Your outlook and treatment options for liver cancer depend on a variety of factors, including how far it has spread.
Learn about how liver cancer spreads, the tests used to determine this, and what each stage means.
How does liver cancer spread?
The cells in our bodies have a regulated system of growth and division. New cells are formed to replace older cells as they die. Occasional DNA damage results in abnormal cell production. But our immune system does a pretty good job of keeping them under control. It’s a system that serves us well.
Cancer cells don’t follow these regulations. Part of their abnormality is that they continue to reproduce even though old cells aren’t dying off.
This uncontrolled growth of abnormal cells is what forms a tumor. And because they keep reproducing, they can metastasize (spread) locally and to distant sites.
Liver cancer, like other types of cancer, can spread in three ways.
- Through tissue. Cancer cells break off from the primary tumor in the liver and form new tumors in nearby tissues.
- In the lymph system. Cancer cells make their way into nearby lymph nodes. Once in the lymph system, cancer cells can be transported to other areas of the body.
- Through the circulatory system. Cancer cells get into the bloodstream, which carries them throughout the body. Anywhere along the way, they can establish new tumors and continue to grow and spread.
No matter where your metastatic tumors form, it’s still liver cancer and will be treated as such.
What do the stages of liver cancer mean?
There are no routine screening tests for liver cancer. Because it doesn’t always cause signs or symptoms in the early stages, liver tumors can grow rather large before being discovered.
Liver cancer is staged using the “TNM” system:
- T (tumor) indicates the size of the primary tumor.
- N (nodes) describes lymph node involvement.
- M (metastasis) represents if and how far the cancer has metastasized.
Once these factors are known, your doctor can assign the cancer a stage from 1 to 4, with stage 4 being the most advanced. These stages can give you a general idea of what to expect.
When it comes to treatment, doctors sometimes classify liver cancer based on whether it can be surgically removed:
- Potentially resectable or transplantable. The cancer can be completely removed in surgery, or you’re a good candidate for a liver transplant.
- Unresectable. The cancer hasn’t spread outside the liver, but it can’t be completely removed either. This may be because cancer is found throughout the liver or it’s too close to main arteries, veins, or other important structures such as the bile ducts.
- Inoperable with only local disease. The cancer is small and hasn’t spread, but you’re not a good candidate for liver surgery. This may be because your liver isn’t healthy enough or because you have other health problems that would make surgery too risky.
- Advanced. The cancer has spread beyond the liver into the lymph system or to other organs. It’s inoperable.
Recurrent liver cancer is cancer that has returned after you’ve completed treatment.
What’s the difference between clinical stage and pathologic stage?
Physical examination, imaging tests, blood tests, and biopsy can all be used to stage liver cancer. This stage is called the clinical stage, and it’s helpful in choosing the right kind of treatment.
The pathological stage is more accurate than the clinical stage. It can only be determined after surgery. During the procedure, the surgeon can see if there’s more cancer than could be seen on imaging tests. Nearby lymph nodes can also be checked for cancer cells to provide a more complete picture. The pathologic stage may or may not differ from the clinical stage.
What tests can show if liver cancer is spreading?
Once diagnosed with liver cancer, your doctor will try to determine the stage, which will let you know how advanced it is.
Based on your symptoms and results of a physical examination, your doctor will choose the appropriate imaging tests to detect additional tumors. Some of these are:
- computed tomography scan (CT scan, previously called CAT scans)
- magnetic resonance imaging (MRI scan)
- positron emission tomography (PET scan)
- a biopsy of the tumor, which can help determine how aggressive the cancer is and if it’s likely to spread quickly
If you’ve completed treatment, these tests may be used to check for recurrence.