Introduction: Postoperative radiotherapy (RT) is utilized routinely in the management of anaplastic WHO Grade III gliomas (AG), including anaplastic astrocytoma (AA) and anaplastic oligodendroglioma (AO). However, the optimal role of RT in elderly AG patients remains controversial. We evaluated the effectiveness of RT in elderly AG patients using a national cancer registry.

Methods: The Surveillance, Epidemiology, and End Results (SEER) database (1990-2008) was used to query patients greater than 70 years of age with AA or AO. Independent predictors of overall survival were determined using a multivariate Cox proportional hazards model.

Results: Among 390 elderly patients with AGs, 333 (85%) had AAs and 57 (15%) had AOs. Approximately two-thirds of AA patients (64%) and AO patients (65%) received RT. Most AO patients (58%) and many AA patients (41%) underwent surgical resection; the remainder had biopsy. The median overall survival for all patients who underwent RT was 6 months (95% confidence interval CI, 5-7 months) versus 2 months (95% CI, 1-6) in patients who did not have RT. Patients who had gross total resection (GTR) plus RT had a median overall survival of 11 months (95% CI, 7-14). Multivariate analysis for all patients showed that undergoing RT was significantly associated with improved survival (hazard ratio HR 0.52, p<.0001). AA tumor type (HR 1.37, p=.03) was associated with worse survival than AO tumor type; female gender (HR 0.59, p<.0001) and being married (HR 0.66, p=.002) significantly improved survival. Patients that underwent GTR had a significant reduction in the hazards of mortality compared to biopsy (HR 0.72, p=.04).

Conclusions: Elderly AG patients undergoing RT had better overall survival compared to patients who did not receive RT. Treatment strategies involving maximal safe resection plus RT should be considered in the optimal management of AGs in elderly patients.

Patient Care: Our research provides new prognostic information helpful in risk-stratifying elderly patients for the optimal management of anaplastic gliomas. It also provides useful results for neurosurgeons and neuro-oncologists to share with their patients during crucial clinical decision-making conversations.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) describe the impact that post-operative radiotherapy has on overall survival of elderly patients with anaplastic gliomas, and 2) Be able to identify the factor(s) that independently predict survival in elderly patients with anaplastic gliomas.

References: 1] Chamberlain MC, Chowdhary SA Glantz MJ. Anaplastic astrocytomas: Biology and treatment. Expert Rev Neurother 2008;8:575-586. [2] Chowdhary S Chamberlain MC. Oligodendroglial tumors. Expert Rev Neurother 2006;6:519-532. [3] Fisher JL, et al. Epidemiology of brain tumors. Neurol Clin 2007;25:867-890, vii. [4] Nomiya T, et al. Prognostic significance of surgery and radiation therapy in cases of anaplastic astrocytoma: Retrospective analysis of 170 cases. J Neurosurg 2007;106:575-581. [5] Paleologos NA Merrell RT. Anaplastic glioma. Curr Treat Options Neurol 2012;14:381-390. [6] Scott J, et al. Effectiveness of radiotherapy for elderly patients with glioblastoma. Int J Radiat Oncol Biol Phys 2011;81:206-210. [7] Stewart LA. Chemotherapy in adult high-grade glioma: A systematic review and meta-analysis of individual patient data from 12 randomised trials. Lancet 2002;359:1011-1018. [8] Stupp R, et al. Effects of radiotherapy with concomitant and adjuvant temozolomide versus radiotherapy alone on survival in glioblastoma in a randomised phase iii study: 5-year analysis of the eortc-ncic trial. Lancet Oncol 2009;10:459-466.