patients with breast cancer, at a disseminated stage

patients treated with bevacizumab in combination with weekly paclitaxel as first line chemotherapy and who have progressed

alive patients authorizing the extraction and analysis of their biological samples.

patients with a second neoplasia

deceased patients

patients who have not agreed to participate in the study

her2 positive patients

patients with cns metastases when first treated with bevacizumab in combination with paclitaxel

patients with local-regional recurrence only and

patients with status ned (resected metastases)