About staging and grading of soft tissue sarcoma

The information from your biopsy, scans and other test results tells your doctors more about the grade and stage of the soft tissue sarcoma. This information is used by a team of doctors and nurses called a multidisciplinary team (MDT). Your MDT will decide on the most appropriate treatment for you.

Some types of soft tissue sarcoma are staged and graded slightly differently. We have more information about

Grading soft tissue sarcoma

The grade of a cancer gives the doctors an idea of how quickly it might grow. Doctors look at a sample of the cancer cells under a microscope to find the grade of the cancer.

Grading of soft tissue sarcomas can sometimes be difficult. The grade is based on three things:

  • how normal or abnormal the cells look – this is called differentiation
  • how quickly the cells are dividing to make new tumour cells – this is called the mitotic rate
  • if there is any dying tissue in the tumour – this is called necrosis.

There are three grades:

  • G1 – the cancer cells look like normal cells, are usually slow-growing and are less likely to spread.
  • G2 – the cancer cells look different to normal cells and are slightly faster growing.
  • G3 – the cancer cells look very different to normal cells, may grow more quickly, and are more likely to spread.

Staging soft tissue sarcoma

The stage of a cancer describes its size and whether it has spread from where it started. Knowing the stage helps doctors decide on the best treatment for you.

Different staging systems may be used. Two of the most commonly used systems are the TNM and number staging system.

TNM staging

TNM stands for Tumour, Node and Metastasis.

  • 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, such as the liver or lungs (known as metastatic or secondary cancer).

Doctors put numbers after the T, N, and M that give more details about the size and spread of the cancer.

Number staging

Information from the TNM system and the grade of the cancer can be used to give a number stage. The number stages vary slightly depending on where in the body the cancer started.

Soft tissue sarcomas are usually divided into four stages:

  • Stage 1A – The cancer is smaller than 5cm, and either it is low grade or the grade is not known.
  • Stage 1B – The cancer is bigger than 5cm, and either it is low grade or the grade is not known.
  • Stage 2 – The cancer is smaller than 5cm, and it is either moderate or high grade.

Stage 1 and 2 soft tissue sarcomas have not spread to lymph nodes or other parts of the body.

  • Stage 3A – The cancer is bigger than 5cm but not bigger than 10cm. It is either moderate or high grade, and it has not started to spread.
  • Stage 3B – Can be either of the following:
    • The cancer is bigger than 10cm. It is either moderate or high grade, and it has not started to spread.
    • Or the cancer is of any size and grade, and it has spread to at least one lymph node. It has not spread to any other parts of the body.
  • Stage 4 – The cancer is of any size and grade. It may or may not have spread to lymph nodes. But it has spread to another part of the body such as the lungs, liver or bones. This is called secondary or metastatic cancer.

Your doctor or specialist nurse can give you information about the grade and stage of the sarcoma.