Your liver is the largest organ in your abdomen (and your body). It weighs about the same as a half-gallon of milk you’d buy at the supermarket. It’s not only big in size, but also in importance—the liver performs essential functions, like removing waste and filtering out toxins (including medications and alcohol) from the blood. It also secretes bile and enzymes that allow the body to digest food and extract its nutrients, among other things.
Liver cancers are the 6th most common cancer type worldwide. Here in the United States, more than 40,000 liver cancer cases are diagnosed each year. People at the highest risk for liver cancer are those with viral infections of the liver (such as hepatitis) and chronic liver disease (cirrhosis). Fatty liver disease and alcohol-induced liver cirrhosis are other potential causes.
“It’s important to know that most liver diseases, which can lead to liver cancer, are treatable,” says Yale Medicine’s Mario Strazzabosco, MD, director of the Liver Cancer Program at Yale Cancer Center. “Also, many cases of hepatocellular carcinoma (HCC), the most common type of primary liver cancer, can be diagnosed early if high-risk patients are closely monitored by their doctor. There is a lot that we can do for patients diagnosed at an early stage, and some patients can be cured.”
What is liver cancer?
Cancer, in general, occurs at the cellular level. In a healthy body, new cells are generated to replace old, dying ones. But when there’s a disruption—new cells form unnecessarily or old cells don’t die as they should—a collection of extra cells can form a tumor, or growth, that is either benign (not cancerous) or malignant (cancerous). To better understand and properly treat liver cancer, doctors will need to know whether the cancer is primary (started in the liver) or secondary (metastatic, meaning it is cancer that has spread from elsewhere in the body).
Primary Liver Cancer
Cancer that originates in the liver is called primary liver cancer. This includes any malignant growth of liver cells that can eventually spread (or metastasize) to other sites of the body. The most common type of primary liver cancer is called HCC, which is derived from hepatocytes (liver cells), most likely as a result of cirrhosis-related hepatitis B or C virus infections, steatohepatitis and alcoholic liver disease. HCC accounts for 90 percent of all primary liver cancer cases.
Other types of primary liver cancer include:
- Fibrolamellar carcinoma: a variant of HCC with fibrous layers between tumor cells
- Angiosarcoma: a cancer of the blood or lymph vessels in the liver
- Hepatoblastoma: a rare type of childhood liver cancer
- Cholangiocarcinoma: bile duct cancer
Secondary Liver Cancer
Secondary liver cancer (or liver metastasis) is a cancer that has spread to the liver from somewhere else in the body, such as the colon, breast or lung. When this occurs, the new growth contains the same type of cancer cells as the primary tumor. So, if colon cancer spreads to the liver, the liver tumor will contain colon cancer cells, not liver cancer cells. Secondary liver cancer occurs more frequently than primary liver cancer.
Who is at risk for primary liver cancer?
While family history and genetics can be important in predicting a person’s risk of liver cancer, lifestyle can play a role. The following factors can increase your risk of developing liver cancer:
- Cirrhosis: This condition, which involves the deterioration of the liver to the point where it no longer functions properly, is the end-result of most cases of chronic liver damage. Up to 90% of cases of HCC in Western countries can be attributed to patients with liver cirrhosis.
- Chronic viral infections: Studies estimate that over 50% of liver cancers worldwide are caused by hepatitis B or C virus infections.
- Obesity, diabetes, metabolic syndrome: These conditions may promote the development of liver cancer and they account for a growing number of cases.
- Alcoholic liver disease: This condition, involving the overconsumption of alcohol over a long period of time, is an important and preventable cause of liver cancer.
What are the symptoms of liver cancer?
Although patients usually do not have symptoms until the cancer has reached an advanced stage, symptoms of both primary and secondary liver cancers include a combination the following:
- Weight loss
- Loss of appetite
- Yellowing of skin (jaundice)
- Swollen abdomen, due to liver enlargement or ascites (fluid buildup)
How is primary liver cancer diagnosed?
Your doctor can test for liver cancer by performing a physical exam to check for jaundice, or by feeling your abdomen to detect changes in the size and shape of the liver or any nearby organs. Tests for the presence of alpha-fetoprotein, typically only present in pregnant women and in certain cancers, may also be done. Magnetic resonance imaging (MRI), ultrasound, and computed tomography (CT) scans can also be used to identify changes in your liver associated with cancer. Your doctor might extract a small sample of your liver (called a liver biopsy) to confirm a diagnosis.
If your doctor has identified you as an at-risk patient, you start experiencing the symptoms listed above or if you have cirrhosis, he or she may monitor you over time, performing an ultrasound of your liver every six months.
What is liver cancer staging?
It’s important for physicians to know the extent (stage) of the cancer to choose the best treatment option. Early stage liver cancer has not spread, or metastasized, to other parts of the body, and can be identified by a primary liver cancer diagnosis. Advanced stage liver cancer may have spread locally or—via lymph nodes or blood—to other parts of the body. This can be identified using CT or positron emission tomography (PET) scans to determine the presence of liver cancer in the lungs, bones or other parts of the body.
What are the treatments for liver cancer?
Treatment of liver cancer depends on the stage of liver cancer you have. The most effective treatments for early stage liver cancer (where the liver cancer has not spread inside or outside of the liver) include surgery and liver transplantation. Liver surgery (open or minimally invasive) may remove up to 80% of the liver, leaving the remaining healthy liver tissue to take over the functions of the liver and regenerate over time. Liver transplantation removes the liver in its entirety and replaces it with healthy tissue from a donor, that will eventually grow into a fully functional liver. (This is the most effective treatment, but it can only be applied to a small number of patients.)
For patients with advanced stage liver cancer or those not healthy enough to undergo surgery, the following treatment options can extend life and make patients feel better:
- Ablation: This treatment method destroys the cancer by injecting either intense heat or extreme cold directly into the tumor.
- Embolization: This approach physically blocks blood from reaching the liver tumor, starving tumor cells of nutrients and killing them.
- External radiation therapy: This approach kills tumor cells using high energy rays aimed precisely at the tumor site.
- Targeted therapy: This approach attempts to slow tumor growth (or enhance the immune system of the body so it works hard to achieve the same effect). Its side effects are less severe than chemotherapy.
While not a primary treatment option, therapies that boost the immune system (immunotherapies) have had initial success in treating liver cancer in clinical trials and may represent the next generation of liver cancer treatments.
HCC requires a careful selection of treatment options, often in combination or sequentially, notes Dr. Strazzabosco. Therefore, he says, it’s important to be referred to a clinical program specializing in liver cancer that can tailor treatment options specifically to you.
What stands out about Yale Medicine’s approach to liver cancer treatment?
Every liver cancer case is discussed by a multi-specialist team at a weekly meeting (called a tumor board) to ensure each patient receives the best individualized treatment possible, Dr. Strazzabosco says.
“The benefit of the Liver Cancer Program is we are truly a multidisciplinary team, offering personalized care for our patients,” he says. “The program has a number of specialists—hepatologists, medical oncologists, interventional radiologists, surgeons and palliative care doctors—each providing high-level and highly scientific care.”