Forkhead box protein R2 (FOXR2) is associated with human central nervous system neoplasms. However, the expression level of FOXR2 in breast cancer specimens remains largely unknown. To identify whether FOXR2 can serve as a biomarker for the diagnosis and prognosis of breast cancer, real-time PCR and immunohistochemistry (IHC) staining were utilized to detect the expression of FOXR2. The messenger RNA (mRNA) and protein levels of FOXR2 in breast cancer samples were novelty higher compared to non-tumorous breast tissues. IHC results revealed FOXR2 expression was significantly correlated to classifications tumor size (p = 0.007) and Ki-67 (p = 0.019). The patients with high expression of FOXR2 had a significantly poor prognosis compared to those of low expression (p = 0.003), especially in the patients with tumor size ≥2 cm (p = 0.006) and lymph node metastasis status (p = 0.004). Furthermore, multivariate analysis indicated that FOXR2 expression was an independent prognostic factor for breast cancer patients (p = 0.035). This study first identifies that FOXR2 may be an important molecular marker for diagnosis and prognosis of breast cancer.
Keywords: Breast cancer; FOXR2; Immunohistochemistry; Prognostic biomarker.