Nasal planum tumors in cats and dogs.

Nasal Planum Cancer in Cats and Dogs

What are nasal planum tumors?
Nasal planum refers to the tip of the nose and cancer development in this area is associated with exposure to ultraviolet
light and lack of pigment. The most common type of cancer is called squamous cell carcinoma (SCC) which can be further
classified into SCC in situ (localized), superficial SCC, or deeply infiltrative SCC. They may be locally invasive but rarely
metastasize (spread to other organs). Other types of cancer have been reported in the nasal planum such as lymphoma,
fibrosarcoma, hemangioma, melanoma, mast cell tumor, fibroma, and eosinophilic granuloma.

How common are nasal planum tumors in cats and dogs?
Cancer of the nasal planum is rare in dogs but relatively common in the cat. It is usually observed in older, lightly
pigmented cats.

What are the symptoms of nasal planum tumors in cats and dogs?
Invasive SCC typically evolves over time (months to years) and progresses through several stages. In cats, SCC typically
originates in the cornified external surface of the nose whereas in dogs it usually occurs in the mucous membrane of the
nostril or the external planum.

How is the diagnosis made?
The most definitive way to confirm cancer is to perform a wedge biopsy. Because the nasal planum is so sensitive, pets
usually require brief general anesthetic. Advanced imaging such as CT (computed tomography) and MRI (magnetic
resonance imaging) have recently become valuable tools that evaluate the extent of the disease, providing guidance for
subsequent surgery and/or radiation therapy.

Does cancer cause pain in pets?
Pain is common in pets with cancer, with some tumors causing more pain than others. In addition to pain caused by the
actual tumors, pets will also experience pain associated with cancer treatments such as surgery, radiation therapy or
chemotherapy. Untreated pain decreases the pet's quality of life, and prolongs recovery from the illness, treatment or
injury. It is, therefore, essential that veterinary teams that are taking care of pets with cancer should also play a vital role
in educating pet owners about recognizing and managing pain in their pets. The best way to manage cancer pain in pets
is to prevent it, a term referred to as preemptive pain management. This strategy anticipates pain ahead of time and
administers pain medication before the pet actually experiences pain, thus ensuring the pet's maximum comfort.

To learn more about which tumors are likely to cause a lot of pain, how to recognize pain in pets with cancer and what
cancer pain management options are available for your pet, please visit the Cancer Pain Management section.

Is nutritional support important for pets with cancer?
Cancer cachexia (a term referring to progressive severe weight loss) is frequently observed in pets with cancer. Pets with
cancer lose weight partly because of lack of appetite and partly because of cancer-induced altered metabolism. Some of
the causes for decreased appetite are related to the cancer itself (for example, tumors may physically interfere with food
chewing, swallowing, and digestion process) and some may be related to the side effects of cancer treatment (for
example, some chemotherapy drugs cause nausea and vomiting, and radiation therapy can cause mouth inflammation).

Proper nutrition while undergoing cancer treatment is essential to maintain your pet's strength, improve survival times,
quality of life and maximize response to therapy. Adequate nutritional support was shown to decrease the duration of
hospitalization, reduce post-surgery complications and enhance the healing process. Additionally, pets with cancer need
to be fed diets specifically designed to provide maximum benefit and nutritional support for the patient. To learn more,
please visit the Cancer Nutrition section.

What are the treatment options for cats and dogs with nasal planum tumors?
Limiting exposure to the sun may prevent or slow down the course of the precancerous growths. Topical sunscreens don't
work effectively since they are easily licked off. Minimally invasive SCC can be managed effectively by a variety of
different treatment options, including cryosurgery, lasers, phototherapy, or intralesional carboplatin chemotherapy,
hyperthermia or radiation therapy. Deeply invasive SCC are resistant to these types of treatments. In cats, invasive
cancer can be completely removed with an acceptable cosmetic appearance outcome. This type of treatment is typically
the treatment of choice for invasive lesions that have not spread to the lip or surrounding skin. If the tumor cannot be
completely removed, radiation therapy after surgery is recommended to kill any remaining cancer cells left behind.

Are there any clinical trials for cats and dogs with nasal planum tumors?
There are no clinical trials specifically designed to treat this type of cancer but please click here to check if your pet may
qualify for clinical trials for general malignancy.

What is the prognosis for cats and dogs with nasal planum tumors?
The prognosis for early, noninvasive SCC is good. However, other sites of the nasal planum can develop additional
abnormal growths after localized treatment. More advanced stages of SCC can be successfully treated with aggressive
surgery but are less responsive to other forms of treatment. The cancer does not come back at 1 year in more than 80%
of cats with invasive SCC treated with surgery. Because the SCC in the nasal planum rarely metastasizes to other organs,
the pets can enjoy long lives.

Sources:

Withrow Stephen J, and David M. Vail. Small Animal Clinical Oncology. St Louis: Saunders Elsevier, 2007.
Morrison Wallace B. Cancer in Dogs and Cats: Medical and Surgical Management. Baltimore: Williams&Wilkins,
1998.