Chinese guidelines for HER2 testing in breast cancer (2024 edition): summary of key recommendations

In December 2024, the Chinese expert panel released the updated Chinese Guidelines for human epidermal growth factor receptor 2 (HER2) testing in breast cancer (2024 edition), building on the 2019 version and incorporating recent advancements. These guidelines, referred to as the 2024 guidelines, feature significant format changes, enhance clinical applicability and provide more robust evidence-based recommendations. Identifying patients who may benefit from emerging anti-HER2 antibody-drug conjugates (ADCs) therapies has become increasingly important. The 2024 guidelines provide comprehensive guidance on the interpretation and reporting of relevant HER2 statuses. Recent advances in HER2 testing methods, along with the potential role of artificial intelligence in enhancing testing precision, are introduced. The 2024 guidelines reinforce quality control standards across multiple aspects of the testing process, including optimised specimen handling protocols, refined decalcification procedures, improved unstained slide preservation conditions and enhanced gradient external controls. These comprehensive updates are designed to improve the accuracy and clinical relevance of HER2 testing, ultimately contributing to better patient outcomes in breast cancer management.