Screening system for liver cancer in the general population *
This study was undertaken to elucidate the incidence of hepatocellular carcinoma (HCC) in the general population and to establish an effective cost beneficial screening system. The subjects of the study were 3, 709 inhabitants of more than 40 years old out of a population of 32, 537 living in northwestern areas (one city and six towns) of Okayama prefecture. So called 'liver cancer screening' was performed twice in June 1997 and in January 1998. Primary medical examinations included liver function tests (AST I asparate aminotransferase, ALT I alanine aminotransferase, ALP : alkaline phosphatase, GGT : γ -glutamyl transpeptidase, ZTT : zinc sulfate turbidity test) and hepatitis virus markers (HBs-Ag : hepatitis B surface antigen, HCV-Ab : hepatitis C virus antibody). For the HCV-Ab positive cases HCV-RNA examinations were done. Secondary examinations using abdominal ultrasonography (US) were performed on all subjects with positive primary examinations. When US findings suspective of hepatocellular carcinoma (HCC) were obtained, the further more specific examinations were done in hospitals. Out of the 3,709 people (male 1,465, female 2,244 , mean age 62.0±9.9) examined, 35(0.9 %) and 310 (8.4%) were positive for HBs-Ag and HCV-Ab, respectively. Abnormal liver functions were detected in 1,264 (34.1%). Among 310 positive HCV-Ab cases 58.7% (182 cases) were positive for HCV-RNA. Secondary examinations revealed seven cases of HCC, all of whom were positive for HCV-RNA. No cases of HCC were detected in the HCV-RNA negative group among the HCV-Ab positive cases. The incidence of HCC in this general population was 0.19% (7/3, 709). In the HCV-Ab positive cases, it was 2.22% (7/310). In the HCV-RNA positive group, the rate of HCC was 3-78% (7/182). Multivariate analysis disclosed ZTT, ALT, AST and age as important factors related to HCV infection. The most effective way detected persons at high risk for HCC among the general population seems be to follow up cases with abnormal liver functions and positive HCV-RNA. Regarding cost effectiveness, US follow-up for HCV-Ab positive cases with abnormal AST, ALT, and ZTT is most effective. (Accepted on August 20, 1999) Kawasaki Igakkaishi 25(3): 193-202, 1999
