Breast Cancer: Biochemical Insights and the Therapeutic Potential of Plant-Derived Bioactive Compounds

Abstract

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer-related mortality among women worldwide. This review examines the biochemical mechanisms underlying breast cancer development and progression and evaluates the therapeutic potential of plant-derived bioactive compounds, with emphasis on their molecular targets, anticancer activities, and translational prospects. Breast cancer is a heterogeneous and multifactorial disease driven by genetic and epigenetic alterations that disrupt cellular proliferation, differentiation, survival, and genomic stability. Molecular classification commonly includes hormone receptor-positive and HER2-positive tumours, as well as major subtypes such as luminal A, luminal B, HER2-enriched, and triple-negative breast cancer (TNBC). Breast cancer progression is associated with the hallmarks of cancer, including sustained proliferative signaling, evasion of growth suppression and cell death, replicative immortality, angiogenesis, invasion and metastasis, metabolic reprogramming, and immune evasion. Metabolic alterations support the energetic and biosynthetic demands of tumour cells. Plant-derived bioactive compounds, including polyphenols, flavonoids, isoflavones, catechins, and isothiocyanates, have emerged as promising candidates for breast cancer prevention and management. Compounds such as curcumin, resveratrol, genistein, sulforaphane, quercetin, epigallocatechin gallate (EGCG), and corn silk-derived constituents exhibit anticancer activities through interconnected mechanisms, including cell-cycle arrest, apoptosis induction, modulation of tumour suppressor and oncogenic signaling, and regulation of hormone receptor pathways. These compounds influence pathways involving p53, PTEN, PI3K/AKT/mTOR, MAPK, NF-κB, ER, PR, and HER2. Overall, the evidence supports the potential of plant-derived bioactive compounds as promising candidates for breast cancer prevention and treatment. However, most evidence remains preclinical, highlighting the need for further mechanistic, pharmacokinetic, safety, and well-designed clinical studies.