Metronomic cyclophosphamide and capecitabine combined with bevacizumab in advanced breast cancer

Purpose: Metronomic chemotherapy has shown efficacy in patients with metastatic breast cancer. When used in association with targeted antiangiogenic drugs, it was more active than metronomic therapy alone in preclinical and clinical studies. Patients and Methods: Patients with advanced breast cancer were candidates to receive metronomic oral capecitabine (500 mg thrice daily) and cyclophosphamide (50 mg daily) plus bevacizumab (10 mg/kg every 2 weeks). Results: In 46 assessable patients, we observed one complete response (CR; 2%), 21 partial responses (PR; 46%), 19 patients (41%) with stable disease (SD), and five patients (11%) with progressive disease, for an overall response rate of 48% (95% CI, 33% to 63%). Additional long-term disease stabilization (SD ≥ 24 weeks) occurred in eight patients, for an overall clinical benefit (CR + PR + SD ≥ 24 weeks) of 68% (95% CI, 51% to 81%). Median time to progression was 42 weeks (95% CI, 26 to 72 weeks). Toxicity was generally mild. Grade 3 or 4 nonhematologic adverse effects included hypertension (n = 8), transaminitis (n = 2), and nausea/vomiting (n = 2). Higher baseline circulating endothelial cells (CECs) were correlated with overall response (P = .02), clinical benefit (P = .01), and improved progression-free survival (P = .04). Conclusion: Treatment with metronomic capecitabine and cyclophosphamide in combination with bevacizumab was effective in advanced breast cancer and was minimally toxic. The number of baseline CECs significantly correlated with response and outcome, therefore supporting further studies on this surrogate marker for the selection of patients to be candidates for antiangiogenic treatments.