Treatment Options for Canine Hepatocellular Carcinoma

Treatment approaches for canine hepatocellular carcinoma (HCC) can vary depending on several factors, including the tumor subtype and the size and location of the tumor within the liver – factors that may affect whether the tumor can be surgically removed – as well as other dog- and disease-specific factors.^{Gibson et al.; Moyer et al.; Nguyen et al.}

Canine HCC is commonly divided into three subtypes: massive, nodular, and diffuse.^{Patnaik et al.}

Tumors classified as the massive subtype typically present as a single large mass within one region of the liver, whereas nodular or diffuse forms may involve multiple areas of the liver.^{Patnaik et al.}

These tumor subtypes may influence both prognosis and treatment approaches, with the distribution of the tumor within the liver affecting whether surgical resection is possible and, in turn, which treatment options may be available.^{Marconato et al.; Moyer et al.} See our page on prognosis and survival in canine hepatocellular carcinoma.

The following sections provide an overview of treatment approaches that may be considered for dogs diagnosed with HCC.

Surgical Resection

Surgical removal of the tumor is a commonly considered treatment approach for dogs with hepatocellular carcinoma when the tumor is localized (confined to one area of the liver) and surgically resectable, as may be the case with massive HCC.^{Gibson et al.; Marconato et al.}

Multiple retrospective studies have evaluated survival outcomes in dogs undergoing surgical resection for HCC.^{Liptak et al.; Matsuyama et al.; Moyer et al.}

Reported median survival times have varied among studies. In studies specifically evaluating dogs with massive HCC, Liptak et al. reported a median survival time exceeding 1,460 days in surgically treated dogs, while Matsuyama et al. reported overall survival of more than 1,836 days in dogs with complete surgical margins and a median overall survival of 765 days in dogs with incomplete margins. In a broader study that included dogs with different HCC subtypes, Moyer et al. reported a median survival time of 695 days in dogs undergoing definitive surgical resection.^{Liptak et al.; Matsuyama et al.; Moyer et al.}

Findings regarding surgical margins have also differed among studies. Matsuyama et al. found significantly longer overall survival in dogs with complete compared with incomplete margins, whereas Moyer et al. found no significant difference in median survival time between dogs with complete and incomplete surgical margins.^{Matsuyama et al.; Moyer et al.}

Tumor location within the liver may also be associated with differences in surgical risk. Liptak et al. reported higher intraoperative mortality in dogs undergoing resection of right-sided massive HCC, while Moyer et al. found that excision of the right medial liver lobe was associated with an increased risk of perioperative death.^{Liptak et al.; Moyer et al.}

Systemic Therapies

Systemic therapies, including chemotherapy and targeted therapies, have been evaluated in dogs with unresectable HCC.^{Marconato et al.}

Chemotherapy

Conventional chemotherapy involves medications designed to target rapidly dividing cancer cells and is commonly used in veterinary cancer treatment.^{AAHA, Chemotherapy}

Metronomic chemotherapy uses low doses of chemotherapy drugs given on an ongoing basis, with the primary focus on helping to keep the disease under control over time.^{AAHA, Chemotherapy}

Published evidence evaluating metronomic chemotherapy in canine HCC is limited. A 2024 review identified a single published study evaluating its therapeutic use in dogs with HCC.^{Petrucci et al.}

In that study of dogs with advanced, unresectable HCC, metronomic chemotherapy was compared with the targeted therapy sorafenib.^{Marconato et al.}

Targeted Therapies

Targeted therapies are treatments that target specific molecules that play a role in cancer cell survival and spread.^{NCI, Targeted Therapy}

Sorafenib

Sorafenib, a multikinase inhibitor used in the treatment of hepatocellular carcinoma in humans, has also been evaluated in dogs with HCC.^{Marconato et al.}

In a prospective study of dogs with hepatocellular carcinoma, sorafenib was associated with a longer time to progression compared with dogs treated with a metronomic chemotherapy protocol. The study also reported that sorafenib was generally well tolerated, although adverse events were observed.^{Marconato et al.}

Additional research is needed to better understand the role sorafenib may play in the treatment of canine HCC.

Toceranib Phosphate (Palladia)

Toceranib phosphate (Palladia), a tyrosine kinase inhibitor approved for the treatment of certain mast cell tumors in dogs, has also been evaluated in dogs with HCC.^{AAHA, Chemotherapy; Heishima et al.}

In one study of dogs with massive HCC that was not amenable to surgery, dogs treated with toceranib had outcomes that included partial response, stable disease, and progressive disease. Mild to moderate adverse effects were reported.^{Heishima et al.}

Toceranib has also been described as adjuvant therapy in a case report involving a dog with mixed hepatocellular carcinoma and cholangiocarcinoma, with mild adverse effects reported.^{Choi et al.}

Further research is needed to better understand the potential role of toceranib in canine HCC.

Emerging and Investigational Therapies

Emerging and investigational therapies are also being explored for canine HCC.

Immunotherapy

Immunotherapy uses the immune system to help recognize and attack cancer cells. Several immunotherapy approaches are being studied in veterinary oncology, including cancer vaccines and other immune-based treatments.^{AAHA, Immunotherapy; Cornell, Immunotherapy Treatment}

Research specifically involving canine HCC remains limited, although an investigational cancer immunotherapy has been evaluated in a pilot safety study that included one dog with HCC.^{Goodrich et al.}

Transarterial Embolization and Chemoembolization

Transarterial embolization (TAE) and transarterial chemoembolization (TACE) are minimally invasive procedures that target tumors through their blood supply. These techniques involve delivering embolic agents into the arteries that supply the tumor in order to reduce blood flow. In TACE, chemotherapy is delivered into the tumor’s arterial supply as part of the embolization procedure.^{Cleveland Clinic, TACE; NCI, TAE}

TACE has been evaluated in dogs, including those with nonresectable hepatocellular neoplasia and nonresectable hepatic carcinoma.^{Culp et al.; Rogatko et al.}

Published evidence remains limited, and additional research is needed to better understand the potential role of TACE in the management of canine liver tumors.

Information about ongoing veterinary studies evaluating emerging therapies can be found on our Clinical Trials page.

Palliative and Supportive Care

Palliative and supportive care can help manage symptoms and maintain comfort and quality of life.^{AAHA, Supportive Care; Cornell, Palliative Treatment}

Depending on a dog's individual needs, supportive and symptomatic care may include the following:^{AAHA, Supportive Care; Cornell, Palliative Treatment}

• pain management
• management of nausea, vomiting, diarrhea, or changes in appetite
• nutritional support
• other measures aimed at managing symptoms or complications associated with the cancer or its treatment

Discussing Treatment Options With Your Veterinary Team

Primary care veterinarians and veterinary oncologists may consider factors such as tumor subtype, location, and resectability, as well as the dog's overall health, when discussing treatment and management options.

If you would like to prepare for these conversations, you may find it helpful to review our guide on Preparing for HCC Appointments, which outlines questions that may be useful to discuss with veterinary professionals.