Safety and efficacy of low-dose metronomic cyclophosphamide plus vinorelbine in patients with metastatic breast cancer previously treated with anthracyclines and taxanes.

e13089Background: Metronomic chemotherapy has recently gained attention as a promising experimental strategy, involving alternative or complementary ways of using old and new anticancer chemotherapeutic agents. This study aimed to determine the toxicity, safety, and efficacy of a combination of low-dose metronomic cyclophosphamide (CPA) and　vinorelbine in patients with metastatic breast cancer (MBC) previously treated with anthracyclines and taxanes. Methods: Eligibility criteria were as follows: human epidermal growth factor receptor 2 -negative MBC previously treated with anthracyclines and taxanes, ECOG PS 0~1, and adequate bone marrow and organ function. Prior hormone therapy for MBC was permitted. In this study, patients received vinorelbine (40 mg/m2) intravenously on days 1 and 8, and CPA (100 mg) orally once daily on days 1~14, every third week. The primary endpoints were the objective response rate (ORR) at 6 months and median time to progression (TTP). Secondary endpoints included safety and tol...