The investigators will perform a cross-sectional study in patients with metastatic breast cancer who have failed treatment after the first line and beyond.
In this study, the investigators will be particularly interested in "long-responder" patients, that is to say, in objective response or with stability for 6 months or more under Halaven®, in order to better characterize these patients. Patients must have been treated by Halaven between September 2011 (the year of obtaining the MA in the 3rd line of treatment) and December 2016, to have a sufficient follow-up for the survival data of the patients.
The investigators will also focus on patients with liver metastases because there is limited data in this population.
