To evaluate the prognostic factors in patients with glioblastoma multiforme (GBM).

GBM is one of the most aggressive brain tumours in adults with a median overall survival (OS) of 9 - 11 months. Defining the prognostic factors in GBM is essential in allowing us to better individualize counseling and therapeutic decisions for our patients. 

We conducted a retrospective analysis on 433 histologically proven GBM patients diagnosed in two Singapore tertiary hospitals between May 2000 and September 2018. We collected patients’ age at diagnosis, gender, ethnicity, presence of seizures at diagnosis, duration of symptoms prior to diagnosis, extent of surgical resection (biopsy versus subtotal resection versus gross total resection), treatment regimen received (radiotherapy versus chemo-radiotherapy versus none), follow-up and OS data. We excluded patients with less than one year of follow-up. OS was defined as the duration from histological diagnosis of GBM to death or last known follow-up. Univariate and multivariate analyses were performed to study the effect of the variables on patients’ OS. 

The median age was 58 years and 60% were males. The median OS of the whole cohort was 10 months. On univariate analysis, age at diagnosis, seizures, extent of resection and chemo-radiation therapy were significantly associated with length of OS. Multivariate Cox regression analysis showed that younger age (HR 1.58 [95% CI 1.229-2.237]; p=0.01), females (HR 0.726 [95% CI 0.555-0.949]; p=0.019), a greater extent of resection (HR 0.518 [95% CI 0.432-0.621]; p<0.001) and chemo-radiation therapy (HR 0.373 [95% CI 0.309-0.450]; p<0.001) remained as independent good prognostic factors after correction for ethnicity, duration of symptoms and presence of seizure.

Age, gender, extent of resection and chemo-radiation therapy are significant prognostic factors in our local patients with GBM. Retrospective testing of molecular markers and the development of a prognostication scoring system are underway.