ERBB2 and breast cancer: The EUropean Real-world experience Of Previously treated advanced/metastatic HER2-positive breast cancer patients Accessing trastuzumab deruxtecan (EUROPA T-DXd) study investigated the effectiveness and safety of T-DXd in a heavily pretreated (third line and beyond) real-world population with HER2-positive metastatic breast cancer at sites in Spain, Italy, and Ireland.