HBXIP expression predicts patient prognosis in breast cancer.

Emerging evidence demonstrated that hepatitis B virus X-interacting protein (HBXIP) has broad roles in cancers. The aim of the study is to investigate the association between HBXIP expression and clinicopathological features of breast cancer patients so as to determine whether HBXIP protein may be correlated with poor prognosis in breast cancer patients. HBXIP protein expression was assessed in a well-characterized series of breast cancer (n=196) with long-term follow-up, using immunohistochemistry method. Correlation between HBXIP expression and clinicopathological factors was analyzed. The effects of several variables on survival were tested by a Cox proportional hazards regression analysis. High HBXIP expression was predominantly observed in breast cancer tissues but not the adjacent normal breast tissues. The expression of HBXIP was high in 125 (63.8%) of the 196 cancer patients and low in 71 (36.2%) of the 196 patients, respectively. High HBXIP expression was positively correlated with TNM stage (P=0.001), lymph node metastasis (P<0.001), and Ki67 expression (P=0.002). The patients with high HBXIP expression had lower 5-year overall survival (OS) and disease-free survival (DFS) rates than those with low HBXIP expression as determined using the Kaplan-Meier method (OS: P=0.006; DFS: P=0.022). In Cox regression analysis, both HBXIP expression (P=0.002 and P=0.009, respectively) and lymph node metastasis (P<0.001 and P=0.008, respectively) were associated with poor OS and DFS. Our study suggested that high HBXIP is associated with the progression of breast cancer. HBXIP could be a valuable prognostic marker as well as a potential molecular therapy target for breast cancer patients.