Dietary factors and special epidemiological situations of liver cancer in Thailand and Africa.

Incidence patterns of primary liver cancer in Swaziland and Uganda have been compared with frequency of contamination of dietary staples by aflatoxins. Geographical regions or tribal groups with elevated cancer incidence were associated with increased frequency of contamination. In further studies, aflatoxin ingestion has been quantitatively measured in populations in Thailand, Kenya, and Mozambique, in subgroups of which the incidence of primary liver cancer varied over a wide range. In each instance, elevated cancer incidence was associated with highest levels of aflatoxin intake. In view of the potency of these compounds as liver carcinogens in many animal species, these data collectively suggest that the aflatoxins are also carcinogenic for man and that regular ingestion of foods heavily contaminated with aflatoxins increases the risk of liver cancer in human populations.