Patterns of initial treatment and survival among older patients with glioblastoma multiforme: Evidence from SEER-Medicare data

Abstract

6625 Background: There is a lack of published data describing routine treatment patterns for glioblastoma multiforme (GBM), particularly in older patients (pts). We report on initial therapies used for treatment of newly diagnosed GBM and related survival among US pts aged 65 years and older. Methods: GBM pts (ICD-O histology codes 9440–9442) were identified in the SEER-Medicare database from 1992 to 2002 and followed through 2004 or until death. Included in the analysis were pts aged 65+ years at diagnosis with no prior cancer diagnosis, enrolled in Medicare Parts A and B, and not enrolled in a Medicare health maintenance organization (HMO). Initial treatment was defined as treatment received within 1 month prior to or 3 months after diagnosis. Use of first-line treatment for GBM was analyzed over all pts, as well as by year of GBM diagnosis; Kaplan-Meier methods were used to assess survival by initial treatment. Results: 3,407 pts met all eligibility criteria. Median age at GBM diagnosis was 75 years; 51.3% of pts were male and 91.9% were white. 88.4% of pts aged 65–74 received active treatment (craniotomy, chemotherapy and/or radiotherapy [RT]), compared to 76.7% of pts aged 75–84, and 50.4% of pts aged 85+. Craniotomy plus RT was the most common initial treatment (40.4% of all pts), followed by craniotomy only (14.9%), RT only (14.7%) and craniotomy plus RT plus chemotherapy (7.8%). Complexity of treatment tended to decrease with age: multiple treatment modalities were used in 62.1% of pts aged 65–74, 42.7% of pts aged 75–84 and 21.3% of pts aged 85+. No notable trend in distribution of initial treatments was observed over the 10-year study period. Pts undergoing craniotomy plus RT plus chemotherapy survived longest (median: 7.6 months; 95% confidence interval: 7.2–8.3 months), followed by those undergoing craniotomy plus RT (6.5; 6.2–7.1). Pts undergoing craniotomy only (2.1 months; 2.0–2.2) and receiving no treatment (2.0; 1.5–2.1) had the shortest survival. Conclusions: The majority of pts aged 65 years or older receive active treatment for newly diagnosed GBM. Among these pts, receipt and complexity of treatment is highest for younger pts and tends to decrease with age. More aggressive initial therapy is associated with longer survival. No significant financial relationships to disclose.