Staging and grading

After the diagnosis, your cancer specialist will usually want to carry out further tests and investigations to learn more about the cancer. This will include tests to find out the stage and the grade of the cancer, which helps doctors decide on the most appropriate treatment for you.

The stage of a cancer describes its size and whether it has spread beyond its original site. Staging may involve further scans and tests and can take a few days to complete. Your cancer specialist will be able to tell you how long this will be.

The grade of a cancer gives an idea of how quickly it may develop. To find the grade of your cancer, your doctors will look at the cancer cells under a microscope.


Two of the most commonly used staging systems are a numbered staging system and the TNM staging system. The TNM system is more detailed.

TNM stands for Tumour, Node and Metastases.

  • T describes the size of the tumour
  • N describes whether the cancer has spread to the lymph nodes.
  • M describes whether the cancer has spread to another part of the body (known as metastatic or secondary cancer).

Each cancer has its own staging system. Not every cancer uses a number or TNM system. Your doctor can tell you more about the stage of your cancer.


Grading is about how the cancer cells look under the microscope compared with normal cells. Many cancers use the following grading system:

Grade 1 or low-grade or well differentiated

The cancer cells look similar to normal cells and usually grow slowly and are less likely to spread.

Grade 2 or moderate-or intermediate-grade

The cancer cells look more abnormal and are slightly faster growing.

Grade 3 or high-grade or poorly differentiated

The cancer cells look very different from normal cells and may grow more quickly.

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The cancer registry

In the UK, each country has a cancer registry. It is used to plan and improve health and care services.