TNM staging
Staging looks at the size of the cancer (tumour) and whether it has spread anywhere else in the body. There are different staging systems that doctors can use for liver cancer. The TNM staging system is one of these.
TNM stands for Tumour, Node, Metastasis. It describes:
- the size of the primary tumour (T)
- whether the cancer has spread to the lymph nodes (N)
- whether the cancer has spread to another part of the body (M)
The TNM system is used for cancer staging all over the world. It is important for doctors to use the same staging system because then they can be sure they are all talking about the same situation when they are comparing notes or carrying out research.
Tumour (T)
There are 4 main T stages – T1 to T4.
The T stage depends on:
- the size of the tumours
- and whether the cancer has grown into any blood vessels in the liver
If you have surgery to remove your cancer, a sample of liver tissue is then sent to the laboratory. A specialist will look at the cells under a microscope. This might show small (microscopic) growth of cancer cells into the vein or artery.
Scans might also show if your cancer is growing into the blood vessels.
T1 is divided into T1a and T1b:
- T1a means that there is a single tumour in the liver that is 2 cm or less, and it has not grown into blood vessels of the liver
- T1b means that there is a single tumour that is more than 2cm and it has not grown into any blood vessels
T2 means that either:
- there is a single tumour that is more than 2cm and it has grown into blood vessels OR
- there are several tumours in the liver, and they are all less than 5cm
T3 means there are several tumours in the liver, and at least one of them is more than 5cm
T4 means that the cancer has grown:
- into a major branch of one of the main blood vessels (the portal or hepatic veins) OR
- into organs close to the liver (not including the gallbladder) OR
- through the lining that wraps around the internal organs of the abdomen (visceral peritoneum)
Nodes (N)
There are 2 N stages:
- N0 means that there are no cancer cells in nearby lymph nodes
- N1 means that there are cancer cells in lymph nodes near the liver
If there are cancer cells in the lymph nodes, the cancer is advanced and is a stage 4 liver cancer.
Metastasis (M)
There are 2 M stages:
- M0 means there is no sign that the cancer has spread outside the liver
- M1 means there are cancer cells in other parts of the body such as the lungs or bones (advanced cancer)
How the TNM staging system is used
Using the TNM staging system helps your doctor describe very accurately and clearly what stage your cancer is. But day to day, your doctor is likely to describe your cancer as being stage 1, 2, 3, or 4 (the Number staging system). For treatment decisions they are most likely to use the BCLC staging system, which also takes into account how well your liver is working.
Treatment
The stage of your cancer helps your doctor to decide which treatment you need. Treatment also depends on:
- where the cancer is
- how well your liver is working
- other health conditions
You might have surgery if the cancer is only in your liver. This might be surgery to remove part of your liver (liver resection) or a liver transplant.
You might have a local treatment into your liver if you can't have surgery such as:
- heat treatment to destroy the tumour (radiofrequency ablation or microwave ablation)
- chemoembolisation (TACE)
- percutaneous ethanol injection (PEI)
- selective internal radiotherapy (SIRT)
For advanced liver cancer you might have targeted or immunotherapy cancer drugs. For example, drugs such as atezolizumab with bevacizumab or sorafenib. You may have other treatments, such as painkillers or anti sickness drugs, to help with symptoms.
