How Understanding Canine Mammary Tumors Could Help Scientists Studying Human Breast Cancer

Ask an experienced dog parent and they are likely to tell you that canine mammary tumors are common in dogs, particularly intact female and/or obese dogs, and that 50% of them are malignant.  Veterinarians treat canine mammary cancer in much the same way that human oncologists treat breast cancer, through surgery and biopsy of the tumor.  Then, follow-up treatment is recommended by a veterinary oncologist depending on the diagnosis.  Just as in malignant human breast cancer, canine malignant cancer has a poorer prognosis for outcome and there is demand for better basic science for cancer research to develop improved diagnostics and to catalyze new treatments for both species.

Increasingly, naturally-occurring canine mammary tumors are also being recognized as an important model for increasing scientific knowledge of cancer in both species because they have several significant features in common with human breast cancer.  Researchers believe that identifying new genome variants associated with canine mammary tumors and comparing them to human breast cancer presents an opportunity to learn more, faster to benefit both species.

An example of the win-win nature of this research is in place at the University of Pennsylvania School of Veterinary Medicine.  Dr. Karin Sorenmo, a veterinary oncologist, created The Shelter Canine Mammary Tumor Program to help local shelter dogs with mammary cancer access treatment and be placed in loving adoptive and foster homes.  Since 2019, Dr. Sorenmo and other researchers in the program have been able to accumulate datasets from the tumor samples that inspired creation of a new diagnostic tool veterinarians can use to better predict prognosis for dogs with mammary tumors, helping pet parents make informed decisions about treatment options.

Datasets like these also have the potential to reveal new genome variants associated with canine mammary tumors and the opportunity to compare those to variants in human breast cancer.  Those comparisons could provide direction to responsive targets for drug therapy and help overcome the significant failure rates of newly developed pre-clinical drugs.