The life expectancy of hepatocellular carcinoma in dogs tends to vary based on several factors. Things to keep into consideration include the form in which the condition presents, its location, how advanced the cancer is, the health and age of the dog, treatments pursued and whether the cancer has spread to other organs. If your dog was diagnosed with this form of liver cancer, you may want to know what to expect and may be interested in learning more about the prognosis associated with this condition. Some answers on the life expectancy of hepatocellular carcinoma in dogs can be obtained by looking at some studies.
Hepatocellular Carcinoma in Dogs
Hepatocellular carcinomas are the most common types of malignant cancers affecting the dog's liver. Male dogs appear to be more predisposed. Most affected dogs are between 11 or 12 years of age, with more than 80 percent being 10 years or older.
There are several forms of this liver cancer. The mass on the liver may appear as massive, nodular or diffuse.
The most common form (over 50 percent) is the massive form which is characterized by a large mass affecting a single lobe (a dog's liver is made up of six separate lobes). In general, the left liver lobes have a tendency of being more affected by massive hepatocellular carcinomas.
The nodular form of this cancer accounts for 16 to 29 percent of all canine hepatocellular carcinoma cases. This form tends to display several nodules of various sizes scattered within several lobes. The diffuse form instead accounts for only 10 percent of cases and is characterized by large areas of the liver infiltrated with nonencapsulated neoplastic tissue.
Hepatocellular carcinomas are metastatic cancers which means that they tend to spread to other organs. In particular, this cancer tends to spread to the lymph nodes of the liver, the lungs and the peritoneum.
The various forms of this cancer have a different rate of metastasis at the time of diagnosis. The diffuse form tends to spread 100 percent, the nodular form 93 percent and the massive form is often found to have spread 36 percent at the time of diagnosis.
Dogs affected by this form of cancer tend to exhibit vague symptoms such as loss of appetite, weight loss, vomiting and increased drinking. Advanced cases may sometimes trigger nervous system disorders and seizures due to low glucose levels or the accumulation of waste products in the bloodstream meant to be filtered by the liver (hepatic encephalopathy in dogs).
Did you know? According to a study conducted by Hammer, Sikkema in 1995, only 26 percent of all liver masses were primary liver tumors. The majority of masses found on a dog's liver are therefore likely to occur secondary to cancers occurring in other locations. In other words, they have spread to the liver from a primary site.
Life Expectancy of Hepatocellular Carcinoma in Dogs
Poor responses to systemic chemotherapy and radiation, have made these two option unpopular with this form of cancer. Surgical intervention remains the gold standard treatment. It has been demonstrated that up to 75 percent of the liver can be surgically removed without any significant consequences. This happens courtesy of the liver's ability to regenerate which happens fairly quickly (generally within 6 to 8 weeks).
According to a study, dogs who underwent surgery for removal of a massive hepatocellular carcinoma had significantly higher survival times compared to dogs who were managed conservatively without surgery. In the study, 42 dogs were treated surgically while 6 were managed conservatively.
Seventy-one percent of the dogs treated surgically showed clinical signs such as weight loss, inappetence, and lethargy with a median duration of 68 days. Forty-five percent of the dogs were found to have an abdominal mass and anemia was detected in 54 percent of the 41 dogs that were evaluated.
In dogs who underwent surgery, the median survival time was over 1,460 days. Dogs that showed high elevated levels of alanine aminotransferase and aspartate aminotransferase in their blood work and right-sided tumors had a poorer prognosis. In dogs treated conservatively, without going through surgery, median survival times were 270 days.
Interestingly, the location of the mass played a role in the prognosis of dogs treated surgically. This is likely due to the proximity to vasculature and the difficulty of the surgery. Generally, dogs with masses removed from the the left liver lobe had median survival times of 1,460 days, masses removed from the central lobes had median survival times of 795 days, while dogs with masses removed from the right lobes had median survival times of 365 days.
Regardless, due to the higher mortality rate in dogs not treated surgically (left untreated these tumors either metastasize or, more commonly, rupture), surgical intervention remains the standard procedure considering the higher life expectancy and the excellent tumor control ( generally no local recurrence and low metastatic rate).
Did you know? Chemoembolization for inoperable hepatocellular carcinomas is being studied for use in dogs. Consult with a veterinary oncologist for options.
For further reading:
- Dog liver cancer biopsy procedure and costs
- Causes of enlarged liver in dogs
- How steroids affect the dog's liver
- Dog cancer spread to the liver
- Life expectancy in dogs with liver cancer
- Drugs toxic to dog's liver
- Trigo FJ, Thompson H, Breeze RG, et al. The pathology of liver tumours in the dog. J Comp Pathol 1982;92:21-39.
- Hammer AS, Sikkema DA. Hepatic neoplasia in the dog and cat. Vet Clin North Am Small Anim Pract 1995;25:419-435.
- Liptak JM, Dernell WS, Monnet E, et al. Massive hepatocellular carcinoma in dogs: 48 cases (1992-2002). J Am Vet Med Assoc 2004;225:1225-1230.
- Veterinary Partner: Liver Tumors and Cancers