Staging and grading of bone cancer

What is staging and grading?

Your cancer doctor needs information about the cancer to talk about the best treatment for you. This includes:

the grade of the cancer
the stage of the cancer.

This information comes from the tests you have had.

The grading and staging of primary bone cancer is complex. Your cancer doctor and specialist nurse will talk to you about this. They will explain how it helps you and your cancer doctor decide on a treatment plan that is right for you.

We understand that waiting to know the stage and grade of your cancer can be a worrying time. We're here if you need someone to talk to. You can:

Call the Macmillan Support Line on 0808 808 00 00.
Chat to our specialists online.

Grading bone cancer

Doctors look at a sample of the cancer cells under a microscope to find out the grade of the cancer.

The grade gives an idea of how quickly the cancer might grow or develop.

The most common grading system for primary bone cancer uses the following 3 grades:

Grade 1 - cancer cells are low-grade and look like normal bone cells. They are usually slow-growing and less likely to spread.
Grade 2 - cancer cells are high-grade and look abnormal. The cells are likely to grow more quickly and are more likely to spread.
Grade 3 - the cancer cells are high-grade but the cells look more abnormal than grade 2. This means the cancer is more likely to come back (recur) or spread to other parts of the body.

All Ewing sarcoma and most osteosarcoma and spindle cell tumours are high-grade.

Staging bone cancer

The stage of a primary bone cancer describes:

its size
whether it has spread outside the bone where it started.

Knowing the stage of the cancer helps the doctors plan the best treatment for you.

There are different staging systems used for primary bone cancer. The staging systems often include the following terms.

TNM staging

TNM stands for Tumour, Node and Metastases:

T - describes the size of the tumour.
N - describes whether the cancer has spread to lymph nodes.
M - describes whether the cancer has spread to another part of the body, such as the lungs or liver. This is called metastatic or secondary cancer.

TNM staging system

TNM stands for Tumour, Node and Metastases:

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

Enneking staging system

As well as the size of the tumour and if it has spread, the Enneking staging system also describes the grade of the cancer. It helps your surgeon decide how much bone to remove during surgery.

Stage 1

Stage 1 bone cancer is low-grade. It has not spread beyond the bone. Stage 1 is divided into:

Stage 1A - The cancer is completely inside the bone it started in. The cancer may be pressing on the bone wall and causing a swelling, but it has not grown through it.
Stage 1B - The cancer has grown through the bone wall.

Stage 2

Stage 2 bone cancer is high-grade. It has not spread beyond the bone. Stage 2 is divided into:

Stage 2A - The cancer is completely inside the bone it started in.
Stage 2B - The cancer has grown through the bone wall.

Stage 3

Stage 3 bone cancer may be any grade. It has spread to other parts of the body, such as the lungs.

About our information

References

Below is a sample of the sources used in our information about primary bone cancer. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

European Society for Medical Oncology, ESMO. 2021. Bone sarcomas: ESMOeEURACANeGENTURISeERN PaedCan Clinical Practice Guideline for diagnosis, treatment and follow-up. Annals of Oncology. S. J. Strauss1 et al. Available at: https://www.esmo.org/guidelines/guidelines-by-topic/sarcoma-and-gist/bone-sarcomas (accessed July 2023)

UK guidelines for the management of bone sarcomas, Clinical Sarcoma Research (2016) 6:7. Gerrand C et al on behalf of the British Sarcoma Group. Available at: UK guidelines for the management of bone sarcomas - PMC (nih.gov)(accessed July 2023)

British Medical Journal, BMJ Best Practice. Osteosarcoma. Last updated May 2022. Last reviewed 27 Jun 2023. Available at: Osteosarcoma - Symptoms, diagnosis and treatment | BMJ Best Practice (accessed July 2023)

Reviewers

This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by senior medical editor Fiona Cowie, Consultant Clinical Oncologist.

Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

use plain English
explain medical words
use short sentences
use illustrations to explain text
structure the information clearly
make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.