Liver Tumors and Cancer in Cats

The liver, gallbladder, and bile ducts are collectively referred to as the hepatic system. This system is responsible for the production and secretion of bile, which aids in digestion of fats. The liver also filters toxins from the blood.

Tumors are masses of abnormal cell growth. Cancerous tumors are masses of uncontrolled cell growth which may spread to other parts of the body (metastasize). Primary tumors of the hepatic system grow directly from the hepatic tissue. Metastatic tumors of the hepatic system are tumors which originate from elsewhere in the body and spread to the liver and bile system.

Prognosis is highly dependent on the type of cancer, how widespread it is, and whether it can be surgically removed.

A cat diagnosed with a hepatic tumor is at risk of serious health issues even if the tumor is benign. Malignant tumors have the potential to spread to other areas of the body and are more likely to affect the liver’s ability to function normally.

Cats with feline leukemia virus and feline immunodeficiency virus are more prone to cancer in general.

Benign, primary tumors of the bile ducts (biliary adenomas) are the most common hepatic tumor in cats. Hepatocellular carcinoma is the second most common primary liver tumor in cats and is malignant.

Definitive causes of the different types of hepatic tumors in cats is not known. Genetics and environmental factors may play a role, but specific causes are rarely, if ever, identified. Cats with retroviral infections such as FeLV and FIV are prone to developing cancer.

Massive tumors sometimes cause enlargement of the abdomen and weight gain. Many cats with benign tumors are asymptomatic.

Benign hepatic tumors are often found by chance during x-rays performed for other reasons. Bloodwork and urinalysis results provide more information. An abdominal ultrasound aids in evaluation of the liver and surrounding tissue, which is important in evaluating prognosis.

Biopsy and/or fine-needle aspiration of liver tissue is required to confirm diagnosis.

Treatment may include surgical removal, chemotherapy and/or radiation therapy. A veterinary oncologist referral is often recommended.

Palliative care (hospice) and humane euthanasia are also important to consider when quality of life is low.

Benign hepatic tumors carry an excellent prognosis if surgically removed. Malignant tumors and metastatic disease carry a much poorer prognosis.

There is no known prevention for hepatic tumors and cancers in cats. Hepatic cancers are not contagious, but retroviral infections that can predispose cats to cancers are. Spaying and neutering cats and vaccinating cats against feline leukemia virus can indirectly decrease the risk of certain cancers that may spread to the liver.

Primary hepatic tumors are uncommon in cats.

• Surgical removal
• Chemotherapy
• Radiation therapy
• Palliative care
• Euthanasia