Emerging Trends in Breast Cancer Research: Molecular Mechanisms, Therapeutics, and Clinical Applications

Abstract

Breast cancer remains the most frequently diagnosed malignancy among women worldwide and a leading cause of cancer-related mortality. The past two decades have witnessed profound advances in understanding its molecular underpinnings, heterogeneity, and therapeutic vulnerabilities. The traditional classification of breast cancer into hormone receptor–positive, HER2-positive, and triple-negative subtypes has expanded into a continuum of molecularly defined entities based on genomic, transcriptomic, and proteomic signatures. Recent discoveries have highlighted the significance of DNA damage repair pathways, immune evasion mechanisms, cancer stem cell niches, and tumor microenvironmental influences in driving disease progression and therapeutic resistance. Parallelly, novel therapeutic strategies, including cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, antibody–drug conjugates (ADCs), immune checkpoint inhibitors, PARP inhibitors, and targeted nanomedicine, are transforming clinical outcomes. This review comprehensively explores the molecular mechanisms shaping breast cancer biology, recent advances in therapeutic modalities, and translational applications in clinical practice. Emphasis is placed on bridging preclinical discoveries with patient-centered interventions, evaluating the current limitations of standard therapies, and outlining future perspectives in precision oncology for breast cancer.