This will be a multi-center, multi-country, observational, non-interventional, hybrid study among HR+/HER2- stage II or III eBC patients treated with ribociclib + ET or abemaciclib + ET, as per local label in routine clinical care settings.
The study will include a retrospective and a prospective part. The hybrid design will combine retrospective data extraction from patients' EHRs and prospective data collection from validated PRO questionnaires, bespoke questions, and qualitative interviews, to provide comprehensive data on the patient population.
The exploratory objectives will assess HR+/HER2- stage II and III eBC patients treated with abemaciclib + ET. No formal comparison between the cohorts will be made
