Effects of zoledronic acid on osteosarcoma progression and metastasis: systematic review and meta-analysis.

2 2 Zoledronic Acid (ZA) has been shown to inhibit Osteosarcoma (OSA) progression in preclinical studies. However, the use of ZA as an intervention for OSA treatment and management remains controversial. A systematic review and meta-analysis of randomized-controlled trials comparing the use of ZA with standard treatment vs. standard treatment alone for OSA patients after resection was conducted. Primary outcomes assessed event-free survival (EFS) and overall survival (OS) rates, while secondary outcomes assessed impact of ZA on metastatic spread, histological response and adverse events occurrence. A literature search was conducted using EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. The Cochrane risk of bias tool (version 2) was used to assess trial quality. RevMan v5.4 was used for the meta-analysis. The between-trial heterogeneity was assessed using the Chitest and the Istatistic and the GRADE methodology was utilized to assess certainty of evidence. Two studies were considered eligible for qualitative synthesis and meta-analysis. ZA had no benefit on EFS (HR, 0.95; 95% CI, 0.48-1.88; p-value 0.88), however, when compared to standard treatment it reduced OS (HR, 1.98; 95% CI, 1.49-2.64; p-value < 0.00001). ZA did not deter lung metastasis (RR, 2.56; 95% CI, 0.35-18.60; p-value 0.35), and neither did it increase good histological response (RR, 0.97; 95% CI, 0.90-1.05; p-value 0.48). ZA treatment was associated with higher risk of adverse events. Based on existing data, the use of ZA as adjuvant therapy is not recommended for the treatment of OSA patients.