Sarcomas, Soft Tissue: Stages and Grades

Approved by the Cancer.Net Editorial Board, 11/2020

ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread, and how quickly it may grow. This is called the stage and grade. Use the menu to see other pages.

Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body.

Doctors use diagnostic tests to find out the cancer's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis, which is the chance of recovery. There are different stage descriptions for different types of cancer.

There are several systems used to describe the stages of sarcomas. These systems are somewhat different from each other, but all use an overall stage to help predict a person’s prognosis.

TNM staging system

One tool that doctors use to describe the stage is the TNM system. Doctors use the results from diagnostic tests and scans to answer these questions:

  • Tumor (T): How large is the primary tumor? Where is it located?

  • Node (N): Has the tumor spread to the lymph nodes? If so, where and how many?

  • Metastasis (M): Has the cancer spread to other parts of the body? If so, where and how much?

The results are combined to determine the stage of cancer for each person. There are 4 stages: stages I through IV (1 through 4). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.

Here are more details on each part of the TNM system for sarcomas. The staging systems are different depending on the location of the sarcoma. This section describes:

  • STS in the trunk and extremities, which generally includes all of the body from the head down.

  • STS in the retroperitoneum, which is roughly defined as behind the abdominal cavity.

For TNM staging information for STS found in other parts of the body, visit the website of the American Joint Committee on Cancer. Please note that this link takes you to a separate, independent website.

Tumor (T)

Using the TNM system, the "T" plus a number is used to describe the size of the tumor and/or what nearby structures the tumor involves. Tumor size is measured in centimeters (cm). A centimeter is roughly equal to the width of a standard pen or pencil.

The T is numbered 1 through 4.

Node (N)

The "N" in the TNM staging system stands for lymph nodes. These small, bean-shaped organs help fight infection. Lymph nodes near where the cancer started are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes. STS usually does not spread to lymph nodes, and removing lymph nodes is not typically recommended for most types of sarcomas.

N0 (N plus zero): The cancer has not spread to regional lymph nodes.

N1: The cancer has spread to regional lymph nodes.

Metastasis (M)

The "M" in the TNM system describes whether the cancer has spread to other parts of the body, called distant metastasis.

M0 (M plus zero): The cancer has not metastasized.

M1: There is metastasis to another part of the body.

Grade (G)

Doctors also describe this type of cancer by its grade (G). The grade describes how much cancer cells look like healthy cells when viewed under a microscope.

The doctor compares the cancerous tissue with healthy tissue. Healthy tissue usually contains many different types of cells grouped together. If the cancer looks similar to healthy tissue and has different cell groupings, it is called “differentiated” or a “low-grade tumor.” If the cancerous tissue looks very different from healthy tissue, it is called “poorly differentiated” or a “high-grade tumor.” The cancer’s grade may help the doctor predict how quickly the cancer will spread.

There are 4 grades for sarcoma: GX (the grade cannot be evaluated), G1, G2, and G3. In general, the lower the tumor’s grade, the better the prognosis. The grades are determined based on the factors below:

  • Differentiation: How different the cancer cells are from normal tissue cells.

  • Mitotic count: How many tumor cells are dividing.

  • Tumor necrosis: How much of the tumor has cells that are dying.

Cancer stage grouping

Doctors assign the stage of the cancer by combining the T, N, M, and G classifications.

Because sarcomas can arise in any part of the body, there are different stage groupings for different sarcomas and different regions of the body. It is best to discuss your pathology results and stage with your doctor. General stage groupings for STS are defined below:

Stage I: The tumor is small and low grade (GX or G1).

Stage II: The tumor is small and higher grade (G2 or G3).

Stage III: The tumor is larger and higher grade (G2 or G3).

Stage IV: The cancer has spread to other parts of the body. The original tumor can be any size, any grade, and may or may not have spread to the regional lymph nodes (any G).

While this system is used for most types of STS, other systems may be used for specific types of sarcomas, such as Kaposi sarcoma and GIST.

Recurrent: Recurrent cancer is cancer that comes back after treatment. If the cancer does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.

Used with permission of the American College of Surgeons, Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Eighth Edition (2017), published by Springer International Publishing.

Information about the cancer’s stage will help the doctor recommend a specific treatment plan. The next section in this guide is Types of Treatment. Use the menu to choose a different section to read in this guide.