Abstract
Human epidermal growth factor receptor 2 (HER2) is a key biomarker and therapeutic target in several malignancies, including breast, gastric, and other solid tumors. Recent advancements in cancer molecular profiling and the Food and Drug Administration's approval of trastuzumab deruxtecan for HER2‐positive pan‐tumor indications have highlighted the broader relevance of HER2 alterations across diverse cancers. However, the lack of standardized guidelines for HER2 testing in a pan‐tumor context creates variability in clinical practice, hindering the optimal implementation of HER2‐targeted therapies beyond traditional indications. To address this gap, a multidisciplinary panel of Chinese experts has developed a consensus providing comprehensive recommendations on diagnostic strategies, testing methodologies, and clinical applications of HER2 overexpression detection. By establishing a unified framework for HER2 overexpression assessment, this consensus aims to enhance the precision of HER2 testing, optimize patient selection for targeted therapies, and improve clinical outcomes across a wide spectrum of HER2 overexpression malignancies.