Glioblastoma patient survival predictors treated by the Hong Kong Hospital Authority: a multicenter retrospective 15-year review

Abstract

Objective: To review predictors for overall survival (OS) among glioblastoma (GBM) patients treated by the Hong Kong Hospital Authority. Method: This was a multicenter retrospective study of adult patients with a histological diagnosis of glioblastoma from the 2006 to 2020. Only patients treated by the Hospital Authority’s seven Neurosurgical units were included. Clinical, tumor molecular and radiological data were collected. Predictors for OS were identified by log-rank testing followed by multivariate analysis using Cox-regression. Result: 1033 patients were identified during this 15-year period. The mean age was 57 + 14 years (range 18 to 91) and the female-to-male ratio was 1:1.6. 8% (84/1033) of patients were lost to follow-up. 93% (956) had primary GBM with 58% (602) having a Karnofsky performance scale score (KPS) of < 70 on presentation. The most common tumor location was the frontal lobe (34%, 351) followed by temporal (27%, 279) and parietal lobes (26%, 269). Of the 693 (67%) tumors that were subject to pMGMT methylation testing, 45% (313/693) were methylated. Of the 425 tumors (41%) that had IDH-1 testing, 13% (54/425) were mutated. 31% (320) of patients underwent gross total resection and 15% (155) only had a biopsy. 51% (524/1033) of patients underwent adjuvant concomitant temozolomide chemo-radiotherapy (CCRT). Median OS (mOS) was 11.1 months (IQR: 15.4 months). The 6-, 12- and 24-month survival rates were 71%, 46% and 20% respectively. Although there was an increase in mOS over the three time-periods: 2006-2010 (11.1 months), 2011-2015 (11.4 months) and 2016-2020 (13.0 months), this was not significant (p-value: 0.23, log-rank test) Independent predictors for OS were: preoperative KPS > 80 (adjusted OR: 0.73; 95% CI: 0.56-0.93), gross total or subtotal resection (aOR: 0.70; 95% CI: 0.51-0.94), CCRT (aOR: 0.43; 95% CI: 0.34-0.55), pMGMT methylated (aOR: 0.64; 95% CI: 0.50-0.55) and IDH-1 mutated tumors (aOR: 0.65; 95% CI: 0.44-0.95). Conclusion: This is one of the largest cohorts of Chinese glioblastoma patients in the literature. Patients with pMGMT unmethylated GBM may benefit from temozolomide CCRT. In the last 15 years, there has been no significant increase in overall survival.