The association between aquaporin-1 expression, microvessel density and the clinicopathological features of hepatocellular carcinoma

The present study aimed to evaluate the effects of aquaporin-1 (AQP1) level and intratumoral microvessel density (IMD) on the clinicopathological features of patients with hepatocellular carcinoma (HCC). The AQP1 expression levels, IMD and AQP1/IMD ratios in patients with HCC were measured using a semi-quantitative immunohistochemical technique. The association between these features and clinicopathological variables were evaluated. The prognostic impact of AQP1 and IMD on overall survival (OS), and 5-year disease-free survival (DFS) of HCC patients was investigated retrospectively. P<0.05 was considered to indicate a statistically significant difference. A total of 90 cases of HCC were included in the present study. AQP1 was markedly expressed in the membranes of microvessels and small vessels, but seldom in hepatocellular carcinoma cells. Blood vessels in the tumors were markedly stained by anti-cluster of differentiation 34 antibody. AQP1 expression and IMD was significantly correlated with tumor size, histologic grade, Child-Pugh classification, microvascular invasion and tumor-node-metastasis (TNM) stage (P<0.05). Concurrently, for the 5-year DFS and OS, a larger tumor size, poorly differentiated histological grade, B and C Child-Pugh classification, presence of microvascular invasion, high TNM stage, a high AQP1 expression and a high IMD were significant risk factors for mortality. Multivariate analysis revealed that TNM stage and IMD were independent unfavorable prognostic markers for 5-year DFS (P=0.049 and P=0.025, respectively) and OS (P=0.043 and P=0.042, respectively). These data suggest that high AQP1 expression and IMD are associated with tumor progression and prognosis in HCC. The IMD level may serve as an independent indicator for the 5-year DFS and OS.