The cancer stage describes how far a cancer has grown and spread at the time of diagnosis. This is based on the size of the cancer and the results of biopsies, scans and other tests.

Knowing the stage of a cancer helps doctors to work out the best treatment options. It also means the person with cancer can fully understand their situation and discuss any concerns they have.

Staging by location

Sarcomas are staged in different ways depending on what part of the body they start in. The group used are:

• arms, legs and trunk (chest, back and abdomen)
• retroperitoneum (area behind the peritoneum)
• head and neck
• organs inside the chest or abdomen.

The stage is generally based on the TNM system and the grade of the cancer. These may also be used to give a stage number to the cancer.

TNM system

The TNM system is often used in cancer staging. It measures three categories:

• T (tumour) – how large the tumour (cancer) is
• N (lymph node) – whether it has spread into any of the surrounding nodes
• M (metastasis) – whether it has spread to other parts of the body.

Cancer grade

The grade of a cancer is based on how abnormal the cells look under a microscope. Cancers with very abnormal cells are likely to grow and spread faster. 

• Grade 1 (low grade) – the cells look similar to normal cells and are growing and dividing slowly.
• Grade 2 (intermediate grade) – the cells don’t look like normal cells and are growing and dividing faster than normal cells.
• Grade 3 (high grade) – the cells look very abnormal and are growing and dividing quickly.