Clustering of liver cancer deaths in Saitama Prefecture, Japan

Cancer statistics in 1965 revealed that people in the eastern part of Saitama had a high risk of developing cancer of the liver. Clusters of liver cancer were also observed in 1975, though less for males than for females. In 1985, traces remained of clusters with higher death rates from liver cancer. A field survey revealed absence of correlation between geographical clustering of liver cancer and HBsAg positivity, geographical HBsAg positivity differences between sexes, and lack of correlation between geographical distribution of HBsAg positivity and death rates from liver diseases (cancer or cirrhosis). There was no geographical relationship of death rates from liver cancer to liver cirrhosis in Saitama. Statistics of the Saitama Cancer Center revealed lower averages than in the rest of Japan for the percentage of HBsAg positivity in HCC inpatients, the percentage of HCC inpatients with liver cirrhosis, and the ratio between the number of patients with HCC and those with cholangio carcinoma. A mail questionnaire revealed that farmers in the eastern part of Saitama had a strong positive association with death from liver cancer. These results suggest that HBV does not play an important role in the clustering of high death rates from liver cancer in Saitama.