The 2025 National Breast Cancer Conference, held in Beijing from April 11 to 13, featured the highly anticipated update to the CSCO Guidelines for the Diagnosis and Treatment of Breast Cancer (CSCO BC Guidelines). The latest edition further refines stratified treatment strategies and emphasizes the importance of both precision medicine and combination therapies—providing more detailed and practical guidance for clinicians. To explore the key updates, Oncology Frontier invited Prof. Chunfang Hao from the Tianjin Cancer  Hospital (Airport Hospital) to elaborate on recent advances in the endocrine management of hormone receptor-positive (HR+) metastatic breast cancer (mBC).

Oncology Frontier: The latest update of the CSCO BC Guidelines was released at this year’s National Breast Cancer Conference. Could you highlight the major revisions in the 2024 edition? From your perspective, what impact will these changes have on clinical practice for breast cancer?

Prof. Chunfang Hao: Over the past year, the breast cancer field has witnessed the publication of numerous pivotal clinical trial results and the approval of several new therapies in China. This has significantly expanded the treatment landscape for HR+ metastatic breast cancer, evolving beyond traditional endocrine therapies to include various targeted therapies. We are now entering an era where antibody-drug conjugates (ADCs) and novel targeted agents play a central role in treating HR+ mBC.

In the 2024 edition of the CSCO BC Guidelines, the treatment pathways for endocrine rescue therapy in HR+ mBC are clearly delineated. A key theme remains the prioritization of combination endocrine therapy, particularly the use of CDK4/6 inhibitors in combination with endocrine agents, which continues to be the cornerstone of treatment strategies.

Incorporating New Drugs, Refining Stratification, and Promoting Precision Medicine in HR+ mBC

In this updated edition, the emphasis on “clear stratified treatment pathways and preferred endocrine combination therapy” remains unchanged. CDK4/6 inhibitors combined with endocrine therapy are still the preferred regimen for HR+ mBC patients who have not previously received CDK4/6 inhibitors.

One of the most significant updates in the new guidelines involves tailored treatment strategies for patients with prior failure of tamoxifen (TAM), nonsteroidal aromatase inhibitors (AIs), or steroidal AIs. Beyond CDK4/6-based combinations, the new recommendations now include additional targeted agents such as PI3K inhibitors—particularly inavolisib.

The INAVO120 trial demonstrated that inavolisib, combined with palbociclib and fulvestrant, offered remarkable clinical benefits. The median progression-free survival (PFS) was significantly extended (15.0 vs. 7.3 months; HR = 0.43; P < 0.0001), reducing the risk of disease progression or death by 57%. Based on these data, China’s National Medical Products Administration (NMPA) officially approved this regimen on March 11, 2025, for adult patients with HR+/HER2− locally advanced or metastatic breast cancer who have developed resistance to endocrine therapy and harbor PIK3CA mutations.

In addition, AKT inhibitors combined with endocrine therapy have already been included as recommended regimens for patients with CDK4/6 inhibitor resistance. In China, we anticipate the approval of capivasertib soon. In the updated guidelines, capivasertib combined with fulvestrant is now a Grade III recommendation for patients with prior failure of CDK4/6 inhibitors or steroidal/nonsteroidal AIs.

While the chapter on endocrine therapy for HR+ mBC does not feature major overhauls, the overarching message is clear: the era of precision endocrine therapy has arrived.

However, clinicians must be aware that—unlike CDK4/6 inhibitors—many of these new targeted agents require biomarker testing before use. Therefore, precision diagnostics must be a prerequisite for clinical application.

Beyond endocrine therapies, treatment options for HR+ mBC now also include ADCs and PARP inhibitors, which will be addressed in other sections of the guidelines. We look forward to exploring those developments together.

Professor Chunfang Hao, MD Master’s Supervisor Director, Department of Breast Oncology, Tianjin Cancer  Hospital (Airport Hospital)

Academic and Professional Affiliations:

• Member, Breast Cancer Expert Committee, Chinese Society of Clinical Oncology (CSCO)
• Member, Breast Cancer Committee, Chinese Anti-Cancer Association (CACA)
• Member, Science Popularization Committee for Cancer Prevention and Control, CACA
• Executive Member, Breast Committee, Chinese Medical Women’s Association
• Deputy Chair, Youth Committee on Breast Cancer, Beijing Anti-Cancer Association
• Executive Member, Committee on Personalized Treatment and MDT for Breast Cancer, Beijing Anti-Cancer Association
• Executive Member, Health Management Committee, Beijing Breast Disease Prevention and Treatment Association
• Member, Tumor Pharmacology Committee, Tianjin Pharmacological Society