To systematically elaborate on the epidemiological characteristics, biological basis, diagnostic technology progress, and treatment strategy evolution of HR-positive HER2-low-expressing breast cancer.
Approach:
Diagnosis: Initial screening by immunohistochemistry combined with fluorescence in situ hybridization has formed a standardized process. The integration of digital pathology, next-generation sequencing, and circulating tumor DNA in liquid biopsy technologies has effectively improved diagnostic accuracy and dynamic monitoring capabilities.
Treatment: Endocrine therapy is the cornerstone, and the CDK4/6 inhibitor combination regimen is the standard for advanced first-line treatment. Antibody-drug conjugates, especially deruxtecan, have significantly improved patient prognosis and reshaped the treatment landscape.
Key Findings:
HR-positive HER2-low-expressing breast cancer accounts for nearly 60% of breast cancer cases.
The majority of patients in this subgroup exhibit hormone receptor-positive status (65-83%).
HER2-low expression is defined as IHC 1+ or IHC 2+ with negative FISH.
Interpretation:
HR-positive HER2-low-expressing breast cancer has entered the era of individualized precise treatment guided by molecular typing.
Limitations:
Further exploration of new biomarkers is needed.
Optimization of combination therapy strategies is required.
High-quality clinical research is necessary to improve patient survival outcomes.
Conclusion:
The review highlights the evolution of diagnosis and treatment strategies for HR-positive HER2-low-expressing breast cancer.
