摘要AIM:To identify factors associated with the age at onset of hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).METHODS:Five hundred and fifty-six consecutive patients positive for HCV antibody and treatmentna(i)ve HCC diagnosed between 1995 and 2004 were analyzed.Patients were classified into three groups according to age at HCC onset:< 60 years (n = 79),60-79 years (n = 439),or ≥ 80 years (n = 38).Differences among groups in terms of sex,body mass index (BMI),lifestyle characteristics,and liver function were assessed.Factors associated with HCC onset in patients < 60 or ≥ 80 years were analyzed by logistic regression analysis.RESULTS:Significant differences emerged for sex,BMI,degree of smoking and alcohol consumption,mean bilirubin,alanine aminotransferase (ALT),and γ-glutamyl transpeptidase (GGT) levels,prothrombin activity,and platelet counts.The mean BMI values of male patients > 60 years old were lower and mean BMI values of female patients < 60 years old were higher than those of the general Japanese population.BMI > 25 kg/m2 [hazard ratio (HR),1.8,P = 0.045],excessive alcohol consumption (HR,2.5,P = 0.024),male sex (HR,3.6,P = 0.002),and GGT levels > 50 IU/L (HR,2.4,P = 0.014) were independently associated with HCC onset in patients < 60 years.Low ALT level was the only factor associated with HCC onset in patients aged ≥ 80 years.CONCLUSION:Increased BMI is associated with increased risk for early HCC development in HCV-infected patients.Achieving recommended BMI and reducing alcohol intake could help prevent hepatic carcinogenesis.