The lack of a specific association between arsenic in drinking water and hepatocellular carcinoma

Background/Aims: Liver cancers, particularly angiosarcomas, among patients with arsenic intoxication have been reported for more than half a century. Studies on cancers of urinary system and skin showed the carcinogenic effect of arsenic was cell-type specific. To evaluate whether this is also true for liver cancers, a study was conducted in 243 townships in Taiwan. Methods: Cases of liver cancer were identified through the National Cancer Registry Program. The distribution of major cell-types was compared between an endemic area of arsenic intoxication, including 5 of the 243 townships, and the rest of the townships. Results: A total of 40,832 patients with liver cancer, including 32,034 men and 8798 women, were diagnosed between January 1, 1980 and December 31, 1999 in the study townships. Distributions of the two major cell-types, hepatocellular carcinoma and cholangiocarcinoma, did not appear to be different between the arsenic intoxication endemic area and the other areas. The rest of the cell-types did not have enough cases to provide stable estimates. Conclusions: Convincing evidence in the literature has suggested a specific association between angiosarcoma of liver and arsenic ingestion, but the current study did not find such an association for hepatocellular carcinoma, although it is the major cell-type.