Treatment Strategies for Glioblastoma in Older Patients: Age is Just a Number (2612)

Objective: Examine the treatment of newly diagnosed elderly (65 or older) glioblastoma (GBM) patients at a single, high-volume cancer center, with a focus on treatments received, tolerability of treatments, and survival outcomes. Background: Optimal care for elderly patients with GBM remains in question due to their exclusion from and underrepresentation in many clinical trials (including EORTC 22981) as well as their historically poor overall survival. Design/Methods: A retrospective chart review was conducted of newly diagnosed elderly (65 years old or older) GBM patients diagnosed from 2011 through 2017 at MD Anderson Cancer Center. 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 22981. Despite their age, these patients generally tolerated treatment well and had favorable outcomes compared to those reported for patients treated on EORTC 22981. 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. Disclosure: Dr. Mandel has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with BAYER. Dr. Youssef has nothing to disclose. Dr. LUDMIR has nothing to disclose. Dr. Patel has nothing to disclose. Dr. JALALI has nothing to disclose. Dr. Treiber has nothing to disclose. Dr. Wu has nothing to disclose. Dr. McAleer has nothing to disclose. Dr. De Groot has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Celldex (rindopepimit); Deciphera Pharmaceuticals (see above), AbbVie (ABT-414), FivePrime Therapeutics, Inc. (cabiralizumab),Genentech (bevacizumab); Celldex (see above); Foundation Medicine, Inc. (diagnostics, genomic testing platform); Novogen (GDC-008. Dr. De Groot has received royalty, license fees, or contractual rights payments from DSMB: VBL Therapeutics (VB111); Novella (ICT-107). Dr. De Groot holds stock and/or stock options in Ziopharm Oncology, Gilead. Dr. De Groot has received research support from Sanofi-Aventis (XL765); Astrazeneca (AZD 0156); EMD-Serono (M2698, Pimasertib); Eli Lilly (numerous durgs); Novartis (numerous durgs); Deciphera Pharmaceuticals DCC2618, altiratinib), Mundipharma (EDO-S101).