Feline Sinus Cancer

Sinus cancer in cats usually occurs as nasal tumors in the nostrils; as the cancer progresses it may spread to the cat's sinuses. Sinus cancer isn't a very common cancer, and its symptoms can remain hidden for as long as five years while the disease progresses.

Causes and Types of Feline Nasal Tumors

Vets believe that inflammation of the mucous membrane that forms the nasal and sinus lining may be a causal factor in feline sinus cancer. Cats who develop nasal tumors usually have a medical history of upper respiratory infections.

There are two common types of nasal tumors in cats. The first is lymphoma, which occurs when cancerous tumors grow from the cells of lymph tissue. The second is carcinoma, which occurs when cancerous tumors grow in the epithelial, or skin, cells.

Diagnosing Feline Sinus Cancer

To diagnose feline sinus cancer, your vet will look for nasal tumors. Symptoms of cat nasal tumors can include sneezing and upper respiratory discharge; in severe cases bleeding from the nostrils and disfigurement of the face can occur. Nasopharyngeal tumors, which occur in the upper throat, may cause changes in voice, labored breathing and snoring.

If your vet discovers tumors, he'll perform some of the following tests to determine whether or not they're cancerous:

  • Complete blood count
  • Cytological examination of the lymph nodes
  • Chest X-rays, in case the cancer has spread to the lungs
  • A biopsy of the tumor cells to determine if they're malignant
  • CT scans, X-rays or MRIs of the nasal cavity and sinuses

Treating Feline Nasal Cancer

Chemotherapy is somewhat effective in the treatment of feline nasal lymphoma. Cats suffering from feline leukemia virus don't respond as well to treatment. They run the risk of systemic failure due to the aggressive nature of cancer treatments. Local radiation and systemic chemotherapy are used in combination for the treatment of nasal lymphomas in cats.

Nasal carcinomas are more difficult to treat. Surgery on this type of tumor usually leads to post surgical survival for two to five weeks. Nasal carcinomas usually can't be accessed surgically, because they grow so deep within the nasal cavity and sinuses. Vets don't know much about using radiation treatment on the nasal cavities and sinuses of cats, so this treatment, while often used, may carry unknown risks.

If your cat's nasal carcinoma is inaccessible to the veterinary surgeon, he may recommend using a radiation treatment that combines orthovoltage and megavoltage therapy. If your cat's tumors are accessible and there's a good chance that your veterinary surgeon can remove them, he may still recommend that your cat undergo post-surgical radiation treatment.

Feline sinus cancer often carries a poor prognosis, usually because the disease has generally progressed into the later stages before owners notice symptoms. Side effects of radiation treatment can include bone changes and corneal ulcers. Surgery doesn't greatly improve your cat's chances of survival with sinus cancer. Cats with cancerous nasal tumors are usually euthanized within eight weeks of diagnosis.