The differences in CXCR4 protein expression are significant for the five molecular subtypes of breast cancer.

The aim was to investigate the expression of the CXCR4 protein in five molecular subtypes of breast cancer. The authors randomly selected the breast cancer paraffin-embedded specimens of the Affiliated Third Hospital of Harbin Medical University between 2007 and 2009. Details are as follows: basal-like subtype-ER (-), PR (-), C-erbB-2 (-), CK5/6 (+), n = 36; normal breast subtype-ER (-), PR (-), C-erbB-2 (-), CK5/6(-), n = 40; luminal A subtype-ER/PR (+), C-erbB-2 (-), n = 38; luminal B subtype-ER/PR (+), C-erbB-2 (+), n = 60; C-erbB-2 (+) subtype-ER (-), PR (-), C-erbB-2 (+), n = 58. Using the immunohistochemistry method, the authors detected the expression of the CXCR4 protein in the five subtypes. The CXCR4 protein expression in the basal-like subtype was the highest, and that in the luminal A subtype was the lowest. In terms of five molecular subtypes of breast cancer, the differences in CXCR4 protein expression were significant (p < .001). In terms of C-erbB-2 expression, tumor stage, and lymph node metastasis of breast cancer, the differences in CXCR4 protein expression were significant (p < .01).