Treatment Options for Canine Hepatocellular Carcinoma

Treatment approaches for canine hepatocellular carcinoma (HCC) can vary depending on several factors, including the tumor subtype, the size and location of the tumor within the liver, whether the tumor can be surgically removed, and the overall health of the dog.

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.}

Because these tumor subtypes can affect how widely the tumor is distributed within the liver, they may influence both prognosis and the treatment approaches that veterinary teams may consider.

In many cases, treatment planning begins with determining whether the tumor is resectable (able to be surgically removed) or unresectable, as this distinction often plays an important role in determining which management options may be considered.

Primary care veterinarians and veterinary oncologists evaluate diagnostic findings and case-specific factors when determining appropriate management strategies for each individual patient.

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 one of the most commonly considered treatment approaches for dogs with hepatocellular carcinoma when the tumor is localized (confined to one area of the liver) and surgically accessible.

The liver is composed of several lobes, and in some cases a tumor may be confined primarily to a single lobe, which is commonly seen in massive HCC. In this case, a veterinary surgeon may determine that removal of the affected portion of the liver is feasible.

Several retrospective studies evaluating dogs undergoing surgery for HCC have reported favorable long-term outcomes in dogs with resectable tumors. 

In one study examining dogs with massive HCC, the surgically treated group had a median survival time exceeding 1,460 days, with no local recurrence reported and a low rate of metastasis.^{Liptak et al.}

Tumor location within the liver may be associated with differences in surgical risk during liver tumor removal. In the previously mentioned study of dogs undergoing surgical removal of massive hepatocellular carcinoma, intraoperative mortality was higher when right-sided tumors were resected, likely because of their close association with major vascular structures such as the caudal vena cava.^{Liptak et al.}

Systemic Therapies

When tumors cannot be surgically removed, veterinary oncologists may consider systemic therapies. These treatments may include chemotherapy or targeted therapies.

Compared with surgical management, however, published evidence evaluating systemic therapies for canine HCC remains relatively limited.

Chemotherapy

Chemotherapy involves medications designed to target rapidly dividing cancer cells and is commonly used in the treatment of many types of cancer in dogs.

However, published clinical evidence evaluating chemotherapy for canine HCC remains limited, and chemotherapy is typically not considered a primary treatment option when tumors are surgically resectable.

In some cases involving advanced or unresectable disease, veterinary oncologists may consider metronomic chemotherapy, which involves the continuous administration of low doses of chemotherapy drugs with the goal of slowing tumor progression.

Targeted Therapies

Targeted therapies are medications designed to interfere with molecular pathways involved in tumor growth or angiogenesis (the formation of new blood vessels that supply tumors).

Sorafenib

Sorafenib, a multikinase inhibitor used in the treatment of hepatocellular carcinoma in humans, has also been evaluated in dogs with HCC.

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.}

Although these findings are encouraging, 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 mast cell tumors in dogs, has also been considered in the treatment of HCC in dogs. However, published evidence evaluating its effectiveness specifically for canine HCC remains extremely limited and currently includes case-level evidence, such as a report describing adjuvant toceranib use in a dog with mixed hepatocellular carcinoma and cholangiocarcinoma^{Choi et al.}.

Emerging and Investigational Therapies

Researchers continue to explore new treatment approaches for canine HCC. Some emerging therapies aim to target tumors through novel mechanisms or to enhance the body's immune response against cancer cells. While these approaches show promise in certain contexts, many remain under investigation and additional research is needed to better understand their potential role in treating canine HCC.

Immunotherapy

Immunotherapy refers to treatments designed to stimulate or modify the immune system so that it can recognize and attack cancer cells. Some immunotherapy approaches are currently being explored in dogs with cancer, including therapeutic vaccines and other immune-based therapies.

While certain immunotherapy treatments may be available through veterinary oncology specialists, many approaches are still being studied in clinical trials to better understand their potential effectiveness and safety in different types of canine cancer, including HCC.

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 directly into the tumor’s arterial supply before embolization is performed.

The use of these approaches in dogs with liver tumors is still being investigated, and ongoing clinical studies are evaluating whether these procedures may have a role 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

In some cases, treatment may focus on maintaining comfort and quality of life rather than attempting tumor removal or direct tumor control.

Supportive care may include:

• monitoring liver function through blood tests and evaluating tumor progression through imaging
• managing symptoms associated with liver disease
• nutritional support
• medications that support liver function or help manage complications

For some dogs, supportive care may play an important role in maintaining comfort and overall well-being.

Discussing Treatment Options With Your Veterinary Team

Because every case of canine HCC is unique, treatment decisions are typically individualized. Veterinarians and veterinary oncologists consider multiple factors when discussing management options, including tumor location, diagnostic findings, resectability, and the overall health of the dog.

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.