The prognostic impact of zoledronic acid in patients with early breast cancer: systematic assessment

摘要

Objective: The ant of this study was to assess the effectiveness of zoledronic acid in patients with early breast cancer. Materials and Methods: All randomized controlled trials (RCTs) on zoledronic acid for patients with early breast cancer were retrieved from databases including Cochrane Library, MEDLINE, EMBASE, CBMdisc, VIP, and Wanfang databases. RCTs meeting inclusive criteria were included, the data were extracted, quality was evaluated, and cross-checked by two reviewers independently according to Cochrane Handbook for Systematic Reviews of Interventions, and then meta-analyses were conducted using RevMan 5.1 software. A total of eight eligible studies met the search criteria and were evaluated. Results: With respect to follow-up time of five or more years, compared with the control arm, zoledronic acid could significantly improve overall survival rate (odds ratio (OR) = 1.19, 95% confidence interval (CI) 1.02-1.40, p = 0.03); zoledronic acid therapy also had a clear effect on frature events (OR, 0.72, 95% CI, 0.57 to 0.92, p = 0.01); Low level estrogen subgroup analysis indicated that zoledronic acid therapy showed a great beneficial effect on disease recurrence and bone metastasis (OR = 0.66, 95%CI (0.52, 0.84),p = 0.0009, OR = 0.79, 95%CI (0.63, 0.98),p = 0.03, respectively). Conclusion: Compared with the control arm, zoledronic acid significantly improve overall survival. Its clinical benefit is likely to be comprehensive results from reducing the rate of fracture and antitumor effect; zoledronic acid can decrease the recurrence rate and bone metastasis rate at low levels of estrogen; low estrogen is a key factor of the anti-tumor effects. This conclusion should be further proved by conducting more high quality, large-scale RCTs.