The expression of Aquaporin-1 and Aquaporin-3 in extrahepatic cholangiocarcinoma and their clinicopathological significance

Background: The aim of the study was to evaluate the expression and clinicopathological significance of Aquaporin-1 (AQP1) and Aquaporin-3 (AQP3) in extrahepatic cholangiocarcinoma (EHCC). Methods: Immunostaining of AQP1 and AQP3 was performed by EnVision immunohistochemistry in benign and malignant biliary tract tissues. Results: The expression of AQP1 and AQP3 protein were significantly higher in EHCC tumor tissues (P < 0.05 or P < 0.01). Adenoma and paracancerous tissues with positive AQP1 and/or AQP3 protein expression exhibited atypical hyperplasia. AQP1 expression was positive correlated with AQP3 expression in EHCC (P < 0.01). TNM I + II stage and radical surgery, the positive expression of AQP1 and AQP3 In patients with well-differentiation, no invasion, no lymph metastasis, is lower (P < 0.05 or P < 0.01). Average overall survival time of those with positive expression of AQP1 and AQP3 was significant shorter (P < 0.01). Both AQP1 and AQP3 positive expressions were proved to be an independent prognostic factors in EHCC by cox multivariate analysis. The AUC calculated for AQP1 was 0.769 (95% confidence interval [CI]: 0.618-0.920), and that for AQP3 was 0.758 (95%CI: 0.605-0.911, while that for AQP1 and AQP3 was 0.825 (95%CI: 0.658-0.991). Conclusions: Positive expression of AQP1 and AQP3 is closely related to the pathogenesis, severe clinicopathological char-acteristics, aggressive biological behaviors, and dismal prognoses in EHCC.