Efficacy and safety of doublet versus single agent as salvage treatment for metastatic breast cancer pretreated with anthracyclines and taxanes: a systematic review and meta-analysis

Abstract

Aim: To perform a systematic review and meta-analysis of randomized controlled trials to compare the efficacy and safety of doublet versus single agent as salvage treatment for pretreated metastatic breast cancer.

Methods: A comprehensive literature search was performed to identify relevant randomized controlled trials (RCTs). All clinical studies were independently identified by two authors for inclusion. Demographic data, treatment regimens, objective response rate (ORR), and progression-free survival (PFS) and overall survival (OS) were extracted and analyzed using Comprehensive MetaAnalysis software (Version 2.0).

Results: Thirteen RCTs involving 4878 pretreated metastatic breast cancer patients were ultimately identified. The pooled results demonstrated that doublet combination therapy significantly improved ORR (RR 1.13, 95% CI: 1.01–1.27, p < .001) and PFS (hazard ration [HR] 0.83, 95% CI: 0.73–0.96, p = .011), but not OS (HR 0.93, 95% CI: 0.86–1.01, p = .065). Similar results were observed in sub-group analysis according to treatment regimens. Additionally, more incidences of grade 3 or 4 myelosuppression toxicities nausea and fatigue were observed in doublet combination therapy.

Conclusions: In comparison with a single agent alone, doublet combination therapy as salvage treatment for pretreated metastatic breast cancer patients significantly improves ORR and PFS, but not OS. Further studies are recommended to identify patients who will most likely benefit from the appropriate doublet combination therapy.

Keywords:

• Combination therapy
• Meta-analysis
• Metastatic breast cancer
• Salvage treatment

Transparency

Declaration of funding

This study was not funded.

Declaration of financial/other relationships

R.W., T.Z., Y.L., J.H., and Z.Y. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

We are indebted to the authors of the primary studies for, without their contributions, this work would have been impossible.