Management of glioblastoma in Victoria, Australia (2006–2008)

Abstract

We describe the management of patients with newly diagnosed glioblastoma multiforme (GBM) in a population-based cohort and compare this to a previously studied cohort. We performed a retrospective cohort study of patients diagnosed with GBM from 2006–2008 in Victoria, Australia. Patients were identified from the population-based Victorian Cancer Registry and their treating doctors surveyed by questionnaire. Outcomes were then compared to a study of GBM patients who were diagnosed between 1998 and 2000 using an identical methodology. We reviewed 351 eligible patients. There were slightly more males (62%) and a minority had multifocal disease (13%). Total macroscopic resection, partial resection or biopsy only was performed in 32%, 37% and 24% of patients, respectively. The majority of patients were referred to a radiation oncologist and medical oncologist postoperatively. A total of 56% of patients were treated with postoperative radiotherapy with concurrent and sequential temozolomide and had a median survival of 14.4 months. This was significantly better than patients treated with postoperative radiotherapy alone in the current or earlier cohorts (2006–2008: median survival 6.2 months, p < 0.0001 versus 1998–2000: 8.9 months, p < 0.0001). This study demonstrates that postoperative chemoradiation has become the standard of care in this Victorian population with an associated improvement in median survival.

Introduction

Glioblastoma multiforme (GBM) represents more than 50% of all primary brain tumours in adults and has a poor prognosis [1], [2]. Where feasible, maximal surgical resection is vital to obtain the best outcomes but it is never curative [1], [3], [4]. Prior to 2005, the standard of care for newly diagnosed GBM was maximal surgical resection followed by radiotherapy. Although chemotherapy was sometimes used in the postoperative period, this was not widespread, as the benefits were generally seen to be modest [5]. In 2005, publication of the pivotal EORTC 26981/NCIC-CE3 Phase 3 study by Stupp et al. documented that the addition of temozolomide concurrently to radiotherapy followed by 6 months of temozolomide significantly improved survival of GBM patients [6].

A limited number of studies have examined community adoption of the EORTC 26981/NCIC-CE3 protocol (often referred to as the Stupp protocol) [7], [8], [9], [10]. These studies have shown rapid adoption of the Stupp protocol as a standard postoperative treatment. Factors significantly associated with reduced use of the Stupp protocol were advanced age [7], [8], [9], unsuitability for partial/gross resection [7], [8], [11], poor performance status [7], [8] and unmarried patients [7]. All reports documented improved survival with the use of this protocol but precise quantification was often limited due to the difficulties of defining a comparator group. For example, a review of the surveillance, epidemiology, and end results program (SEER) examined a large population of GBM patients in the USA in 2006 showing that outcomes were comparable to those reported by Stupp et al. [6] although data from a comparable SEER-defined population prior to 2005 were not available. Others compared outcomes in groups that received chemoradiation but included groups who received ad hoc chemoradiation prior to 2005, presumably in carefully selected patients [8], [9], [10].

We have previously reported a detailed study about the patterns of care and outcomes of patients with GBM treated in Victoria, Australia from 1998–2000, well before the adoption of the Stupp protocol [2], [12], [13]. This current study examined patients treated between 2006 and 2008, using an identical methodology to our previous study. The purpose was to identify patterns of care and outcomes in an Australian population between 2006 and 2008. Further, we aimed to examine outcome differences between two distinct cohorts: pre-Stupp protocol and post-Stupp protocol.