Canine Health Menu

Nasal Cancer

Issue Description
The most common type of cancers affecting the animal's nose are carcinomas and sarcomas, both of which are locally invasive. The most common sites for metastasis are the lymph nodes and the lungs, but can also include other organs.
Other Names
Canine Nasal Cancer, Nose Cancer


Causes
Nasal cancer has been chalked up to several different carcinogens. Some of the most common airborne ones are in pesticides, herbicides, kerosene, fossil fuel emissions (from gas and diesel engines, industry and the like), and cigarette smoke.

Symptoms
Signs vary but may include bleeding from the nose, nasal discharge,facial deformity from bone erosion and tumor growth, sneezing, or difficulty breathing, unilateral nasal and/or ocular discharge, epistaxis, stridor, loss of smell, loose teeth and sometimes pawing at the face.

Late-stage signs may include a facial deformity along the dorsal aspect of the maxillary bones or over the paranasal and frontal sinuses. Some cases develop a raised or pitting facial bone deformity.

Some cases may exhibit a firm or soft focal, raised mass protruding around or between the eyes. Some cases may have a palatine deformity from the softening and bowing out of the hard palate due to demineralization of the palatine bone and growth of the mass.

In every case of facial deformity, there is bone lysis and tumor invasion at that site. If the lesions extend into the brain, seizures and behavior changes are often exhibited.


Diagnosis
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 computed tomography (CT) scan. In order to definitively confirm cancer in the nasal cavity, a tissue biopsy should be obtained.

Treatment
Radiation therapy has become the preferred treatment. Its advantage is that it treats the entire nasal cavity together with the affected bone and has shown the greatest improvement in survival. The radiation therapy is typically delivered in 10-18 treatment sessions over the course of 2-4 weeks.

Prognosis
The prognosis is generally grave to very poor. Untreated dogs and cats usually die within two to seven months of diagnosis. If rhinotomy is the only treatment, survival is actually shorter. In selected cases that receive radiation therapy (plus or minus adjuvant therapy), survival can be raised to a range of eight to 25 months. The one-year treatment survival may be 40 percent and can go up to 80 percent in select cases. Half of the one-year survivors die in the second year. Palliative chemotherapy may improve clinical signs for a time but does not seem to extend survival.

A good case for radiation therapy is, sarcomas do better than carcinomas and respiratory adenocarcinomas do better than other carcinomas. Tumor size and location are also factors. Localized lesions in the rostral to middle part of the nasal passage do better; most are in the caudal two-thirds of the nasal passage. Lymphomas respond the best and low-grade chondrosarcomas have the potential to survive the longest.

Radiation therapy for nasal passage cancer is a difficult process for the patient and caregivers. The risk-benefit ratio must be weighed carefully in each case.


Dogs
Horse Herd