HER-2 expression

Novel agents such as ARX788, patritumab deruxtecan, and Dato-DXd demonstrate promise in overcoming resistance through diversified mechanisms. Real-world data further support a "three-step strategy" involving ADC rechallenge after interim non-ADC therapies, offering a practical, mechanism-informed treatment model. This review provides a framework for precision-guided care in patients with advanced breast cancer and supports ongoing efforts to extend the therapeutic window beyond initial T-DXd benefit.

HER2-low breast cancer was characterized by distinct biological features, including high ER positivity (especially Allred score 8) without PgR association, but did not confer a prognostic advantage over HER2-zero disease. HER2-low status may reflect biological heterogeneity that could be relevant when interpreting treatment response rather than serving as an independent prognostic marker.

Treatment options for both early and advanced-stage TNBC are improving, although it remains the subtype with the poorest outcomes. Ongoing trials are focused on personalizing treatment through predictive biomarkers, response-adaptive strategies, and novel agents, with the goal of maximizing efficacy while minimizing toxicity.

Physician confidence improved (P < 0.001) and the estimated total cost savings, including direct drug costs, vein access devices, and HER2DX costs, amounted to €98 031. HER2DX impacts clinical management in stage I-III HER2-positive BC by supporting treatment adjustments, enhancing physician confidence, maintaining pCR rates, and reducing health care costs.

This is the first study using NLP to evaluate HER2 discordances, which need to be further investigated. Improving AI methods and implementing similar EHR structures among hospitals would increase the success in clinical data extraction.

These findings demonstrated that ebastine effectively disrupts key pathways involved in CSC‑like traits and HER2 activity, even under trastuzumab‑resistant conditions. Its multifaceted inhibitory effects support the repositioning of ebastine as a promising therapeutic strategy for treating refractory HER2‑positive breast cancer.

Together with prior preclinical and clinical evidence, these findings support a context-dependent model in which target downregulation predominates in HER2-low disease, whereas payload resistance or rare binding-site mutations may dominate resistance in HER2-addicted tumors, with important implications for antibody-drug conjugate selection and sequencing. See related article by Chen et al., p. 235.

Both HER2 IHC positive (3+) and FISH positive occur exclusively in pure USC tumors. HER2 gene amplification can be observed in any HER2 IHC levels.

P=N/A, N=30, Active, not recruiting, Lixiaoling

P1, N=29, Active, not recruiting, City of Hope Medical Center | Trial completion date: Jan 2026 --> Dec 2026 | Trial primary completion date: Jan 2026 --> Dec 2026

P3, N=752, Not yet recruiting, Shanghai Chia Tai Tianqing Pharmaceutical Technology Development Co., Ltd.