Long-term remission of hormone receptor-positive/HER2-positive metastatic breast cancer due to combined treatment with everolimus/trastuzumab/exemestane: A case report.

The present case report describes a postmenopausal patient with hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)+ metastatic breast cancer, who experienced progression of disease in bilateral lungs, lymph nodes and the liver under previous endocrine therapy and trastuzumab. Following the failure of two lines of endocrine-based treatment, the patient was administered the combined treatment of everolimus, trastuzumab and exemestane following surgical resection of the liver metastasis. A durable partial remission was achieved, which has continued for >27 months. This prominent clinical outcome in this patient demonstrates that the combined administration of endocrine therapy, trastuzumab and everolimus is clinically effective, and may induce long-term remission in patients with HR+/HER2+ metastatic breast cancer.