|Budget Amount *help
¥3,870,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥270,000)
Fiscal Year 2007: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2006: ¥2,700,000 (Direct Cost: ¥2,700,000)
The objectives of this study is to investigate the contribution of risk factors, such as hepatitis B(HBV) or C virus(HCV) infection, severity of liver fibrosis, and lifestyle-related factors in the etiology of hepatocellular carcinoma(HCC). We conducted a nested case-control study using sera stored before HCC diagnosis in the Adult Health Study longitudinal cohort followed up since 1958. We selected 224 HCC cases and 644 controls that were matched to the cases on gender, age, city, time of serum storage, and method of serum storage, and countermatched on radiation dose.
We investigated usefulness of frozen and freeze-dried sera for serological and molecular biological detection of hepatitis B and C viruses. The results indicated that frozen and freeze-dried sera were available for use interchangeably.
Multivariate relative risks(RRs) of HCC(95% confidence intervals) were 45.8(15.2-13.8), 101(38.7-263), 70.7(8.3-601), 4.36 (1.48-13.0), and 4.57(1.85-11.3), for HBV infection alone, HCV infection alone, both HBV and HCV infections, alcohol consumption of 〓 40 g of ethanol/day, and body mass index(BMI) of > 25.0 kg/m^2(obesity) 10 years prior to diagnosis, respectively. HBV and HCV infection and BMI of > 25.0 kg/m^2 remained independent risk factors even after adjusting for severity of liver fibrosis. Among HCV infected individuals, the RR of HCC for a 1kg/m^2 increase in BMI was 1.39(P=0.003), significant multiplicative interaction in HCC risk between HCV infection and increased BMI was observed. Our findings indicated that control of excess weight(especially those with chronic hepatitis C) and antialcoholism may contribute to preventing patients with chronic liver disease from HCC occurrence.