Clinical significance of the B7-H4 as a novel prognostic marker in breast cancer.

Increasing evidence has suggested that B7-H4 plays an important role in cancer development not only in immune field. However, the correlation between B7-H4 protein expression and clinical outcome in primary breast cancer has not been investigated. We examined the expression of B7-H4 by Immunohistochemistry in 147 cases of invasive breast carcinomas. Correlation of B7-H4 protein levels with pathological tumor stages and overall survival rates of breast cancer patients were also analyzed. Uni-and multivariate analyses methods were performed to evaluate the prognostic value of B7-H4 expression levels. We found that different expression levels of B7-H4 on breast cancer cells were significantly correlated with patient's pTNM (pathological staging, T: primary tumor; N: regional lymph node; M: distant metastasis) stage (P<0.001), overall survival (P=0.000), p53 (P=0.041). Furthermore, univariate analyses showed that the overall survival rate of the patients with higher B7-H4 expression was significantly worse than that of the patients with lower B7-H4 expression (P<0.001). Multivariate analyses showed that B7-H4 was a significant independent prognostic indicator (P=0.000). Our results suggest that B7-H4 might be closely associated with breast cancer progression. Its high expression may serve as a potential prognostic biomarker in human breast cancer.