Metformin and its derivatives in breast cancer: from glycaemic control to tumor-intrinsic pathways

Metformin and its derivatives exert dual anticancer effects by modulating systemic insulin signaling and targeting tumor-intrinsic pathways. Nevertheless, inconsistencies between preclinical efficacy and clinical outcomes highlight the need for biomarker-guided approaches and deeper investigation into tumour-specific metabolic contects. These complementary mechanisms highlight their potential in precision BC therapy, warranting biomarker-driven studies and optimized therapeutic combinations.