|What are nasal cavity tumors?
The nasal cavity is a large air-filled space above and behind the nose. Paranasal sinuses are air-filled spaces that
communicate with the nasal cavity. The most common type of cancers affecting this region are carcinomas and sarcomas,
both of which are locally invasive. Carcinomas form in the lining of the nose and include adenocarcinoma, squamous cell
carcinoma and undifferentiated carcinoma subtypes. Sarcomas form in the cartilage, bone or connective tissue within the
nose. Although less frequent, other tumor types have been reported in nasal cavity including melanoma or mast cell
tumors. The metastatic rate (spread to other organs) is considered low at the time of diagnosis but can be as high as 50%
at the time of death. The most common organs to which the tumors spread are the lymph nodes and the lungs, but can
also include other sites like bone, kidneys, liver, skin, or the brain.
How common are nasal cavity tumors in dogs?
Tumors in the nasal cavity and paranasal sinuses are not very common and account for approximately 1% of all tumors in
dogs. However, approximately 80% of these tumors are malignant and have a poor long-term prognosis. The average age
of dogs with this disease is about 10 years and medium to large breeds may be at higher risk.
What are the symptoms of nasal cavity tumors in dogs?
The average duration of symptoms before diagnosis is 3 months and include bleeding from the nose, nasal discharge,
facial deformity from bone erosion and tumor growth, sneezing, difficulty breathing, or eye discharge due to tumor
obstruction of the ducts. Nasal blleeding or discharge will often occur in one nostril but may affect both sides over time.
Some of these symptoms overlap with other medical conditions such as fungal infection, foreign body, or inflammation but
as the tumor grows, signs such as facial deformity, swelling or eye protrusion may be observed. In cases where the nasal
tumor is close to the brain, the dog may suffer from seizures or behavior changes.
How is the diagnosis of nasal cavity tumors made?
To confirm a diagnosis of nasal tumors, the veterinarian will typically perform a physical exam, imaging and biopsy.
Advanced imaging techniques such as CT scan or MRI are superior tools (but expensive) for evaluating the extent of
tumors in the nasal cavity as well as for planning radiation therapy treatment. Standard X-rays are still acceptable and
readily accessible imaging tools but their resolution and level of anatomical detail are not as good as for a CT scan. In
order to definitively confirm the presence of a nasal tumor, a tissue biopsy should be obtained. For nasal tumors, there is a
variety of different techniques that can be used. These include vigorous nasal flushings in order to dislodge pieces of
tumor or transnostril aspiration, a technique that passes a needle through the nostril into the tumor. If nearby lymph nodes
appear swollen, they should be sampled for cytology to test for the presence of cancer cells that might have spread. It is
estimated that at the time of diagnosis, ~6% of dogs have tumor cells that spread to the lymph nodes. Once diagnosis is
confirmed as cancer, it is usually recommended to stage the disease (determining how extensive it is) so that an
appropriate treatment plan can be developed by the veterinary oncologist. Staging of nasal tumors usually include lymph
node aspiration (to determine whether the tumor spread to the nearby lymph nodes), chest radiographs (to determine
whether the tumor spread to the lungs) and blood tests/urinalysis (to determine the overall health of the pet and if the pet
is well enough to undergo treatment).
Does cancer cause pain in dogs?
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 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 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 nasal cavity tumors in dogs?
Because nasosinal cancer begins to invade the bone early, surgery (called rhinotomy) alone is not sufficient to control the
cancer. Radiation therapy directed to the affected area is currently the treatment of choice for canine nasosinal tumors and
has been shown to improve survival times (see below prognosis section). The advantage of radiation therapy is that it
treats the entire nasal cavity together with the affected bone and has shown the greatest improvement in survival. At this
time, it is uncertain whether surgical removal of the tumor prior to radiation therapy provides even better benefit to the
dogs. The radiation therapy is typically delivered in 10 -18 treatment sessions over the course of 2-4 weeks, thus requiring
a great deal of commitment from pet owners to complete the course of radiation treatment. It has been shown that
megavoltage radiation therapy results in better survivals compared to cobalt radiation therapy. The use of CT imaging prior
to initiating radiation therapy can be of tremendous help for effectively directing radiation only toward the affected areas
while sparing normal healthy tissues.
