Experimental Carcinoma of Liver in Macaque Monkeys Exposed to Diethylnitrosamine and Hepatitis B Virus

The effects of treatments with diethylnitrosamine (DENA) and hepatitis B virus (HBV) on macaque monkeys were investigated by virus serology and by light and electron microscopy. The experimental groups comprised 43 newborn or juvenile cynomolgus and rhesus monkeys of both sexes. HBV neither had a carcinogenic effect nor increased the oncogenic effect of DENA. However, HBV given to juvenile primates before treatment with DENA resulted in subsequent gross and microscopic alterations consistent with mild hepatitis and postnecrotic cirrhosis; multifocal liver carcinoma apparently developed within these cirrhotic nodules. The pathologic findings in the experimental animals were strikingly similar to those observed in liver cancer patients.