Targeted therapy in triple-negative metastatic breast cancer: a systematic review and meta-analysis

OBJECTIVE: To perform a systematic review and meta-analysis of randomized controlled trials that compared the efficacy of targeted therapy to conventional chemotherapy (CT) in patients with metastatic triple-negative breast cancer (TNBC). METHODS: Several databases were searched, including Medline, Embase, LILACS, and CENTRAL. The primary end point was progression-free survival (PFS). We performed a meta-analysis of the published data. The results are expressed as hazard ratio (HR) or risk ratio, with their corresponding 95% confidence intervals (95% CIs). RESULTS: The final analysis included twelve trials comprising 2,054 patients with TNBC, which compared conventional CT alone against CT combined with targeted therapy (bevacizumab [Bev], sorafenib [Sor], cetuximab, lapatinib, and iniparib). PFS was superior in previously untreated patients with TNBC who received Bev plus CT compared to CT alone (fixed effect, HR 0.62, 95% CI 0.51-0.75; P<0.00001). Also, PFS was higher in one study that tested Bev plus CT combination in previously treated patients (HR 0.49, 95% CI 0.33-0.74; P=0.0006). Sor plus CT was also tested as first-line and second-line treatments. The pooled data of PFS favored the combination CT plus Sor (fixed effect, HR 0.69, 95% CI 0.49-0.98; P=0.04). Comparisons of iniparib plus CT also had a better PFS than CT alone (fixed effect, HR 0.75, 95% CI 0.62-0.90; P=0.002). CONCLUSION: Targeted therapy, when associated with conventional CT, demonstrated gains in the PFS of patients with TNBC.