Monotherapy for estrogen receptor +ve, locally advanced or metastatic breast cancer in postmenopausal women not previously treated w/ endocrine therapy or w/ disease relapse on or after adjuvant anti-estrogen therapy, or disease progression on anti-estrogen therapy. In combination w/ palbociclib for hormone receptor (HR) +ve, human epidermal growth factor receptor 2 (HER2) -ve locally advanced or metastatic breast cancer in women who have received prior endocrine therapy. Combination treatment w/ palbociclib in pre- or perimenopausal women should be combined w/ LH releasing hormone (LHRH) agonist.