Safety and Efficacy of Low-Dose Metronomic Cyclophosphamide Plus Vinorelbine in Patients With Metastatic Breast Cancer Previously Treated With Anthracyclines and Taxanes.

The study investigated the safety and efficacy of a low-dose metronomic chemotherapy regimen combining cyclophosphamide and vinorelbine in 25 patients with metastatic breast cancer (MBC) who had previously been treated with anthracyclines and taxanes. The treatment showed a 44% objective response rate at 6 months and a median time to progression of 22 months. The regimen was well-tolerated, with the most common side effects being grade 2 neutropenia and grade 1/2 hair loss. No severe hematologic toxicities or treatment discontinuations due to adverse events were reported. The findings suggested that this combination therapy was safe and exhibited promising antitumor activity, warranting further clinical evaluation.