OS (p=0.054). This was not due to a significant difference in PS of this cohort: 41% of A&E presenters were PS 0 vs 47% of those that presented via other routes. There was no effect of tumour size (p=0.065), or time from surgery to CRT (p=0.63). Patients treated with Rapidarc intensity modulated radiotherapy did better than those treated with 3D conformal radiotherapy (p=0.028). Patients who had complete debulking surgery did not do significantly better than those who had partial debulking (p=0.24). Analysis of molecular phenotype showed no effect of Ki67 (p=0.98), EGFR amplification (0.068), or PTEN loss of heterozygosity (p=0.64). CONCLUSION: The standard GBM prognostic criteria showed the expected trends in our patients. The 13% of patients with IDH-1 mutation had significantly extended OS. Patients who initially present through A&E showed a trend towards worse OS, but not one that was statistically significant. The aggressive phenotype of GBM that leads to rapid deterioration and poorer outcomes after A&E presentation (as described elsewhere) may be associated with a reduction in PS that precludes radical treatment. This cohort would have been excluded from this study of patients treated radically with CRT. Our data showed no correlation between GBM volume at diagnosis and OS. There is no early stage disease; once a GBM is large enough to become symptomatic, its outcomes are not predictable based on its size alone.