Comparative study of hepatocellular carcinoma in Shikoku, Japan: a study of 198 autopsy cases in Tokushima and Ehime Prefectures.

A total of 198 cases with hepatocellular carcinoma (HCC) autopsied in two different areas in Shikoku, Tokushima and Ehime, was examined clinicopathologically. The incidence of HBsAg-positives in overall HCC cases was 49.0%, being higher in Tokushima (52.4%) than in Ehime (43.1%). The difference seemed to be caused by the high incidence in female cases in Tokushima (46.7% in Tokushima vs. 23.1% in Ehime). The mean age of HCC cases with HBsAg (53.9 years) is younger than that of cases without HBsAg (58.8 years). The incidence of HBsAg-positive HCC cases in Shikoku decreased step by step toward older age groups from 63.4% in 41-50, 59.5% in 51-60, 34.6% in 61-70, to 15.8% in over-71 age groups, and has been decreasing gradually with the passage of time from 57.1% in 1960-1971, 50.0% in 1972-1976, to 40.8% in 1977-1981. The incidences of HBsAg-negatives in all autopsy cases increased from 2.0% in 1960-1971 to 3.3% in 1977-1981 (P less than 0.05) although the incidences of HBsAg-positives showed almost the same level. Both in Tokushima and Ehime, the incidences of HCC associated with cirrhosis and HCC with HBsAg were smaller in grade IV cases, and the incidence of HBsAg-positive HCC was high in cases with macronodular type of cirrhosis.