Breast cancer and metabolic comorbidities: From epidemiology and molecular mechanisms to precision interventions

Figure 1 Type 2 diabetes exacerbates breast cancer progression through hyperglycaemia, impaired glucose tolerance and insulin resistance, driving a shift toward triple-negative subtypes while reducing human epidermal growth factor receptor 2-positive cases. Created in BioRender. Mechanistically, elevated glucose and advanced glycation end products activate fibrinogen C domain containing 1 signalling and induce epigenetic reprogramming - including histone H3 lysine 27 acetylation and matrix metalloproteinase-9 promoter demethylation - that collectively drive metastatic progression. T2DM: Type 2 diabetes mellitus; HER2: Human epidermal growth factor receptor 2; TNBC: Triple-negative breast cancer; MMP-9: Matrix metalloproteinase-9; H3K27ac: Histone H3 lysine 27.