Expression of human voltage-gated proton channel 1 in hepatocellular carcinoma and its significance in survival and prognosis

Objective To investigate the expression of human voltage-gated proton channel 1 (HVCN1) in hepatocellular carcinoma (HCC) and its significance in survival and prognosis after radical hepatectomy. Methods Clinical data of 92 patients with HCC undergoing radical hepatectomy in the Cancer Center of Guangzhou Medical University between August 2008 and December 2009 were retrospectively studied. The HCC ard para-carcinoma tissues were chosen and studied. Among the 92 patients, 82 were males and 10 were females with the average age of (51±12) years old. The informed consents of all patients were obtained and the local ethical committee approval had been received. HVCN1 expression in HCC and para-carcinoma tissues was detected by immunohistochemistry. HVCN1 expression in HCC tissues was observed and the correlation between the positive expression of HVCN1 and clinicopathological parameters was analyzed. In addition, the survival and prognosis of HCC patients as well as the influencing factors were also analyzed. The analysis on the correlation between the expression of HVCN1 and clinicopathological parameters was conducted using Chi-square test or Fisher's Exact Test. The survival analysis was conducted using Kaplan-Meier method and Log-rank test. The analysis on influencing factors of survival and prognosis was conducted using Cox Proportional Hazard Regression Model. Results The positive expression of HVCN1 in HCC tissues was 29% (27/92), which was significantly higher than 12% (5/40) of that in para-carcinoma tissues (χ2=2.076, P<0.05). High HVCN1 expression in HCC tissues was correlated with tumor capsule (P<0.05), vascular invasion (χ2=4.937, P<0.05) and early postoperative recurrence (χ2=8.081, P<0.05). The 1-, 3-, 5-year accumulated survival rate was respectively 81.5%, 41.0%, 29.3% for patients with positive HVCN1 expression, and 92.1%, 61.0%, 61.0% for patients with negative HVCN1 expression. The overall survival rate of patients with positive HVCN1 expression was significantly lower than that of patients with negative HVCN1 expression (χ2=8.226, P<0.05). The 1-, 3-, 5-year disease-free survival rate was respectively 51.9%, 13.5%, 13.5% for patients with positive HVCN1 expression and 70.6%, 34.0% and 34.0% for patients with negative HVCN1 expression. The disease-free survival rate of patients with positive HVCN1 expression was significantly lower than that of patients with negative HVCN1 expression (χ2= 5.302, P<0.05). Multivariate Cox regression analysis showed that positive HVCN1 expression and liver cirrhosis were the independent risk factors affecting the survival and prognosis of patients with HCC after radical hepatectomy (RR=2.520,2.408; P<0.05). Conclusions High HVCN1 expression in HCC tissues was correlated with tumor capsule, vascular invasion and early postoperative recurrence, and is the independent risk factor affecting the survival and prognosis of patients with HCC after radical hepatectomy, which can be used as the predictive index for patients with HCC after radical hepatectomy. Key words: HVCN1; Carcinoma, hepatocellular; Hepatectomy; Prognosis