Animal models of human breast carcinoma: canine and feline neoplasms

Abstract

Domestic animals develop spontaneously many of the diseases that also affect human beings, including cancer, and thus are excelent natural models of those diseases. The canine and feline mammary gland carcinoma is one of the natural models proposed by the World Health Organization because of its epidemiologic, clinical and morphologic similarities with human breast cancer. Incidence is high in both domestic species, which allows to perform statistically significant studies in short periods of time and risk factors are similar (including hormone-dependence). Biological behaviour of canine mammary gland tumors is malignant in some 50% of the cases, while more than 90% of feline tumors are malignant and characterized by rapid growth, invasion, ulceration and metastases. Although classification schemes of human, canine and feline mammary gland carcinomas are different, the histologic picture is qu!te similar, as well as prognostic factors (tumour size, lymph node metastases, and histological and nuclear degree, among others).