Glioblastoma multiforme (GBM) accounts for up to 60% of
all malignant primary brain tumours in adults, occurring in 2–3 cases
per 100 000 in Europe and North America. In 2005, a Phase III clinical trial
demonstrated a significant improvement in survival over 2, and subsequently
5, years with the addition of concurrent and adjuvant temozolomide (TMZ)
to radical radiotherapy (RT). The aim of this study was to investigate
if the demonstrated improved survival in the literature translated to clinical
This was a retrospective study including all patients with histologically
proven GBM diagnosed from 1999 to 2008 and treated with adjuvant RT at our
institution. A total of 273 patients were identified. Statistical analysis
was carried out using SPSS® v.18 (SPSS, Chicago, IL).
The median survival for the whole group (n=273) over the 10-year period was 7.6 months (95% confidence
interval 6.7–8.4 months). Overall, the cumulative probability of
survival at 1 and 2 years was 31.5% and 9.4%, respectively.
In total, 146 patients received radical RT. 103 patients were treated with
radical RT and TMZ and 43 patients received radical RT alone. The median survival
for patients receiving radical RT with TMZ was 13.4 months (95%
CI 10.9–15.8 months) vs 8.8 months for radical
RT alone (95% CI 6.9–10.7 months, p=0.006). 2-year survival figures were 21.2% vs
4.7%, respectively. On multivariate analysis, independent predictors
of survival included Karnofsky Performance Status, RT dose, TMZ and extent
of surgery. The strongest predictors of poorer outcome based on the hazard
ratio were palliative RT, followed by not receiving TMZ chemotherapy, then
KPS <90 and a biopsy only surgical approach.
This paper demonstrates improved survival outcomes consistent with those
published in the literature for the addition of concurrent and adjuvant TMZ
to radical RT for the treatment of GBM. Although 63% of patients seen
in the clinic were suitable for a combined modality approach, the prognosis
for the lower Radiation Therapy Oncology Group classes still remains poor.