The Department of Breast Medical Oncology is a specialized clinical department focusing on the diagnosis and treatment of advanced breast cancer. It serves as a research ward of Peking University Cancer Hospital. The department currently has 20 physicians, including 6 chief physicians and 5 deputy chief physicians. There are 23 nurses, comprising 1 chief nurse, 12 supervisor nurses, and 10 senior nurses. Additionally, there are 2 scientific researchers, including 1 associate researcher and 1 assistant researcher. The department has 33 open beds. The department focuses on comprehensive breast cancer treatment, including chemotherapy, endocrine therapy, targeted therapy, and immunotherapy. It emphasizes individualized treatment based on standardized protocols while also prioritizing clinical and translational research. The department is dedicated to precision treatment of breast cancer guided by molecular-level insights, and its diagnostic and therapeutic capabilities are highly renowned nationwide. Over the past five years, the Department of Breast Medical Oncology has led or participated in the completion of multiple projects, including the National Natural Science Foundation of China, sub-projects of the National 973 Program, the Beijing New Century Hundred, Thousand, and Ten Thousand Talents Project, the Capital Medical Development Research Fund, the Specialized Research Fund for the Doctoral Program of Higher Education of the Ministry of Education, the Beijing Health System High-Level Talent Training Program, and the National "12th Five-Year Plan" Major Special Projects. The department has published over 100 articles, including more than 50 SCI-indexed articles. Professor Li Huiping, the department director, is one of the writers of the internal medicine section of the NCCN Breast Cancer Treatment Guidelines (Chinese version) and led the drafting of the Chinese Advanced Breast Cancer Consensus Guidelines (CABC). As a research ward, the department undertakes a large number of international and domestic multicenter drug clinical trials. As a co-leading unit, it spearheaded the completion of the clinical study of fuzuloparib combined with apatinib in advanced breast cancer with germline BRCA mutations (the FABULOUS study). Both drugs received approval for breast cancer indications in December 2024, marking the first PARP inhibitor and angiogenesis inhibitor approved for breast cancer indications in China. As a co-leading unit, the department completed the clinical study of Qilu trastuzumab biosimilar, which was launched in China on July 5, 2024. The department also participated in the clinical study of inavolisib combined with CDK4/6 inhibitors and endocrine therapy (the INAVO120 study), with the second-highest global enrollment. This drug was launched in the United States in October 2024.