A randomized, open-labelled, phase II trial in the first and second-line metastatic treatment setting, comparing standard endocrine treatment (aromatase inhibitor (AI)) with endocrine treatment plus atorvastatin (1:1). Upon progression in the first line setting, and as part of the translational studies on mechanisms of resistance to endocrine therapy, the patients will receive second line endocrine treatment using fulvestrant. Upon progression to first line treatment, patients that were receiving atorvastatin will stop this treatment.