[Consensus on clinical diagnosis and treatment of breast cancer with low expression of human epidermal growth factor receptor 2 (2022 edition)].

The treatment of breast cancer with low expression of human epidermal growth factor receptor 2 (HER-2) has become a focused area in recent years. With the proved therapeutic effect of antibody-drug conjugate on breast cancer patients with HER-2 low expression, HER-2-low expression may become a new subtype for targeted therapies of breast cancer. Standardized diagnosis and treatment are the foundation to guarantee efficacy. In order to improve the standardization of clinical diagnosis and treatment of HER-2-low breast cancer, the Consensus Expert Committee has summarized the latest domestic and global clinical data and the key relevant publications in recent years. We have combined them with clinical experience of pathologists and oncologists, had a deep discussion within the committee, and developed the consensus. We believe this consensus could help clinicians improve the understanding about HER-2-low breast cancer, promote the accuracy of decision-making and achieve the ultimate goal of prolonging the overall survival and improving the quality of life of patients.