The last thing we ever want to imagine is one of our furry friends suffering from cancer. Unfortunately, according to the National Cancer Institute, nearly 6 million cats are diagnosed with cancer each year.1 The good news is that cancer in cats is often treatable, especially when caught early.
Read on to learn about common cancers in cats, symptoms, treatment, treatment costs, and how pet insurance can help.
Most Common Cancers in Cats
Just like in humans, there are many forms of cancer that can affect cats. Here are some of the most common cancers found in felines.
Lymphoma is related to the feline leukemia virus (FeLV), and it involves immune system cells that travel throughout a cat’s body in blood and lymphatic vessels. Lymphoma commonly affects the intestines, so symptoms can be similar to intestinal diseases. However, it can also affect the chest and kidneys.
Typically, you don’t see tumors when it comes to lymphoma, so diagnosing this cancer requires examining cells under a microscope. Lymphoma is usually treated with chemotherapy, but it’s considered incurable, with cats usually going into remission for 2 months to 3 years at a time.2
Squamous cell carcinoma
Squamous cell carcinoma (SCC) is a variety of skin cancer that typically affects a cat’s nose, ears, nail beds, or corners of the eye. Most of the time, there’ll be one lesion found in an affected area. However, multicentric SCC — where multiple lesions are present in multiple locations — is possible. Tumors may show up as ulcers, a raised red area, or a cauliflower-like growth.
Even with multicentric SCC, this cancer typically doesn’t spread, but it can happen. Treatment for SCC usually entails surgical removal of skin tumors. However, if a cat’s nose is affected, radiation therapy may be involved.3
Mammary tumors affect a cat’s mammary glands and are caused by abnormal replication of the cat’s breast tissue. They’re usually seen in middle-aged to senior cats. Typically, the formation of these tumors is related to a cat’s hormone status, with female cats that haven’t been spayed being seven times more likely to develop mammary tumors than those that are spayed. Usually, you’ll be able to see or feel a lump under the skin near a nipple.
Treatment for mammary carcinoma often requires surgery to remove the breast tissue, followed by chemotherapy to prevent the cancer from spreading. Larger tumors, multiple tumors, and cancer that’s spread to blood vessels have a less desirable prognosis — so early detection and action is important.4
Basal cell tumor
Basal cell tumors are abnormal growths due to the uncontrolled replication of basal cells in hair follicles, sweat glands, or sebaceous (oil) glands. Basal cells are various types of cells that make up the outermost skin layer. Basal cell tumors may show up as firm, hairless, raised bumps on the skin — usually around the neck, head, and shoulders. Most of these tumors are benign (noncancerous) and don’t spread, but sometimes they’re cancerous.
Treatment typically involves surgically removing the mass, and prognosis tends to be good following removal.5
Mast cell tumor
Mast cell tumors are tumors made up of mast cells that may be found on the skin or internal organs, typically the spleen and intestines. Mast cells are a type of white blood cell in the outermost skin layer. Mast cell tumors usually show up as hard, flattened areas or small lumps in the skin around the head and neck. But if the spleen or intestines are affected, you likely won’t see a bump, and signs similar to intestinal diseases may be present.
This type of cancer may spread if the spleen and intestines are affected. Treatment usually involves surgical removal of the tumors with potential chemotherapy or radiation therapy.6
Osteosarcoma is a form of bone cancer — commonly affecting the leg bones — caused by abnormal production of bone cells. However, osteosarcoma can also affect tissues, like those of the spleen, kidneys, mammary glands, and liver. Unfortunately, this cancer can be very painful for cats. Swelling, pain or warmth to the touch, lethargy, and lameness of an affected limb may be signs of osteosarcoma.
Since osteosarcoma commonly affects the legs, amputation of the affected limb is a common treatment protocol. Spreading of this cancer is rare, so amputation tends to control the disease, and chemotherapy typically isn’t needed.7