Glut-1 Expression Correlates with Basal-like Breast Cancer.

Background: Glucose transporter 1 (Glut-1) is a facilitative glucose transporter expressed in many cancers including breast cancer. Basal-like breast cancer (BLBC) is a high-risk disease associated with poor prognosis and lacks the benefit of targeted therapy. The aim of this study was to characterize the immunohistochemical (IHC) expression of Glut-1 in patients with BLBC compared with non-BLBC.

Methods: We identified 523 cases of invasive breast carcinoma from our database. The clinicopathologic findings and the biologic markers including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2) status were reviewed. IHC stains for cytokeratin 5/6 (CK5/6), epidermal growth factor receptor (EGFR), p53, and Glut-1 were performed on tissue microarray using standard procedures. BLBC was defined as ER-,PR-, Her2-, and CK5/6+ and/or EGFR+.

Results: Of informative cases, 14.7% were categorized as BLBC versus 85.3% as non-BLBC. Glut-1 was expressed in 42 (76.4%) of 55 BLBCs, whereas only 55 (23.8%) of 231 non-BLBCs showed immunostaining for Glut-1 (P < .001). Overall, Glut-1 expression was significantly associated with high histologic grade, ER negativity, PR negativity, CK5/6 positivity, EGFR expression, and high p53 expression (P < .001). However, there was no correlation between Glut-1 immunostaining and patient's outcome.

Conclusions: Our results show that Glut-1 is significantly associated with BLBC and might be a potential therapeutic target for this aggressive subgroup of breast cancer, and this warrants further investigations.