There is a strong correlation between early spaying and a reduced incidence of the disease. If mammary cancer is caught early, the treatment is more often successful. This article will help familiarize the cat owner with appearance and treatment of this deadly cancer. Any adult female cat can develop mammary cancer, but the average age is usually 10-14 years of age. Siamese cats appear to have a genetic predisposition for developing mammary cancer and are twice as likely to develop it as other breeds.
Unspayed females are at a much greater risk of developing mammary cancer.
Female cats that were spayed after having one to several heat cycles, with or without having kittens, are also at a greater risk than a cat that was spayed before her first heat cycle. Adenocarcinomas are very aggressive tumors and often metastasize to the surrounding lymph nodes and lungs. About one fourth of the tumors are ulcerated. The tumors are more common on the first front sets of mammary glands. In half of the cases, tumors are present in more than one gland.