Upregulated expression of AT-rich interactive domain-containing protein 1B predicts poor prognosis in patients with triple-negative breast cancer

The expression of AT-rich interactive domain-containing protein 1B (ARID1B) was investigated in triple-negative breast cancer (TNBC). The association between ARID1B protein expression and the prognosis of patients with TNBC was investigated. The expression of ARID1B was examined in TNBC (n=142) and adjacent normal breast tissues (n=64) using immunohistochemical staining prior to the patients receiving any treatment. Furthermore, the association between ARID1B protein expression and various clinicopathological features was analyzed, including the survival status of patients with TNBC. Of the 142 TNBC tissues, ARID1B was highly expressed in 89 (62.7%) and poorly expressed in 53 (37.3%). ARID1B expression was associated with lymph node metastasis status, histological grade and p53 expression. ARID1B expression was upregulated significantly in the nuclei of TNBC cells compared with those of normal mammary epithelial cells. This upregulation was associated with a decreased progression-free survival rate (P=0.002) and overall survival rate (P=0.003). The results of the present study indicate that significant association exists between the nuclear expression of ARID1B and adverse prognosis in TNBC. Therefore, ARID1B may be a useful prognostic biomarker in TNBC.