Temozolomide's Effectiveness in Treating High Grade Glioma
Background
High grade glioma (HGG) is an aggressive form of brain cancer with a poor prognosis. Treatment typically involves surgery followed by radiotherapy. Temozolomide, an oral chemotherapy drug, has been explored for its potential benefits in both primary and recurrent disease settings.
Objectives
To assess the effectiveness of temozolomide in treating HGG, focusing on overall survival (OS), progression-free survival (PFS), quality of life (QoL), and adverse events.
Methods
A systematic review of RCTs was conducted, comparing temozolomide with no chemotherapy, non-temozolomide chemotherapy, or different dosing schedules of temozolomide in patients with histologically proven HGG.
Results
- Primary Therapy: Three RCTs involving 745 patients showed that temozolomide, when used in both concomitant and adjuvant phases, significantly improved OS (HR 0.60, 95% CI 0.46 to 0.79) and PFS (HR 0.63, 95% CI 0.43 to 0.92) compared to radiotherapy alone. However, it increased the risk of haematological complications, fatigue, and infections.
- Elderly Patients: Two RCTs with 664 patients found that temozolomide alone was comparable to hypofractionated radiotherapy in terms of OS and PFS but was associated with more adverse events.
- Recurrent Disease: In recurrent HGG, temozolomide improved PFS in a subgroup analysis of grade IV GBM tumours but did not improve OS. Adverse events were similar between temozolomide and standard chemotherapy.
Authors' Conclusions
Temozolomide is an effective primary therapy for GBM, improving survival and delaying progression without impacting QoL, albeit with increased early adverse events. In the elderly, temozolomide alone is a suitable alternative to radiotherapy, offering similar survival benefits but with a higher risk of adverse events. In recurrent GBM, temozolomide improves time-to-progression and may benefit QoL without increasing adverse events, though it does not improve overall survival.