The stage of the cancer describes its position and whether it has spread from where it started. Knowing the stage helps doctors decide on the best treatment for you.
Your cancer doctor can use the results of your tests to try to identify the stage of the cancer. They will do this before surgery, or if you cannot have surgery. But they may not know the exact stage of the cancer until it has been removed with surgery.
- TNM staging system
- number staging system.
The TNM staging system is the one most commonly used for oesophageal cancer.
TNM staging system
TNM stands for tumour, nodes and metastasis. It can help to look at the information about the oesophagus when you read this to understand the staging.
- T describes how far the tumour has grown into the oesophageal wall.
- N describes whether the cancer has spread to the lymph nodes.
- M describes whether the cancer has spread to other parts of the body (metastases).
- T1 means the tumour has grown into the inner wall (mucosa or submucosa) of the oesophagus:
- T1a – the tumour has grown into the mucosa.
- T1b – the tumour has grown into the submucosa.
- T2 means the tumour has grown into the muscle layer (muscularis) of the oesophagus.
- T3 means the tumour has grown into the outer lining (adventitia) of the oesophagus.
- T4 means the tumour has grown through the outer lining of the oesophagus and into nearby structures, such as the diaphragm or a blood vessel. Doctors sometimes put the letter ‘a’ or ‘b’ after this. This gives extra detail about where the tumour is.
- N0 means there are no cancer cells in any nearby lymph nodes.
- N1 means there are cancer cells in 1 to 2 nearby lymph nodes.
- N2 means there are cancer cells in 3 to 6 nearby lymph nodes.
- N3 means there are cancer cells in 7 or more nearby lymph nodes.
- M0 means the cancer has not spread to other parts of the body.
- M1 means the cancer has spread to other parts of the body, such as the lungs or liver.
Number staging system
Another system used to describe the stage of the cancer is the number staging system. It uses the numbers 1 to 4.
Your cancer doctor can explain number staging to you and how the number stage relates to the TNM stage. There are different number staging systems, depending on if the cancer is staged before or after surgery.
Grading is about how the cancer cells look under the microscope compared with normal cells. The grade of the cancer gives the doctors an idea of how quickly it may develop.
- Grade 1 (also called low grade or well differentiated) means the cancer cells look similar to normal cells, usually grow slowly and are less likely to spread.
- Grade 2 (also called moderate or intermediate grade) means the cancer cells look more abnormal and grow slightly faster.
- Grade 3 (also called high grade or poorly differentiated) means the cancer cells look very different from normal cells, may grow more quickly and are more likely to spread.