A Study to Describe the Breast Cancer Patient Population, Treatment, and Results in Indian Patients Receiving Combinations of the Medicines Called Palbociclib for Advanced Breast Cancer

The purpose of this clinical study is to describe the patient population, breast cancer treatment, and breast cancer treatment results of adult female patients who have received palbociclib combination treatments for advanced or metastatic breast cancer in India. There are two groups of patients this study will describe. The first group of patients will have received palbociclib in combination with aromatase inhibitor (as prescribed by the Physician) for the treatment of postmenopausal women with HR+/HER2- advanced breast cancer as initial endocrine-based therapy for their metastatic disease. The second group of patients will have received palbociclib for the treatment of hormone receptor HR+/HER2- advanced or metastatic breast cancer in combination with fulvestrant in women with disease progression following endocrine therapy.