Efficacy and Safety of Third-Line Apatinib plus Chemotherapy in Metastatic Triple-Negative Breast Cancer Patients: A Multicenter, Retrospective, Cohort Study

Apatinib is a tyrosine kinase inhibitor (TKI) that targets vascular endothelial growth factor receptor 2 (VEGFR2) as an effective anti-angiogenic agent. The current study intended to explore the treatment efficacy and safety profile of third-line apatinib plus chemotherapy in metastatic triple-negative breast cancer (mTNBC) patients. This multicenter, retrospective, cohort study analyzed 97 mTNBC patients who underwent third-line apatinib plus single-agent chemotherapy (N = 45) or single-agent chemotherapy (N = 52). The objective response rate (44.4% vs. 19.2%, P = 0.007) and disease control rate (77.8% vs. 48.1%, P = 0.003) were higher in the apatinib plus chemotherapy group than in the chemotherapy group. The apatinib plus chemotherapy group had a longer median progression-free survival (PFS) [6.9 (95% confidence interval, CI: 5.2-8.6) vs. 4.3 (95%CI: 3.2-5.4) months, P = 0.008] and overall survival (OS) [11.6 (95% CI: 9.3-13.9) vs. 9.0 (95% CI: 7.3-10.7) months, P = 0.012] than the chemotherapy group. Further adjustment of multivariate Cox's regression analysis verified that apatinib plus chemotherapy (vs. chemotherapy) resulted in a longer PFS (P = 0.003) and OS (P = 0.010). There was no difference in adverse events between the two groups, except that the incidence of hypertension was higher in the apatinib plus chemotherapy group than in the chemotherapy group (P = 0.018); meanwhile, the grade 3-4 adverse events in the apatinib plus chemotherapy group included hypertension (13.3%), neutropenia (8.9%), nausea and vomiting (4.4%), fatigue (4.4%), leukopenia (4.4%), thrombocytopenia (2.2%), and hand-foot syndrome (2.2%). Third-line apatinib plus chemotherapy may achieve a more satisfying survival benefit and no obvious safety concerns in mTNBC patients compared with mono-chemotherapy. However, more large-scale, randomized studies are warranted for further validation.