Understanding Liver Cancer and the Role of SIRT in Treatment

By Samuel J. Greene, MD

The American Cancer Society estimates that over 41,000 new cases of liver cancer will be diagnosed in the United States this year.

What’s more, the Society reports that nearly 30,000 people will die of the disease in 2024.

Fortunately, at Penn Medicine Princeton Cancer Center, patients have access to several innovative treatment options, including selective internal radiation therapy (SIRT), that can help slow the progression of liver cancer, manage symptoms and improve quality of life.

October is Liver Cancer Awareness Month, a time to raise awareness about this often-overlooked disease.

About Liver Cancer

Located behind the lower ribs, the liver is one of the largest organs in the body. It performs many important functions, including removing toxins from the blood and aiding digestion.

Liver cancer happens when abnormal cells grow out of control inside the liver and is classified into two main types: primary and secondary.

Primary liver cancer arises from cells inside the liver. Risk factors for primary liver cancer include:

• Chronic (long-term) hepatitis B or C infection
• Cirrhosis (severe liver damage that leads to scarring inside the liver)
• Excessive alcohol consumption
• Obesity
• Fatty liver disease
• Smoking

Secondary liver cancer is cancer that spreads (metastasizes) to the liver after developing in another part of your body. In the United States, secondary liver cancer is much more common than primary liver cancer.

Colorectal cancer is one of the most common cancers to spread to the liver. In addition to colorectal cancer, metastatic liver cancer is most often associated with breast, lung, esophageal, stomach, pancreatic, kidney and melanoma skin cancers.

Symptoms

In its early stages, liver cancer may not cause any symptoms. As the disease progresses, symptoms may include:

• Unexplained weight loss
• Abdominal pain or swelling
• Fatigue
• Yellowing of the skin and eyes (jaundice)
• Itchy skin
• Fever

If you experience symptoms of liver cancer or are concerned about your risk for the disease, see your physician promptly.  Additionally, if you are at high risk for liver cancer, talk with your doctor about screening.

Treatment Options

Treatment for liver cancer varies depending on the stage of the disease, liver function and overall health of the patient. Options typically include:

• Surgery. Removing part of the liver (resection) or undergoing a liver transplant.

• Ablation. Ablation uses thermal energy — either very, very hot or very, very cold — to burn or freeze the tumors and kill the cancer cells.

• Chemotherapy and targeted therapy. These drugs aim to slow the growth of cancer cells or target specific molecules involved in tumor growth.

• Radiation therapy. High-energy rays or particles are used to destroy cancer cells. This is where selective internal radiation therapy (SIRT) comes into play.

How SIRT Works

Selective internal radiation therapy, also known as radioembolization, is a form of targeted radiation therapy specifically for liver cancer. It is often used when surgery isn’t an option due to the size or location of the tumor, or if cancer has spread to other areas.

SIRT is a two-step process that delivers radiation directly to liver tumors by injecting tiny beads — also called microspheres — containing radioactive isotopes into the artery that provides the liver’s blood supply. Here’s how it works:

During the first visit, radiologists use imaging to chart the liver’s blood supply and then inject a contrast dye to help them identify and block blood vessels to the gut to protect it from the radiation.

A small dose of radiation is delivered to ensure it is being delivered precisely to the tumors.

The procedure is performed through a catheter in the femoral artery near the groin.

During the second visit, radiologists again use a catheter in the femoral artery to  access the liver and then deliver the radioactive microspheres.

The microspheres lodge in the small blood vessels of the tumor, releasing high doses of radiation directly to the cancerous tissues while sparing healthy liver tissue. Over time, the radiation damages the cancer cells and causes them to die off.

The entire procedure takes about 90 minutes and patients are usually under general anesthesia.  Most patients return home the same day of the procedure.

Benefits of SIRT

There are many benefits of SIRT, including:

• Precision. Because the radiation is delivered directly to the tumor, healthy tissues experience less damage.

• Minimally invasive. SIRT is performed via a catheter inserted into the bloodstream, making it a less invasive alternative to surgery.

• Fewer side effects. SIRT is often better tolerated than traditional treatments, with fewer side effects.

• Prolongs survival. Studies have shown that for certain liver cancer patients, particularly those with advanced cancer or who cannot undergo surgery, SIRT can improve survival and quality of life.

SIRT is generally well-tolerated. Side effects are mild and may include flu-like symptoms such as fatigue and nausea that normally resolve within a week.

Protect Your Liver Health

While there is no guaranteed way to prevent liver cancer, there are certain steps you can take to protect your liver health and reduce your risk, including:

• Reducing your risk for hepatitis B and C. Both hepatitis B and C spread from person-to-person through unprotected sex, sharing needles and childbirth. To reduce your risk, practice safe sex and avoid sharing needles.

• Getting vaccinated for hepatitis B. The U.S. Centers for Disease Control and Prevention (CDC) recommends that all children and adults up to age 59, as well as older adults at risk for hepatitis B, get the hepatitis B vaccine. There is no vaccine for hepatitis C.

• Getting screened for hepatitis B and C. Because you can be infected with hepatitis B and C and may not know it, the CDC recommends that you get screened at least once in your lifetime and more often if you are at higher risk. If you are diagnosed with hepatitis B or C, medications can help treat the disease and reduce the risk for liver cancer.

• Limiting alcohol and tobacco use. Excessive alcohol use can lead to cirrhosis, which in turn can cause liver cancer. Smoking also increases the risk for liver cancer. In addition, both alcohol and tobacco use can lead to other cancers that can spread to the liver.

• Maintaining a healthy weight. Obesity is associated with fatty liver disease and diabetes, both linked to liver cancer.

• Getting screened for other primary cancers. Talk with your doctor about routine screening for colorectal and breast cancers as well as screening recommendations for lung and other cancers.

• Visiting your regular health care provider for an annual checkup and to discuss your cancer risk.

To find a physician with Penn Medicine Princeton Health, call (888) 742-7496 or visit www.princetonhcs.org. 

Samuel J. Greene, MD, specializes in diagnostic and vascular and interventional radiology. He is a member of the medical staff at Penn Medicine Princeton Health.