title: Canine mammary gland tumours; a histological continuum from benign to malignant; clinical and histopathological evidence.
abstract: This study describes the clinical and histopathological findings in dogs with mammary gland tumours, and compares the histopathological and clinical evidence consistent with progression from benign to malignant to human breast cancer epidemiology. Clinical and histopathological data on 90 female dogs with 236 tumours was included. Dogs with malignant tumours were significantly older than dogs with benign tumours (9.5 versus 8.5 years), P = 0.009. Malignant tumours were significantly larger than benign tumours (4.7 versus 2.1 cm), P = 0.0002. Sixty-six percent had more than one tumour, and evidence of histological progression was noted with increasing tumour size. Dogs with malignant tumours were significantly more likely to develop new primary tumours than dogs with benign tumours, P = 0.015. These findings suggest that canine mammary tumours progress from benign to malignant; malignant tumours may be the end stage of a histological continuum with clinical and histopathological similarities to human breast carcinogenesis.
authors.affiliation: School of Veterinary Medicine of the University of Pennsylvania, Philadelphia, PA 19104, USA. karins@vet.upenn.edu
authors.forename: K U
authors.initials: KU
authors.lastname: Sorenmo
authors.forename: V M
authors.initials: VM
authors.lastname: Kristiansen
authors.forename: M A
authors.initials: MA
authors.lastname: Cofone
authors.forename: F S
authors.initials: FS
authors.lastname: Shofer
authors.forename: A-M
authors.initials: AM
authors.lastname: Breen
authors.forename: M
authors.initials: M
authors.lastname: Langeland
authors.forename: C M
authors.initials: CM
authors.lastname: Mongil
authors.forename: A M
authors.initials: AM
authors.lastname: Grondahl
authors.forename: J
authors.initials: J
authors.lastname: Teige
authors.forename: M H
authors.initials: MH
authors.lastname: Goldschmidt
mesh_terms: D000230:Adenocarcinoma / Q000662:veterinary; D000236:Adenoma / Q000662:veterinary; D000818:Animals; D002277:Carcinoma / Q000662:veterinary; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D015674:Mammary Neoplasms, Animal / Q000473:pathology*; D018198:Mixed Tumor, Malignant / Q000473:pathology / Q000662:veterinary*; D009369:Neoplasms / Q000473:pathology / Q000662:veterinary*; D018193:Neoplasms, Complex and Mixed / Q000473:pathology / Q000662:veterinary; D009375:Neoplasms, Glandular and Epithelial / Q000662:veterinary; D012189:Retrospective Studies