Production of autochthonous prostate cancer in Lobund-Wistar rats by treatments with N-nitroso-N-methylurea and testosterone.

More than 50% of Lobund-Wistar (L-W) strain rats developed large, palpable prostate adenocarcinomas (PAs) following treatments with N-nitroso-N-methylurea (CAS: 684-93-5) and testosterone propionate [(TP) CAS: 57-85-2], and most of the tumor-bearing rats manifested metastatic lesions. The incubation periods averaged 10.6 months. Within the same timeframe, no L-W rat developed a similar palpable PA when treated only with TP. In L-W rats, TP acted as a tumor enhancement agent, with primary emphasis on the development of prostate cancer.