How immunotherapy treats hepatocellular carcinoma

Located in the upper right part of the abdomen, above the stomach and small intestine, the liver is linked to the functioning of nearly every major organ system in the body. It filters harmful substances from the blood. It produces bile that the body needs to digest food. It metabolizes macronutrients (proteins, carbohydrates, fats). It stores vitamins and iron. It produces blood clotting factors. These are a few examples, and there are hundreds more.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer, accounting for approximately 90 percent of cancers that begin in the liver. The majority of cases of HCC occur in people with cirrhosis, permanent scarring of the liver that’s often associated with conditions like hepatitis B or C infections, alcohol-related liver disease, or fatty liver disease.

What is the treatment for HCC?

Treatment for HCC will depend on whether the cancer can be removed with surgery, as well as factors like cirrhosis, liver function, if the cancer has spread, the overall health of the person being treated, and numerous other considerations.

Treatment can involve local therapies, or therapies directed at specific tumors. These include surgery to remove tumors, ablation (procedures to destroy tumors), embolization (procedures that block or reduce blood flow to tumors), radiation therapy, and chemotherapy infused into the liver.

Treatment can also involve systemic therapies, drugs that act on cancer cells throughout the whole body. These include chemotherapy, targeted therapy, and immunotherapy.

When is immunotherapy used to treat HCC?

In cancer treatment, immunotherapies are drugs that help the immune system identify and destroy cancer cells. Immunotherapies have become an important treatment option for many people with HCC. Immunotherapy is typically used for cancers that cannot be removed with surgery and/or advanced cancers that have spread beyond the liver.

What immunotherapies are used to treat HCC?

The main immunotherapies used in the treatment of HCC are drugs called immune checkpoint inhibitors.

An immune checkpoint is a protein that prevents the immune system from attacking healthy cells. Immune checkpoints are found on the surface of cells throughout the body. Cancer cells can also produce large numbers of immune checkpoints. This helps cancer cells continue to grow and spread without being attacked by the immune system.

Immune checkpoint inhibitors disable immune checkpoints. This helps the immune system recognize cancer cells for what they are—abnormal cells that need to be eliminated.

Different immune checkpoint inhibitors act on different immune checkpoints. The immune checkpoints that are targeted in the treatment of HCC include:

• PD-1 (programmed death receptor-1)
• PD-L1 (programmed death-ligand 1)
• CTLA-4 (cytotoxic T-lymphocyte-associated protein 4)

How are immune checkpoint inhibitors administered?

Most immune checkpoint inhibitors are administered with intravenous infusions, where a needle is inserted into a vein. This is typically done at an infusion center or a hospital. While infusion schedules vary depending on the specific drug being used, infusions are typically given every 2 to 6 weeks. The number of infusions a person will need will vary.

Certain immune checkpoint inhibitors can be given as subcutaneous injections. A subcutaneous injection is administered with a needle inserted into the subcutaneous layer, a layer of tissue immediately underneath the skin. These injections are typically given in the abdomen or thigh (and specific drugs may only be injected at specific spots on the body). Subcutaneous immunotherapy drugs work the same as their intravenous counterparts, the only difference is the route of administration.

Currently, there are only a limited number of subcutaneous immunotherapy drugs for HCC available, but more are under development. Subcutaneously administered cancer treatments are a topic of interest to medical researchers because this route of administration has the potential to make treatments like immunotherapy more accessible to more people.

Subcutaneous injections take much less time than intravenous infusions and can also be administered at a healthcare provider's office (instead of an infusion center or hospital).

In addition to injections or infusions, a person treating HCC with immunotherapy will need regular checkups to monitor their response to treatment. Checkups are also important for identifying any side effects from treatment and monitoring liver function.

It's important to remember that there is no best treatment for HCC, only the treatment that is best for you. For information about your diagnosis and treatment options, your best source of information will always be your healthcare provider.