Significant response to apatinib monotherapy in heavily pretreated advanced HER2-positive breast cancer: a case report and literature review.

Although HER2-targeted therapy has been shown to prolong the survival of patients with HER2-positive breast cancer, most patients eventually progress due to drug resistance. Novel treatment options are urgently needed to overcome resistance to HER2-targeted therapy. The VEGF/VEGFR (Vascular endothelial growth factor and its receptors) pathway is essential in tumor angiogenesis, which may be a promising target in HER2-positive breast cancer providing a rationale for the use of tyrosine kinase inhibitors (TKIs) targeting VEGFR. Here, we present a case of a heavily pretreated advanced breast cancer patient who did not respond to HER2-targeted therapy and developed resistance to multiple lines of HER2-targeted treatment. The patient was treated with apatinib at a dose of 500 mg daily, and obtained partial remission (PR) with a progression-free-stage (PFS) of 6 months. Our case indicates that apatinib might have anti-tumor activity in patients with HER2-positive breast cancer with HER2-targeted resistance. This case is of value which may provide new insights into strategies for HER2-targeted therapy resistance options in the clinic.