Promotive effect of diethylstilbestrol on urethan-induced mouse lung tumorigenesis

The effect of diethylstilbestrol (DES) on urethan-induced mouse lung tumori genesis was assessed by a single intraperitoneal injecting of urethan (50 m g/kg) or/and multi intramuscular injecting of DES (5 or 50 mg/kg). All mice were sacrificed 18 weeks after administration, and the lung tumors were ex amined histopathologically. DES did not produce an elevated lung tumor resp onse when administered alone, but it produced a statistically significant e nhancement of incidence of tumors, average number of tumors, incidence of c ancers and constituent ratio of malignant tumors when given in conjunction with urethan. The results indicated that DES may be a promoter in lung tumo r formation. (C) 2000 Elsevier Science Ltd. All rights reserved.