DNA Methylation in the Regulation and Clinical Application of HER2-Positive Breast Cancer

HER2-positive breast cancer represents an aggressive form of the disease driven by excessive HER2 protein expression or genetic amplification, leading to accelerated tumor growth, heightened metastatic potential, and unfavorable clinical outcomes. Epigenetic dysregulation plays a pivotal role in the pathogenesis of this malignancy, with aberrant DNA methylation patterns serving as one of the key molecular hallmark. These methylation-based biomarkers hold promise for improving diagnostic accuracy, predicting disease outcomes, and assessing treatment efficacy in HER2-positive tumors. Consequently, investigating the relationship between methylation anomalies and disease progression in this subtype is critical for advancing translational research. This review comprehensively examines the molecular signatures and mechanistic underpinnings of DNA methylation dysregulation in HER2-positive breast cancer, its correlation with HER2 overexpression, and its clinical utility. By synthesizing current evidence and prospecting future research directions, this discussion aims to guide future studies and facilitate the development of epigenetically targeted interventions.