Induction of Malignant Kidney Tumors in Rats with Streptozotocin

Diabetes was induced in rats with streptozotocin and alloxan and the tumorogenic effects of these two compounds were compared. One hundred thirty Lewis and Sprague-Dawley rats survived the induction of diabetes with streptozotocin. Fifty-six of these animals were sacrificed within 8 months of streptozotocin administration and three were found to have renal tumors. Twenty-four of 74 (30.8%) streptozotocin rats sacrificed more than 8 months after the induction of diabetes had grossly visible renal tumors. The lesions were epithelial in type and, although rarely invasive, had malignant cytological characteristics. Two of these animals had gross tumor spread to the liver and lungs. Forty % of the renal tumors were bilateral. No tumors were found in 72 rats surviving diabetic induction with alloxan and 260 littermate controls. Streptozotocin (an N-nitrosomethylamide) is chemically related to dimethylnitrosamine (an N-nitrosodimethylamine), a known carcinogenic agent in rats. It is concluded that streptozotocin can induced renal cancer in rats.