Renovascular safety of bevacizumab in breast cancer patients. The prognostic value of hypertension and proteinuria

Summary Introduction The potential prognostic value of hypertension and proteinuria of anti-vascular endothelial growth factor (VEGF) drugs has not been assessed in routine clinical practice so far in breast cancer. The objectives of the MARS study were to assess the prevalence of proteinuria and hypertension at baseline, their incidence under anti-VEGF treatment, and to evaluate a possible link with overall survival. Methods Patients from 8 centres were included between 2009 and 2011 with a follow-up of 1 year. They were naive of any previous anti-VEGF treatment and planned to be started on one. The results of the group of patients with breast cancer receiving bevacizumab are presented. Results Four hundred and two patients with breast cancer and treated with bevacizumab were included. At inclusion, hypertension prevalence was 12.4%, proteinuria 23.9%. The incidence of de novo proteinuria and hypertension during the follow-up was 61.7% and 16.8%, respectively. Among patients with de novo proteinuria, 62.2% afterwards improved/normalized. No thrombotic microangiopathy was reported. Baseline or de novo proteinuria/hypertension were not associated with overall survival in breast cancer patients treated with bevacizumab. Discussion These results on the renovascular safety of bevacizumab in breast cancer patients showed that the prevalence of hypertension and proteinuria was high at baseline and, moreover, patients treated with bevacizumab frequently developed de novo hypertension and/or proteinuria. Finally, neither hypertension, nor proteinuria, neither at baseline, nor de novo, were associated with overall survival in our cohort of "real-life" patients.