*Patients in PALOMA-1 and PALOMA-2 received PALBACE^® + LET; patients in PALOMA-3 had endocrine-resistant mBC and received PALBACE^® + FUL. 
^†Includes LET alone in PALOMA-1, LET + PLA in PALOMA-2 and FUL + PLA in PALOMA-3. 
^‡All-causality AEs occurring in ≥10% of patients aged ≥65 years in the as-treated populations were graded in accordance with the maximum grade per CTCAE, version 3.0 (PALOMA-1) or 4.0 (PALOMA-2 and -3) and classified according to MedDRA, version 19.0. 
^§Clustered PTs defined as follows: anaemia includes the PTs anaemia, haematocrit decreased and haemoglobin decreased; infections includes any reported PTs of the System Organ Class Infections and infestations; leukopenia includes the PTs Leukopenia and White blood cell count decreased; neutropenia includes the PTs Neutropenia and Neutrophil count decreased; thrombocytopenia includes the PTs Platelet count decreased and Thrombocytopenia; stomatitis includes the PTs Aphthous stomatitis, Cheilitis, Glossitis, Glossodynia, Mouth ulceration, Mucosal inflammation, Oral pain, Oropharyngeal discomfort, Oropharyngeal pain and Stomatitis.

AE, adverse event; CTCAE, Common Terminology Criteria for Adverse Events; ET, endocrine therapy; FUL, fulvestrant; LET, letrozole; mBC, metastatic breast cancer; MedDRA, Medical Dictionary for Regulatory Activities; n, number of patients; PALOMA, PALbociclib: Ongoing trials in the Management of breast cAncer;  PLA, placebo; PT, preferred term; TEAE, treatment-emergent adverse event.