Decreased expression of protocadherin 20 is associated with poor prognosis in hepatocellular carcinoma

Abstract

Recently, protocadherin 20 has been reported as a tumor suppressor gene in hepatocellular carcinoma (HCC); however, the prognostic value of protocadherin 20 in HCC remains unclear. Hence, the purpose of this study was to investigate the clinical and prognostic values of protocadherin 20 in HCC patients. The expression of protocadherin 20 was assessed by quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry. Kaplan-Meier curves were created to calculate the overall survival of the patients, and Cox regression models were used to identify the risk factors associated with prognosis. Of 317 primary HCC patients, decreased expression of protocadherin 20 was observed in 184 (58.0%) patients (P < 0.001). Reduced protocadherin 20 protein expression correlated with portal hypertension, poor tumor differentiation, advanced Okuda stage, and Cancer of the Liver Italian Program score (all P < 0.05). Low protocadherin 20 expression was an independent risk factor for mortality (P = 0.018). Furthermore, in our newly developed simple risk score based on protocadherin 20, patients with total score > 1.11 showed significantly poorer outcome; and the predictive value of the score was better than the Barcelona Clinic Liver Cancer stage, Okuda stage, and Child-Pugh classification (Harrell's concordance index = 0.614). Taken together, these findings suggest that protocadherin 20 may represent a novel prognostic biomarker for HCC patients.