Oral Squamous Cell Carcinomas In Cats

The most common malignant oral tumor in cats is the oral squamous cell carcinoma, which typically affects middle-aged to older animals[1]. Tumors typically arise under the tongue or on the gums but can also affect the tonsils or throat area.  Tumor invasion into underlying bone is common.

Does My Cat Have an Oral Squamous Cell Carcinoma?

Warning signs of this tumor typically involve changes in behavior associated with the mouth area.  Paying close attention to the inside of your cat’s mouth during big yawns, as well as noting changes in play and eating habits are the best way to identify potential problems as early as possible.

Signs & Symptoms of Oral Squamous Cell Carcinomas

If your cat displays any of these signs or symptoms they could have an oral squamous cell carcinoma, and you should schedule an examination with your primary care veterinarian as soon as possible.

• Excessive Drooling – Have you noticed that your cat has been drooling more? Have you noticed any blood in their saliva?
• Difficulty Eating – Have you noticed your cat is eating less because they has difficulty chewing?
• Halitosis – Do you notice a significant change in the smell of your cat’s breath? Does the bad breath persist even after teeth brushing?
• Difficulty swallowing or chewing (depending on location) – Is your cat having trouble when trying to drink water, eat, or play with their toys?
• Weight Loss – Has there been a significant and sudden decrease in your cat’s weight?
• Loose Teeth – Are your cat’s teeth are loose or falling out?
• Oral Bleeding – Has your cat had significant episodes of bleeding from the mouth?

Diagnosis & Staging

Diagnostics tests for feline oral squamous cell carcinomas typically include one or more of the following:

• Routine bloodwork
• Biopsy
• Urinalysis
• Chest radiographs (not as common)
• CT scan of the oral cavity and neck
• Fine needle aspirates of enlarged lymph nodes

Treatment Options for an Oral Squamous Cell Carcinoma

An oral squamous cell carcinoma diagnosis in your cat can be unexpected and frightening, but there are some treatment options available. The best treatment option for you and your cat will be determined by tumor location and size, and can be explained in detail by a board certified specialist in veterinary medical or radiation oncology.

Surgery
Surgery for oral squamous cell carcinoma in the cat is very difficult because of typical tumor size and location. Recurrence is virtually certain if the entire tumor and all cancer cells cannot be removed.

Chemotherapy
Chemotherapy has been shown to have minimal effects against oral squamous cell carcinomas in cats but has occasionally been beneficial when combined with other treatment options such as radiation therapy.

Palliative Therapy
Palliative therapies such as antibiotics and painkillers can help maintain quality of life but do not slow the progression of the oral tumor.

Radiation Therapy

Before the introduction of stereotactic radiation (SRS/SRT) in veterinary medicine, conventionally fractionated radiation therapy (CFRT) was the most common type of radiation prescribed. CFRT can be used alone or follow a surgery to remove oral squamous cell carcinoma where some cancerous cells remain. Shorter treatment protocols consisting of smaller numbers of large doses of radiation, often called “palliative radiation,” may be prescribed for cats with oral squamous cell carcinoma as well.  Both CFRT and conventional palliative radiation can treat in ways that surgery or chemotherapy can’t but there is risk of damaging normal, healthy tissue that surrounds the tumor because of low precision. There are also multiple anesthetic events and prolonged courses of treatment with CFRT.  Many cats undergoing CFRT or palliative radiation for oral squamous cell carcinoma are reluctant to eat on their own and require feeding tubes.

Stereotactic Radiation (SRS/SRT)
At PetCure Oncology, our centers offer CFRT and conventional palliative radiation as well as the newer and more advanced forms of radiation therapy like stereotactic radiation (SRS/SRT). Unlike traditional radiation therapy, SRS/SRT can deliver high doses of radiation with sub-millimeter precision. This means:

• Maximum damage to the tumor and minimal collateral damage to healthy tissues nearby
• Fewer treatment sessions compared to CFRT—patients require only 1-3 sessions, which means fewer anesthetic events, less risk, and less disruption to your schedule
• Potential for quicker recovery with fewer side effects
• Ability to treat tumors previously considered untreatable with radiation
• PetCure Oncology’s radiation oncologists are experienced using SRS/SRT to treat cats with oral squamous cell carcinomas
• Feeding tubes are still recommended for many cats with oral squamous cell carcinoma that receive SRS/SRT

Oral Squamous Cell Carcinomas in Cats: Life Expectancy, Survival & Prognosis

Unfortunately, the overall prognosis for cats with oral squamous cell carcinoma is guarded. Survival usually ranges from 3-6 months with treatment, but can be longer depending on tumor size, stage and location as well as the type of treatment pursued.

As with any cancer, the earlier a feline oral squamous cell carcinoma is diagnosed and treated, the more likely it is that treatment will provide benefit.

If your pet has been diagnosed with cancer, contact our Pet Advocates at (833) PET-HERO or your local PetCure Oncology center. Our team members are ready to help answer your questions.

Reviewed by: Dr. Glenna Mauldin DVM, MS, DACVIM

[1] Stebbins, K. E., Morse, C. C., & Goldschmidt, M. H. (1989). Feline Oral Neoplasia: A Ten-Year Survey. Veterinary Pathology, 26(2), 121-128. doi:10.1177/030098588902600204

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