Revealing the Angiogenic Signature of FH-Deficient Breast Cancer: Genomic Profiling and Clinical Implications

Background: Fumarate hydratase (FH) deficiency is a rare metabolic alteration in breast cancer that may drive tumor progression through angiogenic remodeling. However, its role in shaping the tumor microenvironment remains poorly defined, limiting our understanding of metabolism-driven angiogenesis and its therapeutic significance. Methods: We analyzed genomic and transcriptomic profiles from thousands of breast cancer samples, including the TCGA cohort, to identify FH mutations and copy number alterations. Differential expression, pathway enrichment, and weighted gene co-expression network analysis (WGCNA) were performed to characterize metabolic and signaling changes. Clinical relevance was examined in a triple-negative breast cancer patient with an FH mutation treated with bevacizumab. Results: FH alterations were enriched in larger, primary tumors and in older patients. FH-deficient tumors displayed metabolic reprogramming, with reduced oxidative phosphorylation and TCA cycle activity, accompanied by upregulation of angiogenesis, VEGF signaling, and epithelial-mesenchymal transition pathways. WGCNA identified 11 hub genes (including CDH5, CLDN5, VWF, and PECAM1) linked to a pro-angiogenic microenvironment. A clinical case illustrated a durable and exceptional response to bevacizumab-based therapy in an FH-mutant patient. Conclusions: FH deficiency promotes an angiogenic tumor microenvironment and may serve as a predictive biomarker for VEGF-targeted therapies. These findings underscore the therapeutic potential of exploiting metabolic vulnerabilities to inform precision oncology.