Long-term survivors in glioblastoma multiforme (GBM): An Irish experience.

Abstract

e12516 Background: GBM is an aggressive malignancy with a poor outcome. Retrospective studies have correlated clinicopathologic and molecular variables with prognosis and constructed nomograms predicting outcome. We identified long-term survivors (LTS) in an Irish neuro-oncology center and investigated associations with patient and tumoral variables. Methods: A prospectively maintained database was reviewed for patients (pts) treated at our institution for GBM between Aug 04 and Dec 09. LTS were defined as pts with overall survival (OS) >2 years. OS was calculated from date of diagnosis to death or last follow-up. All pts had at least 2 yrs follow-up. Clinical and pathological characteristics and outcomes were reviewed. Results: Fourteen (9.7%) of 145 GBM pts were identified as LTS. Median OS was 35.1 months (range: 25.4-69.5) compared with 8.9 (range: 0-69.5) in the overall cohort. Ten LTS were male (71%). Median age at diagnosis was 55 yrs (range: 27-73). Primary sites were: 12 cerebral (86%); 1 spinal (7%) and 1 cerebellopontine angle (7%). Ten LTS presented with neurologic symptoms (71%). ECOG performance status (0-4) was documented in 13 LTS: 0 in 29% and 1 in 64% of pts. In 11 LTS (79%) the tumor was optimally debulked; 3 had biopsy only. One pt had radiologic diagnosis later confirmed on biopsy. Histologic subtypes were: 6 conventional GBM (43%), 3 giant cell (21%) and 5 small cell (36%) variants. Thirteen LTS (93%) received cranial radiation with median dose of 60Gy. One pt was previously treated for astrocytoma preventing further radiation. Concurrent chemoradiation was administered to 10 pts (71%), temozolomide in 9 and BCNU in 1. Twelve pts (86%) had tumor progression at a median of 20.2 mos after diagnosis (range: 4.8-31.2). Four LTS had multiple relapses (range 2-3). Four had >1 line of treatment (range 2-5), 4 had further surgery (29%). Four pts are alive including 2 with no evidence of progression after 1st line therapy. Conclusions: In pts treated at our center almost 10% of GBMs were LTS and were characterised by optimal debulking, a high proportion of giant cell GBMs, baseline ECOG ≤1, multiple relapses and lines of treatments. Molecular analyses of these tumors, e.g. MGMT and IDH1 status, is ongoing and may yield further prognostic information.