Staging and grading of stomach cancer

Knowing the extent of the cancer and the grade helps the doctors decide on the most appropriate treatment|. Doctors often use scans to assess the stage of a cancer – this is called clinical staging. But your doctor may only be able to tell you the exact stage of the cancer after you have had an operation to remove it..

Staging Back to top

TNM staging system

The most commonly used staging system for stomach cancer is called the TNM staging system:

T refers to the size of the tumour.

N refers to whether lymph nodes have cancer in them.

M refers to whether the cancer has spread to other parts of the body (secondary or metastatic cancer).

The T, N and M stages may be grouped together to give an overall stage for the cancer from 1-4.

Number staging system

The stage is often described using a number, which combines information about the tumour, the lymph nodes and whether the cancer has spread. The number stages can be divided further.

You may find it helpful to refer to the diagram below showing the structure of the stomach wall| when reading the following section.

Stage 1 is divided into two stages:

Stage 1A - The cancer is contained within the inner lining of the stomach (mucosa), with no lymph nodes affected.

Stage 1B - Either the cancer is contained within the stomach lining and one or two lymph nodes are affected OR the cancer has grown into the muscle of the stomach wall (muscularis) but no lymph nodes are affected.

Stage 2 is also divided into two stages:

Stage 2A - Either the cancer is within the stomach lining and affects 3-6 lymph nodes OR it has grown into the muscle layer and affects one or two lymph nodes OR it has spread to the outer layer of the stomach (serosa) but no lymph nodes are involved.

Stage 2B - Either the cancer is within the stomach lining and affects seven or more lymph nodes OR it has grown into the muscle layer and affects 3-6 lymph nodes OR it has spread to the outer layer of the stomach and affects one or two lymph nodes OR the cancer has grown outside the stomach wall but there are no cancer cells in nearby lymph nodes.

Stage 3 is divided into three stages.

Stage 3A - Either the cancer has spread into the muscle layer of the stomach and affects seven or more lymph nodes OR it has spread to the outer layer of the stomach and affects 3-6 lymph nodes OR it has grown outside the stomach and affects one or two lymph nodes.

Stage 3B - Either the cancer has spread to the outer layer of the stomach and affects seven or more lymph nodes OR it has grown through the stomach wall and affects 3-6 lymph nodes OR it is through the stomach wall and into nearby tissues and may affect up to two lymph nodes.

Stage 3C - Either the cancer has grown beyond the stomach wall and is found in seven or more lymph nodes OR it has grown beyond the stomach wall and into surrounding tissues and organs and cancer cells are found in nearby lymph nodes.

Stage 4 is advanced stomach cancer, which means that the cancer has spread beyond the stomach to other parts of the body, such as the lungs| or the liver|.

 

 

Grading Back to top

Grading refers to the appearance of the cancer cells under the microscope. The grade gives an idea of how quickly they may develop.

Grade 1 (low-grade) - The cancer cells tend to grow slowly, look quite similar to normal cells (are ‘well differentiated’) and are less likely to spread than higher grades.

Grade 2 (moderate-grade) - The cells look more abnormal and are slightly faster growing.

Grade 3 (high-grade) - The cancer cells tend to grow more quickly, look very abnormal (are ‘poorly differentiated’) and are more likely to spread than low-grade cancer cells.