title: Immunohistochemical characterization of canine prostatic carcinoma and correlation with castration status and castration time.
abstract: The purpose of this study was to characterize canine prostate cancer using immunohistochemical staining specific for acinar and urothelial/ductal tissue and correlate these results with the dogs' castration status/castration time. Seventy dogs with prostate cancer were included, 71% were castrated and 29% were intact. Compared with an age-matched control population, castrated dogs were at increased risk of prostate cancer, odds ratio 3.9. Immunohistochemical staining was performed on 58 cases. Forty-six of the 58 stained positive for cytokeratin 7 (CK 7) (ductal/urothelial origin) and one of the 58 stained positive for prostate-specific antigen. Dogs with CK 7-positive tumours were younger when castrated than dogs with CK 7-negative tumours, 2 versus 7 years (P = 0.03); dogs castrated at <or=2 years of age were more likely to be CK 7-positive (P = 0.009). These results show that most canine prostatic carcinomas are of ductal/urothelial, androgen-independent origin. This is consistent with the epidemiological findings, showing increased risk in castrated dogs. Canine prostate cancer may, therefore, not be a realistic model for the human disease.
authors.affiliation: University of Pennsylvania School of Veterinary Medicine, Departments of Clinical Studies and Pathobiology, Philadelphia, PA 19104-6010, USA. karins@vet.upenn.edu
authors.forename: K U
authors.initials: KU
authors.lastname: Sorenmo
authors.forename: M
authors.initials: M
authors.lastname: Goldschmidt
authors.forename: F
authors.initials: F
authors.lastname: Shofer
authors.forename: C
authors.initials: C
authors.lastname: Goldkamp
authors.forename: J
authors.initials: J
authors.lastname: Ferracone