In a dog-based study, author Sunil Badve from Indiana University along with lead author Sulma Mohammed, a Purdue University scientist from the School of Veterinary Medicine, and team, made the discovery that might lead to better understanding of breast cancer progression and prevention for people and pets.
In the study, the researchers studied 212 tissue biopsies from 200 female dogs with tumours. "With a dog model, we could study these lesions and test different prevention modalities before it becomes a cancer." said Mohammed.
"Dogs develop these lesions spontaneously in contrast to other available models and are exposed to the same environmental risk factors as humans," said Mohammed. Then, the canine slides were compared to human specimens.
Mohammed said the focus of the study was not on the tumour but on the precancerous, or preneoplasia, lesions in tissue around the tumour. "We found that preneoplasia lesions are virtually identical, microscopically, in dogs and women," she said. "In fact, many of the slides were so similar it was often difficult to determine if they were from dogs or people without looking at the label.
"These shared features make the dog an ideal model to compare the breast lesions that will progress to cancer and those that will regress. Such a model will facilitate customized treatment and prevention strategies," she said.
The researchers determined that because of the frequency of lesions, their association with spontaneous mammary cancer and the resemblance to human lesions, dogs might be the ideal model to study human breast cancer progression as well as prevention and treatment.
Mohammed said that the dogs provide a more realistic comparison to humans than the mice and rat models, in part because the tumours developed spontaneously, just as in humans. "Unlike laboratory rodents, dogs share a common environment with people and, therefore, may be exposed to some of the same carcinogens.
Also, because dogs have a shorter life span than people, it is possible to study mammary lesions and invasive tumours that develop after a few years instead of decades," she said.
The study is published in the Journal of Cancer Epidemiology, Biomarkers, and Prevention.