The Efficacy of Bisphosphonate in the Treatment of Giant Cell Tumour of the Bone: A Systematic Review and Meta-Analysis.

Introduction: Anti-osteoclastic mechanism of Bisphosphonate (BP) is crucial to treat Giant Cell Tumour of the Bone (GCTB), however no established guidelines of its use have been published. This systematic review and meta-analysis is the first to summarise recent clinical studies on the subject. Materials and methods: A systematic search was performed based on PRISMA guidelines for clinical trials of BP administration in GCTB. Baseline data including BP regimen, dose and timing was summarised. The primary outcomes assessed were recurrence rate, metastases, survival rate, functional outcome, clinical outcome, radiological outcome, and adverse effect. Results: We identified 8 articles from 2008-2020. Most studies administer 4mg of Zoledronic acid post-operatively, with five studies mentioning pre-operative administration and six studies describing post-operative administration. There was a total of 181 GCTB cases analysed in this study. The BP group presented lower recurrence rate than control group (three studies; Odds Ratio [OR] 0.15; 95% Confidence Interval [CI], 0.05 - 0.43; p<0.05; heterogeneity, I2=0%). As for survival rate, BP group is comparable to control group (two studies; OR 1.67; 95% CI, 0.06 - 48.46; p=0.77; heterogeneity, I2=65%). Conclusion: Bisphosphonate therapy offers satisfactory recurrence rate, functional outcome, clinical outcome, radiological outcome, survival rate and metastases rate in patients with GCTB, with minimal adverse effects. Pre- and post-operative administration of bisphosphonates in combination might be the most beneficial in minimalising the recurrence rate.