Naturally-Occurring Canine Mammary Tumors as a Translational Model for Human Breast Cancer

Abstract

Despite extensive research over many decades, human breast cancer remains a major worldwide health concern. Advances in pre-clinical and clinical research has led to significant improvements in recent years in how we manage breast cancer patients. Although survival rates of patients suffering from localized disease has improved significantly, the prognosis for patients diagnosed with metastatic disease remains poor with 5-year survival rates at only 25%. In vitro studies using immortalized cell lines and in vivo mouse models, typically using xenografted cell lines or patient derived material, are commonly used to study breast cancer. Although these techniques have undoubtedly increased our molecular understanding of breast cancer, these research models have significant limitations and have contributed to the high attrition rates seen in cancer drug discovery. It is estimated that only 3-6% of drugs that show promise in these pre-clinical models will reach clinical use. Models that can reproduce human breast cancer more accurately are needed if significant advances are to be achieved in improving cancer drug research, treatment outcomes, and prognosis. Canine mammary tumors are a naturally-occurring heterogenous group of cancers that have several features in common with human breast cancer. These similarities include etiology, signaling pathway activation and histological classification. In this review article we discuss the use of naturally-occurring canine mammary tumors as a translational animal model for human breast cancer research.

Comparative Analysis of the Development of Acquired Radioresistance in Canine and Human Mammary Cancer Cell Lines

“…These neoplasms represent ~50% of all canine tumors ( 1 ), of which 50% are malignant ( 2 – 4 ). Due to similarities in clinical features, relative age of onset, risk factors and tumor biology, canine mammary tumors (CMT) represent an excellent comparative and translational model for human breast cancer (HBC) ( 5 – 7 ). Gene expression profiles of primary ( 8 ) and metastatic ( 9 ) CMT have also shown similarities with HBC profiles, providing evidence that canine models can be utilized to help understand the genetic mechanisms of carcinogenesis in humans and dogs ( 4 , 10 , 11 ).…”

ANK2 Hypermethylation in Canine Mammary Tumors and Human Breast Cancer

“…Canine mammary tumors (CMT) are the most common neoplasia diagnosed in female dogs and are found to be malignant in approximately 50% of cases [ 1 , 2 , 3 , 4 ]. Apart from the clear veterinary benefit to understanding the nature of this cancer more clearly, studying CMT can also be beneficial in the field of comparative oncology [ 5 , 6 , 7 ].…”

Canine mammary cancer diagnosis from quantitative properties of nonlinear optical images

“…We studied biopsies of mammary tissues from female dogs. The canine mammary tissue provides a good comparison to the human breast tissue and it shows the advantage of not presenting great differentiation of collagen content in the tissue throughout the life of the animal [28,[33][34][35]. The mammary tissue samples were obtained through biopsy procedures from animals under cancer treatment at the Federal University of Minas Gerais (UFMG) Veterinary Hospital.…”