THE ROLE OF EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) IN IDENTIFYING EPIGENETIC BIOMARKERS FOR BREAST CANCER: A NARRATIVE REVIE

Abstract

Breast cancer remains the most common malignancy among women worldwide and a leading cause of cancer-related mortality. Advances in epigenetics, particularly through the Epigenome-Wide Association Study (EWAS) approach, have provided new opportunities to identify epigenetic biomarkers for early detection, risk assessment, and therapeutic monitoring. This narrative review aims to describe the role of EWAS in identifying DNA methylation biomarkers relevant to breast cancer and to highlight current methodological challenges. Literature was retrieved from PubMed, ScienceDirect, and Google Scholar using the keywords “EWAS,” “breast cancer,” “DNA methylation,” and “epigenetic biomarker,” focusing on studies published between 2015 and 2025. Findings indicate that EWAS can reveal methylation patterns associated with cancer risk, prognosis, and potential for noninvasive detection, with alterations detectable even before clinical onset. Several candidate biomarkers identified include methylation changes in genes such as BRCA1, RASSF1A, CDH1, and APC, as well as specific CpG sites associated with hormonal exposure and lifestyle-related risk factors. Despite technological advances in microarray platforms and bioinformatics, many studies still face issues such as cross-sectional design, cellular heterogeneity, and limited replication. These challenges highlight the need for standardized analytical pipelines, larger longitudinal cohorts, and multi-omics integration to improve the reliability and clinical applicability of EWAS findings. Nevertheless, with growing standardization and integration of multi-omics data, EWAS holds significant promise for advancing precision medicine toward more predictive and preventive breast cancer care