Treatment strategies for glioblastoma in older patients: age is just a number

Background/purpose: Optimal care for elderly patients with glioblastoma (GBM) remains in question due to their exclusion from and underrepresentation in many clinical trials (including EORTC 22,981) as well as their historically poor overall survival. Methods: A 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. One hundred forty-four patients (91.1%) received radiotherapy (RT) and 130 patients (90.3%) received concurrent temozolomide with RT. Sixty-one patients (38.6%) completed concurrent chemoradiation and 6 cycles of adjuvant temozolomide. 23% of patients discontinued temozolomide during concurrent or adjuvant treatment due to side effects or complications of chemotherapy. With a median follow-up time of 35.0 months, median overall survival (OS) time for the full 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 RT course (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 independently associated with improved OS. Conclusions: Our cohort of elderly GBM patients was predominantly treated with standard of care therapy based on EORTC 22,981. Despite their age, these patients generally tolerated treatment well and had favorable outcomes compared to those reported for patients treated on EORTC 22,981. Based on these findings, using advanced age as the basis for treatment de-escalation or as an exclusionary criterion in clinical trials should be discouraged.