Previous treatment by exemestane (both in adjuvant or metastatic treatment).

1st line of chemotherapy different thaan paclitaxel-bevacizumab.

Treatment by paclitaxel-bevacizumab \> 18 weeks.

HER2 positifs et/ou récepteurs aux oestrogènes négatifs.

Previous thrombosis event within the 6 months before inclusion .

Previous significant surgery within the 28 days before treatment start

Previuous coagulopathy.

1st Line Treatment of Bevacizumab-Taxane vs Bevacizumab-Exemestane in Metastatic Breast Cancer