What is liver metastasis?
A liver metastasis is a cancerous tumor that has spread to the liver from a cancer that started in another place in the body. It’s also called secondary liver cancer. Primary liver cancer originates in the liver and most commonly affects individuals who have risk factors such as hepatitis or cirrhosis.
Most of the time, cancer in the liver is secondary, or metastatic.
The cancer cells found in a metastatic liver tumor are not liver cells. They are the cells from the part of the body where the primary cancer began (for example, cancerous breast, colon, or lung cells).
Other names for this condition include:
- liver metastases
- metastases to the liver
- stage IV or advanced cancer
To understand liver metastasis, it’s important to understand the role of the liver in your body. The liver is the largest organ inside the body, and it’s vital to life. The liver divided into two lobes and is located under the right ribcage and lung.
The liver’s jobs include:
- cleansing the blood of toxins
- making bile, which helps in digesting fat
- making many types of proteins used throughout the body for fuel and cell regeneration
- making enzymes that initiate and participate in numerous body metabolic functions
- storing glycogen (sugar), which the body uses for energy
The liver is one of the most important organs in the body. It’s impossible to live without a functioning liver.
There may be no symptoms in the early stages of liver metastasis. In later stages, cancer can cause the liver to swell or obstruct the normal flow of blood and bile. When this happens, the following symptoms may occur:
- loss of appetite
- weight loss
- dark-colored urine
- abdominal swelling or bloating
- jaundice, a yellowing of the skin or the whites of the eyes
- pain in the right shoulder
- pain in the upper right abdomen
- sweats and fever
- enlarged liver
When the liver is enlarged, a lump can be felt on the right side of the abdomen below the ribcage.
It’s important to see your doctor right away if you have any of the symptoms described above. The following symptoms indicate a more urgent and serious problem:
- persistent vomiting, meaning vomiting more than twice a day for more than one day
- blood in vomit
- recent, unexplained weight loss
- black bowel movements
- difficulty swallowing
- new swelling in the legs or abdomen
- jaundice or yellowing of skin
You should see your doctor immediately if you develop symptoms of liver metastasis. If you’ve ever had any type of cancer, you should be seeing your doctor regularly for checkups.
The risk that cancer will spread, or metastasize, to the liver depends on the location of the original cancer. Primary cancers that are most likely to spread to the liver are cancers of the:
Even if the primary cancer is removed, liver metastasis can still occur years later. If you’ve had cancer, it’s important to learn the signs of liver metastasis and get regular checkups.
There are six steps in the metastasis process. Not all cancers follow this process, but most do.
- Local invasion: Cancer cells move from the primary site into nearby normal tissue.
- Intravasation: Cancer cells move through the walls of nearby lymph vessels and blood vessels.
- Circulation: Cancer cells migrate through the lymphatic system and the bloodstream to other parts of the body.
- Arrest and extravasation: Cancer cells stop moving when they reach a distant location. They then move through the capillary (small blood vessel) walls and invade nearby tissue.
- Proliferation: Cancer cells grow at the distant location and create small tumors called micrometastases.
- Angiogenesis: Micrometastases stimulate the creation of new blood vessels, which supply the nutrients and oxygen needed for tumor growth.
The doctor may suspect liver cancer if the liver is enlarged on examination, if the liver surface is not smooth, or if any of the symptoms above are reported. Various kinds of testing will be needed to confirm the diagnosis. These tests include:
Liver function tests
Liver function tests are blood tests that indicate how well the liver is functioning. Liver enzyme levels are often elevated when there is a problem. Blood or serum markers are substances in the blood that are linked to cancer. When primary liver cancer is present, there may be higher levels of alpha-fetoprotein (AFP) detected in the blood. Liver function tests can help distinguish between primary liver cancer and liver metastasis. AFP markers can also be used to monitor treatment effects of primary liver cancer.
CT scan of the abdomen
A computed tomography (CT) scan is a special kind of X-ray that takes visual images of soft-tissue organs in detail. Cancerous tissue will have a moth-eaten appearance.
Ultrasound of the liver
Also called sonography, an ultrasound transmits high-frequency sound waves through the body. These sound waves produce echoes. The echoes are then used to create map-like computerized images of the body’s soft-tissue structures.
Magnetic resonance imaging (MRI) creates extremely clear images of internal organs and soft-tissue structures. It uses radio waves, a large magnet, and a computer.
In an angiogram, dye is injected into an artery. When images are taken of the body along that artery’s pathway, it can produce high-contrast images of internal structures.
The laparoscopy is a narrow tube with a light and a biopsy (tissue sample) tool. The laparoscope is inserted through a small incision, and biopsies are taken for study under a microscope. Laparoscopy is the most reliable minimally invasive method of diagnosing cancer.
If your cancer has spread to the liver, it’s mostly likely stage IV. Staging assigns a number — 1 through 4) — to the cancer. Staging ranges from a localized tumor (1) to systemic metastases (spreading of cancer) to the bloodstream, lymphatic system, and other organs (2 through 4).
Several options are currently used for treating cancer that has metastasized to the liver. In most cases treatment will be palliative. This means that it will be used to control symptoms of the cancer and prolong life but will not likely result in cure. Generally, the choice of treatments will depend on:
- the person’s age and overall health
- the size, location, and number of metastatic tumors
- location and type of the primary cancer
- the types of cancer treatment the patient had in the past
Systemic cancer therapies treat the whole body through the bloodstream. These therapies include:
Chemotherapy is a form of treatment that uses drugs to kill cancer cells. It targets cells that grow and multiply quickly, including some healthy cells.
Biological response modifier (BRM) therapy
BRM therapy is a treatment that uses antibodies, growth factors, and vaccines to boost or restore the immune system. This helps your immune system’s ability to fight cancer. BRM therapy does not have the usual side effects of other cancer therapies and, in most cases, is well tolerated.
Targeted therapy also kills cancer cells, but it’s more precise. Unlike chemotherapy drugs, targeted treatments can differentiate between cancer and healthy cells. These drugs can kill cancer cells and leave healthy cells intact. Targeted therapies have different side effects than some other cancer treatments. Side effects, which can be severe, include fatigue and diarrhea.
Hormonal therapy can slow or stop the growth of certain types of tumors that rely on hormones to grow, such as breast and prostate cancer.
Localized therapies target only tumor cells and nearby tissue. They can be used when the liver tumors are small in size and number.
This therapy uses high-energy radiation to kill cancer cells and shrink tumors. It may come from:
- radiation machines, such as external beam radiation
- radioactive materials placed in the body near cancer cells, known as internal radiation
- radioactive substances that travel through the bloodstream
Radiofrequency ablation (RFA)
RFA is commonly used to treat primary liver cancer and can be used to treat liver metastasis. RFA is a procedure that uses high-frequency electrical currents to create heat that destroys the cancer cells.
Surgical removal is possible when there are a small number of tumors that affect only a small area of the liver.
In nearly all cases, once a primary cancer has spread or metastasized to the liver there is no cure. However, current treatments can help to improve life expectancy and relieve symptoms.
The relative success of treatment depends on the location of the primary cancer and how much of it has spread to the liver.
Current research is looking for new ways to fight and kill cancer cells, such as hyperstimulating the immune response and disrupting individual steps in the metastatic process.