Every year, thousands of cats develop tumors that appear to be linked to routine vaccination and other injections. These injection site–associated sarcomas (ISASs) are typically more aggressive than sarcomas that occur spontaneously. In addition, ISASs often require more intensive treatment and show a higher risk of recurrence after surgical removal. For these reasons, accurate diagnosis of the tumor subtype can significantly affect the outcome for sarcoma patients.
With Morris Animal Foundation funding, researchers at North Carolina State University’s College of Veterinary Medicine (CVM) are developing a technique that will help veterinarians distinguish between ISASs and spontaneous sarcomas in cats. Success in distinguishing between these cancers would not only provide for more appropriate treatment and a better chance for a positive outcome but may also provide clues as to the underlying mechanism(s) for cancer development.
“In human medicine, knowledge of the pattern of chromosome abnormalities in tumors from different patients has led to sophisticated DNA-based methods for diagnosing cancer and determining optimal treatment strategies,” says Dr. Rachael Thomas, a research assistant professor in the CVM Department of Molecular Biomedical Sciences and the lead researcher on the study.
But, so far, there have been very few DNA-based studies of feline cancer, and tests for determining optimal treatment strategies have yet to be developed. As such, Dr. Thomas’s study is breaking new ground. The researchers are using array comparative genomic hybridization technology to compare the patterns of chromosome abnormalities in ISASs with those of spontaneous feline sarcomas. This technology compares DNA from tumors to DNA from healthy cats and identifies regions that are duplicated or lost.
“Comparing the patterns of gains or losses of particular DNA fragments from different patients with either ISASs or spontaneous sarcomas will allow identification of abnormalities that are present in one subtype and not the other, which can therefore assist with diagnosis,” Dr. Thomas says.
Knowledge of these unique chromosomal abnormalities could provide a means to define which subtype of sarcoma a given patient has, and to do so at the early stages of the disease when it can be most appropriately treated.
“This may provide crucial information to help guide the owner and veterinarian as to the best approach to treatment and, in the longer term, help us to understand why these tumors occur,” Dr. Thomas says.
Dr. Thomas is a member of the Oncology and Clinical Genomics Cores in the Center for Comparative Medicine and Translational Research (CCMTR). Located on NC State’s Centennial Biomedical Campus, the CCMTR is a community of more than 100 scientists from five NC State colleges. These investigators are involved in collaborative ”One Medicine” studies with government, private, and other academic researchers to advance knowledge and practical applications that improve the health of animals and humans.