Efficacy of gemcitabine-based chemotherapy in metastatic breast cancer: a meta-analysis of randomized controlled trials

Abstract

Objectives:To compare the effects of gemcitabine-based chemotherapy and gemcitabine-free regimens, a meta-analysis of all relevant randomized controlled trials was performed to investigate the improvement in overall response rate (ORR), time to progression (TTP), and overall survival (OS). A subgroup of gemcitabine-based doublet compared with single agent was also analyzed.Methods:The PubMed and Embase databases were searched for relevant publications reporting randomized controlled trials comparing gemcitabine-based chemotherapy and gemcitabine-free regimens between January 1990 and December 2012. Hazard ratios (HRs) with their 95% confidence intervals (CIs), or data for calculating HRs with 95% CI were derived.Results:Nine trials with a total of 2651 patients were included in this meta-analysis. Compared with gemcitabine-free chemotherapy, gemcitabine-based therapy demonstrated no improvement in terms of ORR (HR 1.09, 95% CI 0.73–1.62; P = 0.67), TTP (HR 0.91, 95% CI 0.72–1.15; P = 0.44) and OS (HR 1.05, 95% CI 0.88–1.25; P = 0.60). In a subgroup including patients who received adjuvant chemotherapy containing anthracyclines or taxanes, sub-analysis assessment revealed that gemcitabine-based doublets were superior to monotherapy in ORR (HR 1.64, 95% CI 1.26–2.12; P = 0.0002) and TTP (HR 0.71, 95% CI 0.62–0.81; P < 0.00001), but no benefit was observed for OS (HR 0.90, 95% CI 0.79–1.03; P = 0.14). The rates of grade 3 and 4 anemia (HR 2.02, 95% CI 1.35–3.02; P = 0.006), neutropenia (HR 2.33, 95% CI 1.37–3.63; P = 0.01), and thrombocytopenia (HR 8.31, 95% CI 5.00–13.82; P < 0.0001) were significantly higher in the gemcitabine-based arm.Conclusions:The present study suggests that gemcitabine-based chemotherapy was as effective as gemcitabine-free chemotherapy in patients with metastatic breast cancer with increased hematological toxicity. Subgroup analysis indicated that adding gemcitabine to monotherapy might be more effective.