Arianna Bartlett, a PhD candidate at the Baker Institute at Cornell University, is studying feline mammary cancer. Mammary cancer is the third most common feline cancer, after lymphoma and skin cancer. It occurs most frequently in cats over 10 years old. Intact female cats not only have a high rate of breast cancer, but 85% of the time, the cancers are malignant (spaying lowers the risk of mammary cancer).
According to breastcancer.org, women have about a 13% chance of developing invasive breast cancer. The National Centers of Biotechnical Information states that about 60% to 80% of breast tumors are benign. Unlike cats, humans usually have regular screenings, so a tumor may be detected earlier than in cats.
With funding partially provided by the Cornell Feline Health Center, Bartlett is taking a comparative look at human breast cancer and factors that influence its development (both carcinogens and genetics), and analyzing the differences between feline cells and those of other animals that do not live inside with people. Horses, for example, have a low rate of mammary cancer for reasons that are as yet unclear.
Bartlett is working mostly with cell cultures. When mammary cells from both horses and cats are exposed to dimethylbenz(a)anthracene (DMBA), a carcinogen known to cause mmmary cancer, their responses are different. The equine cells tend to simply die off, which means they aren’t mutating into cancer cells. In contrast, the feline cells repair the damage from the carcinogen but leave themselves open to future mutations that might lead to cancer.
With her emphasis on the genetics of microRNAs, Bartlett hopes to find treatments that might help both cats and people in the future.