An Epidemiological, Prospective Cohort Study to Generate Real-world Evidence in Patients with HR*/HER2- Advanced Breast Cancer Treated in the First-line Setting as per Current Standard of Care with an Endocrine-based Palbociclib Combination Therapy

Prospective non-interventional study (NIS) to examine patient-reported outcomes and real world clinical data in patients with HER 2 positive or HER 2 low unresectable or metastatic breast cancer treated with Trastuzumab Deruxtecan