Results from a previous study suggest that combining cisplatin, a chemotherapy drug, with radiation may improve the dog's
survival compared to radiation therapy alone. This study evaluated slow-release cisplatin in combination with radiation
treatment (using a 6 MV linear accelerator) in 13 dogs with malignant nasal cavity tumors. Cisplatin was administered using
an open-cell polylactic acid polymer and implanted intramuscularly at a distant site as a slow release delivery system. This
delivery method of cisplatin did not cause any systemic toxicity in combination with radiation, and a local tissue reaction was
seen in only two dogs. Acute radiation-therapy side effects to normal tissue were not enhanced. The combination of
radiation and cisplatin resulted in a median survival of 580 days, which appears longer compared to historical data on dogs
who only received radiation alone (without cisplatin) with a median survival of 325 days (Lana, Vet Radiol Ultrasound,1997).
For dogs unable to undergo radiation therapy, cisplatin chemotherapy is an option but one with limited efficacy that does
not improve survival times. If the tumor is small and did not invade surrounding tissues, surgical removal may be an option;
however, very few dogs meet this criteria at the time of diagnosis. As mentioned above, surgical removal of large and/or
invasive tumors does not provide any substantial benefit.
What are the radiation therapy side effects?
Unfortunately, radiation therapy will affect some normal tissues that cannot be excluded from the radiation field (the area
scheduled for irradiation). The amount of damage will depend on the daily dose of radiation, total radiation and how much
of the tissues is being treated. Immediate side effects of radiation therapy usually include inflammation of the oral cavity
(mouth), inflammation of the nasal cavity, shedding of the skin, and eye dryness. It is very important to prevent any
additional damage to the area caused by the pet's pawing or licking so Elizabethan collars should be used as needed.
These immediate side effects usually disappear 2-8 weeks after therapy and can be treated with antibiotics, pain
medication and/or artificial tears if needed. Inflammation in the mouth can be treated with oral rinse solutions (e.g. a weak
tea solution, chlorhexidine rinse, or mixture of viscous lidocaine, liquid diphenhydramine, and magnesium hydroxide). If the
mouth inflammation is severe and the dogs are unable to eat, short-term feeding tubes may have to be inserted to support
the proper nutritional intake. Late side effects of radiation therapy are more long lasting but can be prevented with proper
planning. The affected areas can include the eye lens (cataracts), eye cornea (inflammation, dryness), eye uvea
(inflammation), eye retina (bleeding and wasting), neuronal tissue (possibly causing seizures), bone, and skin. These late
complications develop months to years after therapy and are generally not reversible.
How do I find a qualified veterinary oncologist?
To locate a qualified veterinary oncologist worldwide who can discuss with you appropriate cancer treatment plan for your
pet's cancer condition, please visit the "Locate a veterinary oncologist" section.
Are there any clinical trials investigating new treatments for nasal cavity tumors in dogs?
There are currently two clinical trial in dogs with nasal cancer. To learn more about this trial, please visit the Clinical Trials
for Nasal Cancer in Dogs section.
Additionally, there are several clinical trials available for cats and dogs with any tumor type for which your pet may qualify.
To learn more these trials (which are partially or fully funded by the institutions), please visit the Dog Clinical Trials (any
tumor type) or Cat Clinical Trials (any tumor type) section.
To learn more about veterinary clinical trials in general, please visit the Pet Clinical Trials section.
What is the prognosis for dogs with nasal cavity tumors?
One study of 139 dogs showed that without treatment, the average survival time is 95 days. Another study showed that
dogs who underwent surgery alone had median survival 3-6 months, which is comparable to that reported for no treatment.
Prognosis of dogs who show symptoms of nose bleeding appears to be worse (median survival of 88 days) compared to
those without it (medial survival of 224 days). The median survival time after full course of radiation treatment alone ranges
from 8 to 19.7 months, and 43-60% of dogs are alive 1 year after radiation and 11-44% 2 years post-radiation. The use of
CT imaging to plan radiation treatment can increase the survival range to 11-19.7 months. Although radiation therapy
alone is able to provide local control of nasosinal tumors for approximately 10 months, and thus prolongs the patients'
overall survival, most dogs will eventually die as a result of local disease progression. New approaches to control these
tumors need to be developed to further improve the response and overall survival.
Several characteristics are associated with poorer outcomes (shorter survival) in dogs with nasosinal tumors such as being
over 10 years old, having a tumor-induced facial deformity, presence of lymph node or other organ metastasis, or lack of
resolution of clinical signs after radiation therapy.
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|Nasal Cavity (Nose) Cancer in Dogs