Find out more about how breast cancer size, growth and spread are described.

Staging and grading

Staging and grading are ways in which healthcare professionals describe the size of your breast cancer, whether and how far it has spread, and how fast it may grow (or how ‘aggressive’ it is).

Knowing your cancer’s stage and/or grade helps your breast care team plan the best treatment for you. Staging and grading usually happens after your breast tumour has been removed by surgery, as a pathologist will need to test the tissue in a laboratory and examine it under a microscope.


The grade of a tumour indicates what the cells look like and gives an idea of how quickly the cancer may grow and spread. Tumours are graded between 1 and 3. A higher number indicates that the cells differ more from normal cells and are likely to grow and spread more quickly.

Grading for ductal carcinoma in situ (DCIS) is different, and is defined as low, medium or high grade.


Staging is used to assess the size of a tumour, whether it has spread and how far it has spread. There are two main methods used for defining the stage of a cancer – the TNM (tumour, nodes, metastasis) system and a scale from 0 to 4.

Understanding staging terms

The tumour, nodes, metastases (TNM ) system of staging describes:

  • T: the size of a tumour (a code from 1 to 4)
  • N: the number of lymph nodes affected (X for no nodes, and a code 0–3 when nodes are affected)
  • M: whether and how far the cancer has spread (0 for no spread, 1 for spread).

Another way of defining the stage of a cancer is on a scale from 0 to 4:

  • Stage 0: non-invasive breast cancers, such as DCIS
  • Stage 1 and 2: quite small breast cancers that have spread only to the lymph nodes, if at all
  • Stage 3: breast cancers that are often larger and have spread to the lymph nodes or surrounding tissues
  • Stage 4: breast cancers that have spread to other areas of the body (secondary breast cancers)

More information

More information about staging and grading can be found on the Cancer Research UK website

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Information last reviewed: 21 August 2013

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