Streptozotocin-induced liver tumors in the Syrian hamster.

Streptozotocin was administered in a dose of 50 mg/kg body weight intraperitoneally on three consecutive days to 35 8-week old male Syrian golden hamsters. At sacrifice 16-36 weeks later, macroscopic liver tumors had developed in 27 of 29 surviving animals. The majority of animals had multiple hepatic nodules. Some tumors were already large (greater than 1 cm) 16 weeks after streptozotocin. By histologic criteria, five animals (17%) had hepatocellular carcinoma, 23 (79%) had adenomas with varying degrees of atypia, and one (4%) had a normal liver. No metastases to organs outside the liver were noted. No other primary tumors were observed. Sixteen of 29 animals had ascites. Twenty-five age-matched untreated animals showed no evidence of liver tumors. Although sporadic liver tumors due to streptozotocin have been reported in rats and mice, the high incidence of tumors and short latency period to tumor induction seem to be unique to the Syrian hamster. The development of liver carcinoma without the necessity for long-term administration of the carcinogen and without adjunctive procedures such as partial hepatectomy represents a potential improvement over other animal models of hepatic neoplasia.