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Neuroendocrine Cancer Community

Neuroendocrine Cancer Staging and Grading

Apr 13, 2022


Tells us whether the cancer is localised (limited to the area in which it arises) or disseminated (has spread to other places in the body). Staging is usually assessed by scans. Commonly, there are 4 stages: 

  1. Confined to the area in which it starts
  2. Has spread to surrounding cells or tissue
  3. Has spread beyond surrounding tissues and to nearby lymph nodes
  4. Has spread to another place within the body, including lymph nodes.


The rate at which it grows – this is an assessment, using a microscope, to examine cells to see how many are actively replicating and growing. You might see ‘Ki67’ or ‘Mitotic Index’ mentioned in your clinic letters or medical reports alongside a Grading – G1, G2 or G3.

‘Mitotic rate’ (MiB1) or Ki67 are the measurements used to assess the rate at which your cancer is growing.

Ki67 is a protein that is present during all of the active stages of the cell cycle – a useful marker of proliferation (cell division and growth) – often expressed as a percentage (%)

  • Grade 1 is where the Ki67 is less than 3% and cells are ‘well-differentiated’
  • Grade 2 is where the Ki67 is between 3 and 20% and cells are ‘well-differentiated’
  • Grade 3a is where the Ki67 is above 20% and the cells are ‘well-differentiated’
  • Grade 3b is where the Ki67 is above 20% but the cells are ‘poorly-differentiated’.

Grade 3b is treated differently to Grades 1-3a – further information about Neuroendocrine Carcinoma here.

You can find out more here.
Press play to watch this short video where Professor Caplin explains staging and grading in more depth.