A Real-world Clinical Study of T-DXd for the Treatment of Chinese Patients With HER2 Overexpressing and HER2 Underexpressing Advanced Breast Cancer

The treatment plan will be recommended to the subject by the treating physician in accordance with current clinical practice guidelines and clinical practice, and the patient's decision to receive T-DXd (DS8201) should precede enrollment in this study. The strategy for administering a particular treatment to a subject is not determined a priori by the trial protocol, but should be in accordance with current clinical practice. Because of the non-interventional nature of this study, this study does not alter or interfere with the patient's actual current medical practice.