Metabolism-related proteins are differentially expressed according to the molecular subtype of invasive breast cancer defined by surrogate immunohistochemistry

Objective: The purpose of this study was to investigate the expression of metabolism-related proteins such as Glut-1 and carbonic anhydrase IX (CAIX) according to breast cancer molecular subtype. Methods: We generated a tissue microarray of 276 breast cancer patients and performed immunohistochemical staining for known metabolism-related proteins, which were evaluated according to the molecular subtype. Results: The expression of IGF-1, MIF, and HIF-1α was correlated with the HER-2 type (p < 0.05). Glut-1 overexpression and CAIX expression were associated with TNBC type, especially with basal-like type, high histologic grade, estrogen receptor negativity, and progesterone receptor negativity (p < 0.05). The expression of Glut-1 and CAIX was correlated with statistical significance (p < 0.001). Conclusion: We identified different patterns of expression of metabolism-related proteins according to the molecular subtypes of breast cancer defined by surrogate immunohistochemistry. Increased expression of HIF-1α, IGF-1, and MIF was noted in HER-2 type breast cancer and increased expression of Glut-1 and CAIX was noted in TNBC type breast cancer, especially in the basal-like subtype, which exhibited a glycolytic and acid-resistant tumor phenotype.