Trastuzumab-rezetecan

This study is a multicenter, observational, real-world investigation. The research plans to enroll 300 HER2-positive and HER2-low breast cancer patients who meet the inclusion criteria. All patients included in the analysis are currently receiving or are scheduled to receive a treatment regimen containing Trastuzumab-rezetecan. There are no restrictions on the treatment regimen, which is entirely based on the clinician's choice. The study aims to evaluate the efficacy and safety of the treatment regimen containing Trastuzumab-rezetecan. After completing screening examinations and assessments, eligible patients will enter the study treatment phase. They will receive the treatment regimen containing Trastuzumab-rezetecan and undergo follow-up visits according to the protocol. During the study treatment period, patients will undergo imaging and safety assessments as per clinical routine, with the investigator's assessment serving as the final result. Upon treatment completion or study withdrawal, corresponding safety examinations and imaging assessment data will be collected. For neoadjuvant patients, pathological complete response (pCR) will be assessed post-surgery by pathologists at the participating centers.