HCP-14GLIOBLASTOMA MULTIFORME AMONG ELDERLY: A SINGLE INSTITUTION EXPERIENCE.

BACKGROUND: Treatment of glioblastoma multiforme (GBM) among patients older than 70 with standard 60Gy radiotherapy (SRT) plus temozolomide (TMZ) is challenging in terms of tolerability. Hypofractionated RT (HRT) alone or combined with TMZ is proposed, but results of these prospective randomized trials with favourable KPS patients are pending. METHODS: We retrospectively reviewed all GBM patients aged over 55 treated in our institution from 2010 to 2014. Demographic and tumor characteristics were extracted. Log-rank test and Cox proportional hazards model were used to estimate Kaplan Meier survival and hazard ratio. We divided our cohort in 4 groups according to treatment: concomitant chemoradiotherapy (CCRT) with SRT; CCRT with HRT; HRT alone; TMZ alone. RESULTS: Among the 171 patients identified, the median overall survival (mOS) in patients <70 years was 14.4mo [95%CI(11.7-16.8)] compared with mOS of patients ≥70 years 11.1mo [95%CI(6.1-16.6)] (p = 0.312). 109 patients were treated with CCRT-SRT compared to 15 with CCRT-HRT, 17 with RT alone, and 7 with TMZ alone. There was no difference in the mOS of patients receiving CCRT-SRT [14.2mo 95%CI(12.2-16.8)] compared with CCRT-HRT [14.6mo 95%CI(4.0-17.9)]. Patients on TMZ monotherapy had a poor mOS [4.4mo 95%CI(1.1-7.5)], as did patients on RT alone [3.9mo 95%CI(2.2-10.2)], probably because of negative selection. After RT, 106(81.5%) patients started adjuvant TMZ and received a median of 3 cycles (0-13); 28 completed ≥6 cycles. MGMT status was known in only 24/130 CCRT patients (16 unmethylated; 8 methylated), and was not significantly associated with longer survival. However, in patients receiving an alkalyting agent, mOS in methylated patients was 10.5mo [95%CI(4.0;16.4)] vs 14.3mo [95%CI(7.0;23.6)] in unmethylated patients (p = 0.399). CONCLUSIONS: Our data suggests that either standard CCRT(60Gy) or HRT could be efficiently used in patients over 70 in a non-selected GBM population. The results of ongoing prospective studies will be needed to confirm the toxicity and overall benefit.