High Farnesoid X Receptor (FXR) expression is a strong and independent prognosticator in invasive breast carcinoma

Farnesoid X Receptor (FXR), a nuclear receptor superfamily member, is related with bile acids, glucose and lipids metabolism and recently with cancer. In the present study the clinical significance of FXR expression in invasive breast carcinoma was evaluated. FXR protein expression was assessed immunohistochemically on paraffin-embedded breast cancer tissues obtained from 115 breast cancer patients and was statistically analyzed with clinicopathological parameters, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) expression, as well as with tumor cells' proliferative capacity and overall and disease-free patients' survival. FXR positivity was noted in 91 (79.1%) and high FXR expression in 51 (44.3%) out of 115 invasive breast carcinoma cases. High FXR expression was significantly associated with smaller tumor size (p=0.0318) and increased tumor cells' proliferative rate (p=0.0375). Invasive breast carcinoma patients presenting high FXR expression showed significantly longer overall and disease-free survival times compared to those with low FXR expression (log-rank test, p=0.0052 and p=0.0058). In multivariate analysis, FXR expression was identified as independent prognostic factor of overall and disease-free patients' survival (Cox-regression analysis, p=0.0023 and p=0.0049, respectively). The present data support evidence that FXR may be implicated at the earlier stage of breast malignant disease progression, being a strong and independent prognosticator of favorable overall and disease-free survival in invasive breast carcinoma.