AFP and hepatocellular carcinoma: Patients were not included in the meta-analysis if they had any of the following: (1) serum bilirubin concentration above 50 mmol/L, prothrombin rate below 45%, serum aspartate aminotransferase above 3N, or serum alpha-fetoprotein concentration above 20 ng/L, (2) evidence of hepatocellular carcinoma, (3) comorbidities reducing life expectancy (e.g., ongoing cancer), or (4) inability to undergo regular surveillance.