Expression of AQP3 and AQP5 as a prognostic marker in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a common type of breast malignancy with high a propensity for metastasis and locoregional recurrence. The aim of the present study was to investigate the expression of aquaporin (AQP) 3 and AQP5, analyze their association with clinicopathological parameters and explore their clinical significance in tissue samples from patients with TNBC. Immunohistochemistry was performed to detect the expression patterns of AQP3 and AQP5 in 96 patients with TNBC who underwent surgery between 2007 and 2012. AQP3 and AQP5 were expressed primarily in the membrane and cytoplasm of tumor cells within TNBC tissues. AQP3 and AQP5 expression was notably stronger in carcinoma tissue compared with adjacent normal tissue. Overexpression of AQP3 and AQP5 was significantly associated with tumor size, lymph node status and local relapse/distant metastasis. In addition, aberrant overexpression of AQP5 was observed more frequently in TNBC tissues with higher Ki-67 expression than in those with lower Ki-67 expression. In univariate analysis, patients with TNBC with high AQP3 and AQP5 expression demonstrated poorer 5-year disease-free survival and overall survival compared with patients with low AQP3 and AQP5 expression. In multivariate analysis, the combined expression of AQP3 and AQP5 was an independent prognostic marker in patients with TNBC. The results of the present study suggest that the overexpression of AQP3 and AQP5 may serve as a novel therapeutic marker in patients with TNBC.