HOUT-18. TREATMENT STRATEGIES FOR GLIOBLASTOMA IN OLDER PATIENTS: AGE IS JUST A NUMBER

Abstract

Abstract BACKGROUND Optimal care for elderly patients with glioblastoma (GBM) remains in question due to their exclusion from and underrepresentation in clinical trials (including EORTC 22981) as well as their historically-poor overall survival. METHODS Retrospective chart review was conducted at a single high-volume cancer center for newly-diagnosed elderly (65 years old or older) GBM patients diagnosed from 2011 through 2017. RESULTS A total of 158 newly-diagnosed GBM patients aged 65 years and older were identified. 144 patients (91.1%) underwent radiation therapy. One-hundred thirty patient (90.3%) received concurrent temozolomide with radiotherapy. A minority of patients (23%) discontinued temozolomide during concurrent or adjuvant treatment due to side effects or complications of chemotherapy. Sixty-one patients (38.6%) completed concurrent chemoradiation and 6 cycles of adjuvant temodar. The median overall survival (OS) time for our cohort was 18.6 months, with estimated OS rates of 74.8%, 35.9%, and 9.5% at 1, 2, and 5 years, respectively. On multivariable analysis, higher KPS (p=0.002, HR 0.46; 95% CI: 0.63–0.82), completing planned course of radiation (p=0.01, HR 0.29; 95% CI: 0.11–0.75), and completing 6 cycles of adjuvant temozolomide (p=0.01, HR 2.62; 95% CI: 1.67–4.12) were associated with improved OS. CONCLUSIONS Our cohort of elderly GBM patients were predominately treated with a standard of care based on EORTC 22981. Despite their age, these patients tolerated treatment well and had a favorable overall survival compared to outcomes reported for patients treated on EORTC 22981. Using age alone as the reason to de-escalate treatment or as an exclusionary criteria in clinical trials should be discouraged.