Liquid biopsy-based technologies: a promising tool for biomarker identification in her2-low breast cancer patients for improved therapeutic outcomes

Abstract

The molecular classification of breast cancer plays a pivotal role in developing personalized treatment strategies, with the aim of improving therapeutic outcomes. Despite significant advancements, current diagnostic workflows are hindered by several challenges, including pre-analytical variability, interpretive ambiguity, and inconsistencies in threshold definitions, particularly in cases involving human epidermal growth factor receptor 2 (HER2)-low breast cancer. In this context, liquid biopsy technologies have emerged as promising tools for refining breast cancer diagnostics. Techniques such as circulating tumor DNA and circulating tumor cell analysis provide a non-invasive approach to assessing tumor-associated biomarkers. These methodologies are particularly advantageous for analyzing low-abundance materials, such as formalin-fixed paraffin-embedded samples and liquid biopsies, thus enhancing the precision of molecular classification and informing more targeted therapeutic decisions for breast cancer patients. This review aims to explore the potential of liquid biopsy in addressing the limitations of current diagnostic practices, with a specific focus on its application in HER2-low breast cancer. Furthermore, it advocates for a transition toward high-throughput RNA-based screening and quantification, which may address critical unmet clinical needs.