title: Adenocarcinomas of the prostate induced by N-nitroso-N-methylurea in rats pretreated with cyproterone acetate and testosterone.
abstract: Prostatic adenocarcinomas were induced in 5 out of 20 Wistar rats upon a single administration of 50 mg/kg N-nitroso-N-methylurea (NMU). The rats were pretreated with a daily dose of 50 mg/kg cyproterone acetate for 3 weeks followed by 3 daily injections of 100 mg/kg testosterone. All tumours developed in the dorsolateral prostate and were invasively growing. In 2 cases distant metastases were found. Three proliferative lesions classified as carcinomas in situ were also found in the dorsolateral prostate. A total of 7/20 animals (35%) carried an adenocarcinoma and/or a carcinoma in situ. In addition, 6 epithelial hyperplasias were observed in the dorsolateral and 1 in the ventral prostate of non-tumour-bearing rats. The method described may provide a good animal model for cancer of the prostate and lead to a better understanding of prostatic carcinogenesis.
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced*; D000818:Animals; D002278:Carcinoma in Situ / Q000139:chemically induced*; D003043:Cocarcinogenesis; D003534:Cyproterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D017373:Cyproterone Acetate; D008297:Male; D008770:Methylnitrosourea; D008954:Models, Biological; D009362:Neoplasm Metastasis; D009374:Neoplasms, Experimental / Q000139:chemically induced; D009607:Nitrosourea Compounds; D011471:Prostatic Neoplasms / Q000139:chemically induced*; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D009607:Nitrosourea Compounds; D013739:Testosterone; D017373:Cyproterone Acetate; D008770:Methylnitrosourea; D003534:Cyproterone