Lung Cancer (Squamous Cell Carcinoma) in Cats

Metastatic Lung Tumor in Cats

The squamous epithelium is the outer layer of the epithelium, consisting of flat, scale-like cells. The epithelium is the cellular covering of all of the internal and external surfaces of the body, effectively protecting the organs, inner cavities and outer surfaces of the body in a continuous layer of multi-layered tissue. A squamous cell carcinoma of the lung is a type of metastasizing tumor that arises from the squamous epithelium in the lung cavity.

This is a rare form of primary tumor in cats. However, it has a high metastatic potential, especially if it reaches the regional lymph nodes.

Symptoms and Types

• Cough
• Lethargy
• Inability to perform normal physical actions
• Weight loss
• Lameness
• Increased respiration rate
• Coughing up blood

Diagnosis

You will need to give your veterinarian a thorough history of your cat's health and onset of symptoms. A standard physical examination will include routine laboratory tests, with a complete blood count, biochemical profiles, and urinalysis. The results of the blood tests may reveal an increased number of leukocytes or white blood cells (leukocytosis) in the blood, indicative of an invasion that the body is fighting against. Biochemistry profiles in some patients may show abnormally high levels of calcium (hypercalcemia).

Another diagnostic tool that your veterinarian can use to ascertain your cat's condition is an endoscope, a minimally invasive tubular device that can be inserted into the body without having to perform surgery in order to view the tumor up close and to take fluid and tissue samples from within the lungs. These samples can then be sent to a veterinary pathologist for further evaluation. The results of these tests usually provide an initial diagnosis. Your veterinarian will also take thoracic (chest) x-rays, which may show a single mass arising from a single focus. The trachea may appear to be displaced or compressed due to the presence of a mass, or tumor. In some patients a partial or complete airway obstruction may also be seen.

The only way to confirm a diagnosis of squamous cell carcinoma is to take a lung tissue sample (biopsy). This sample will be sent to a veterinary pathologist, who will cut into very small sections to examine under a microscope.

Treatment

Surgery is required for most patients. After consultation with a veterinary oncologist, chemotherapy may be advised for your cat, especially if the presence of tumor cells is suspected. However, a complete resection of the affected lung lobe is often the only way to stop the spread of this highly metastatic cancer. Such an intervention will provide the best opportunity for long-term survival of your cat. If lymph node involvement is suspected, a sample will be taken from the lymph nodes. If the lymph nodes are involved, your veterinarian may remove them all to prevent further dissemination of cancerous cells. Chemotherapy may be given before or after the surgery.

Living and Management

Overall prognosis is very poor in affected animals and untreated cats animals may only survive for three months or less. Even with treatment, overall survival time generally is not more than several months. The decision to go forward with surgery or chemical therapy will be based on the actual prognosis. In some cases, end of life pain management may be in order.

Always seek advice and instructions from a veterinary oncologist before giving chemotherapy medications, as these drugs are highly toxic to human health. Chemotherapy medications have the possibility of toxic side effects, so your veterinarian will need to closely monitor your cat's stability, changing dosage amounts as necessary.

After surgery, you should expect your cat to feel sore. Your veterinarian will give you pain medication for your cat to help minimize discomfort, and you will need to set up a place in the house where your cat can rest comfortably and quietly, away from other pets, active children, and busy entryways. Setting the cat litter box and food dishes close by will enable your cat to continue to care for itself normally, without exerting itself unduly. Use pain medications with caution and follow all directions carefully; one of the most preventable accidents with pets is overdose of medication.