Patients will attend the sites in accordance with routine clinical practice. It is assumed that visits will be conducted every 3-4 months. Patients will undergo standard procedures and tests according to clinical guidelines and physician's judgement. Available data from routine clinical management of the patients will be collected at patients' visits to the clinical site. Patients enrolled in the study will be followed up until death or study close whichever occurs first. The recruitment period is planned for 24 months, observation period for maximum of 24 months, with total duration of study 4 years. Patients may discontinue from this NIS at any time.
This study is planned as a prospective multicenter NIS. This study is observational in nature and does not impose a therapy protocol, diagnostic/therapeutic interventions or a visit schedule. Patients with HR+/ HER2- advanced or metastatic BC that initiated treatment with ribociclib, alpelisib, mono endocrine therapy or chemotherapy will be included into the study across seven Russian districts.