HER2-Low Breast Cancer: Where Are We?

Area of Science:

• Oncology
• Pathology
• Pharmacology

Background:

• Traditional breast cancer classification includes luminal-like, HER2-positive, and triple-negative subtypes.
• HER2-low breast cancer is a newly identified subtype with low HER2 expression (IHC 1+ or 2+ without amplification).
• This classification has significant implications for treatment strategies.

Purpose of the Study:

• To review current evidence on HER2-low breast cancer.
• To highlight challenges and future directions in the field.
• To discuss the potential benefits of targeted therapies for this patient group.

Main Methods:

• Review of existing scientific literature and clinical trial data.
• Analysis of pathological assessment methods for HER2-low status.
• Evaluation of treatment efficacy for HER2-low breast cancer.

Main Results:

• Trastuzumab deruxtecan demonstrates significant efficacy in HER2-low breast cancer.
• Several other anti-HER2 therapies are under investigation for this subtype.
• HER2-low breast cancer patients may benefit from targeted treatments.

Conclusions:

• The identification of HER2-low breast cancer broadens the scope of patients eligible for targeted therapies.
• Further research is needed to refine pathological assessment and understand prognostic implications.
• Ensuring global access to newly approved drugs is crucial.