ANIMAL-MODELS FOR THE PRENEOPLASTIC LESIONS OF THE PROSTATE

Objectives: Reliable and adequate animal models are required, not only for investigation of etiology, pathogenesis, and treatment of prostat e cancer, but also for chemoprevention of prostatic carcinogenesis. Me thods: Animal models for the study of premalignant changes in the pros tate are reviewed in the paper, with specific reference to the neonata lly estrogenized mouse model. Results: Neonatal treatment of newborn H an:NMRI mice with synthetic nonsteroidal estrogen, diethylstilbestrol (DES; 2 mu g/pup on days 1-3 after birth) promoted hyperplastic and dy splastic changes in the periurethral region of the prostate at the age of 9-18 months. Dietary soy partially inhibited the development of pr ostatic dysplasia in these neonatally estrogenized animals, which may be due to phytoestrogens contained in soy-rich food. Conclusion: Prost atic cancer and its possible precursors develop spontaneously, or can be induced by different chemical and hormonal manipulations in certain animal species and strains. Neonatal estrogenization of the mouse res ults in prostatic dysplasia, which can be partially prevented by dieta ry soy. There are morphological similarities between human prostatic i ntraepithelial neoplasia (PIN) and dysplastic changes in rodent prosta tes, but more data is needed before these dysplastic lesions can be co nsidered equivalent to human PIN.