[Chinese clinical practice guideline for genetic testing in advanced breast cancer (2025 edition)].

Breast cancer is one of the most common malignancies among women in China. According to GLOBOCAN 2022, more than 350,000 new breast cancer cases were diagnosed in China, ranking second among all newly diagnosed cancers in women. Although breast cancer has entered an era of chronic disease management and overall survival has improved substantially, the prognosis of metastatic breast cancer (MBC) remains unsatisfactory. The genome of MBC is characterized by spatiotemporal heterogeneity and may undergo dynamic evolution. With the continuous identification of actionable alterations, targeted therapies guided by genomic testing have emerged as an important approach to improving patient outcomes. Therefore, the implementation of standardized genomic testing in clinical practice has become an urgent priority. While several international and domestic guidelines have recommended genomic testing for MBC, China still lacks detailed technical specifications and clinical pathways tailored to advanced disease in the local healthcare context. Accordingly, it is imperative to establish a guideline for genomic testing in advanced breast cancer that reflects national realities, ensures strong clinical operability, unifies testing standards, and optimizes workflows, thereby expanding access to precision therapy and improving patient prognosis. Against this background, the Breast Cancer Committee of the Chinese Anti-Cancer Association convened a multidisciplinary working group experts. Following predefined methodological procedures-including clinical question prioritization, systematic evidence retrieval, graded evaluation, and formulation of recommendations-the guideline was developed. It integrates the latest evidence with multidisciplinary expert consensus, providing specific recommendations on key aspects of genomic testing for MBC, including patient eligibility, specimen selection, testing methodologies, and prioritization of target genes. In addition, the guideline systematically summarizes available targeted therapeutic strategies for different genomic alterations, and provides graded recommendations based on both levels of evidence and drug accessibility, thereby ensuring clarity and facilitating clinical implementation. This guideline is closely aligned with the realities of clinical practice and drug accessibility in China, with a strong emphasis on the feasibility of testing and the actionability of results. It establishes a multidisciplinary consensus on standardized pathways for genomic testing in patients with MBC, aiming to bridge precision diagnostics and individualized targeted therapy, and to provide practical guidance for improving the standardization of advanced breast cancer care nationwide.