My cat has squamous cell carcinoma | Dr. Justine Lee, DACVECC, DABT, Board-Certified Veterinary Specialist

Posted by justinelee in Animal Safety, Blog, Pet Health

If your cat was just diagnosed with squamous cell carcinoma (commonly abbreviated “SCC”), I can whole-heartedly empathize. In this blog, I share my own story, along with some important information for cat owners to know if their cat was just diagnosed with this horrible cancer.

My own 19-year-old cat, Seamus, was just recently diagnosed with SCC last month, and I’m heartbroken. Seamus was previously diagnosed with chronic kidney failure (CKF) and so I weighed him once a month for years. I wanted to make sure he maintained his weight. Well, last month, he lost 0.7 pounds, and I instantly knew something more severe was going on. That’s when I did a complete physical exam and found a fast growing tumor in his mouth.

I took him to our board-certified veterinary dentist at my specialty clinic, where he was sedated and put under general anesthesia for dental x-rays, lymph node aspirate (for cytology), extraction of tooth and biopsy of the mass. Unfortunately, days later, he was diagnosed with SCC on the biopsy and lymph node aspirate.

SCC is one of the most common cancers seen in cats, and accounts for approximately 10% of the type of cancers that cats get. Unfortunately, the most common location that cats get SCC is in the mouth, which is hard for pet owners to be able to “see” it. Unfortunately, this is a really rapid, fast-growing cancer and is very invasive (which means it grows into the nearby tissue and lymph nodes). While it rarely spreads to other parts of the body, it can grow so quickly and cause pain and discomfort that it prevents cats from eating. Often, cats will express interest in food – in other words – they’ll still come to the food bowl, but then they turn away or eat only a few bites before giving up due to oral pain. That’s why it’s so important to diagnose it as soon as possible so treatment can started immediately.

Clinical signs of SCC in cats include:

• Drooling (even discolored brown drool)
• Bad breath (halitosis)
• Weight loss
• Not eating
• Frequent tongue movement or licking
• Dropping food
• Swelling on the side of the jaw (resulting in asymmetry)
• Pain on opening the mouth

Unfortunately, any aged cat can get SCC, but in research studies, the average age was 12.5 years of age (range 3-21 years of age). Some studies have looked at environmental toxins like tobacco smoke having an increased risk for cats developing SCC. For cat owners who smoked 1-19 cigarettes a day, their cats had a statistically significant 4X increase in the risk of SCC compared to non-smoking households. (No, I don’t smoke, and even my cat got SCC). In another study, cats that wore flea collars also had a statistically significant 5X increased risk of SCC. The same study that evaluated smoke exposure also found an increase in SCC in cats that frequently ate canned cat food (compared to those that ate dry food). This may be related to the nutrient content of these foods, the chemicals used in canned food, or even the hypothesis that cats that ate dry food have less tartar buildup and less dental disease. There is some thought that chronic inflammation or chronic dental disease may be a causative predisposing factor for SCC.

Diagnosis of SCC is typically based on:

• Oral exam
• Physical examination
• Blood work (as an elevated calcium level can sometimes be seen)
• Dental x-rays (which typically need to be done under general anesthesia) which may show a “lytic” or eaten away appearance to the bone
• Biopsy (which needs to be done under general anesthesia)
• Cytology of the lymph node (where a small needle is used to aspirate cells out)
• X-rays of the chest to make sure cancer hasn’t spread elsewhere

Treatment
Unfortunately, there isn’t much treatment or advances with treating SCC in cats, as it’s so aggressive. While surgery and radiation therapy can be considered, along with chemotherapy, they have been often unsuccessful with a poor long term survival. Only 10% of cats survive to 1 year, with most cats surviving an average of 3 months even with aggressive therapy. Without treatment, the average survival is only about one month.

So, what did I do as a veterinary specialist when my cat was diagnosed?

My goal was to preserve his quality of life. To spoil him. To make each surviving day a good quality of life where Seamus was happy. That meant keeping him on pain medications (such as buprenorphine and gabapentin). Since the mass is in the mouth, it’s often hard to pill your cat. And as my cat had a really painful mouth, I elected to use Simbadol (which is a once a day injection that lasts 24 hours) – your veterinarian will have to administer this, but it can be used for a few days initially to help. I also used a long acting antibiotic injection called Convenia for 2 weeks (1 injection, 7 days apart), as I was worried that there was a bacterial infection in his mouth from the decaying cancer tissue.

Lastly, canned food and cat treats…whatever Seamus wanted to eat. Here, my favorite treats that he loved:

• Bonito flakes
• Gerber Meat-based baby food (e.g., chicken, turkey, chicken/veggie blends)
• Canned tuna in water
• Shrimp (frozen shrimp that was microwaved to cook it)
• Greenies cat treats
• Royal Canin Savory food

What about prevention?
While SCC is aggressive, the sooner it is found and the smaller it is at the time of diagnosis, the more treatment options are available. That’s one of the reasons why daily dental home care, regular oral exams and regular dental cleaning increase the chances of finding SCC early. When in doubt, talk to your veterinarian about this, as dental health is so important!

Most importantly, consider humane euthanasia when you feel like your cat’s quality of life is deteriorating. For me, the signs below indicate a poor quality of life. When in doubt, talk to your veterinarian.

• Not eating for 2 days in a row
• Continued weight loss
• Hiding
• Not moving
• Difficulty breathing
• Sleeping all the time

I wish I had better news for you. I’m right there with you, heartbroken with my old man. When in doubt, talk to a board-certified veterinary dentist or veterinary oncologist for more information… and hugs to your cat. This veterinarian’s thinking of you.

More information can be found here at Cornell’s website. Further information for your veterinarian (with links to the studies) can be found at DVM360.