Stages of Soft Tissue Sarcoma

After soft tissue sarcoma has been diagnosed, tests are done to find out if cancer cells have spread within the soft tissue or to other parts of the body.

The process used to find out if cancer has spread within the soft tissue or to other parts of the body is called staging. Staging of soft tissue sarcoma is also based on the grade and size of the tumor, and whether it has spread to the lymph nodes or other parts of the body. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.

In addition to asking about your personal and family health history and doing a physical exam, your doctor may perform the following tests and procedures in the staging process:

• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells, white blood cells, and platelets.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the blood sample made up of red blood cells.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside of the body, such as the lung, abdomen, and pelvis, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
• PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.

The results of these tests are viewed together with the results of the tumor biopsy to find out the stage of the soft tissue sarcoma before treatment is given. Sometimes chemotherapy or radiation therapy is given as the initial treatment and afterwards the soft tissue sarcoma is staged again.

There are three ways that cancer spreads in the body.

Cancer can spread through tissue, the lymph system, and the blood:

• Tissue. The cancer spreads from where it began by growing into nearby areas.
• Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.
• Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.

Cancer may spread from where it began to other parts of the body.

When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.

• Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.
• Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.

The metastatic tumor is the same type of cancer as the primary tumor. For example, if soft tissue sarcoma spreads to the lung, the cancer cells in the lung are actually soft tissue sarcoma cells. The disease is metastatic soft tissue sarcoma, not lung cancer.

The grade of the tumor is also used to describe the cancer and plan treatment.

The grade of the tumor describes how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Low grade, mid grade, and high grade are used to describe soft tissue sarcoma:

• Low grade: In low-grade soft tissue sarcoma, the cancer cells look more like normal cells under a microscope and grow and spread more slowly than in mid-grade and high-grade soft tissue sarcoma.
• Mid grade: In mid-grade soft tissue sarcoma, the cancer cells look more abnormal under a microscope and grow and spread more quickly than in low-grade soft tissue sarcoma.
• High grade: In high-grade soft tissue sarcoma, the cancer cells look more abnormal under a microscope and grow and spread more quickly than in low-grade and mid-grade soft tissue sarcoma.

For soft tissue sarcoma of the trunk, arms, and legs, the following stages are used:

Stage I

Stage I soft tissue sarcoma of the trunk, arms, and legs is divided into stages IA and IB:

• In stage IA, the tumor is 5 centimeters or smaller and is low grade or the grade is unknown.
• In stage IB, the tumor is larger than 5 centimeters and is low grade or the grade is unknown.

Stage II

In stage II soft tissue sarcoma of the trunk, arms, and legs, the tumor is 5 centimeters or smaller and is mid grade or high grade.

Stage III

Stage III soft tissue sarcoma of the trunk, arms, and legs is divided into stages IIIA and IIIB:

• In stage IIIA, the tumor is larger than 5 centimeters but not larger than 10 centimeters and is mid grade or high grade.
• In stage IIIB, the tumor is larger than 10 centimeters and is mid grade or high grade.

Stage IV

In stage IV soft tissue sarcoma of the trunk, arms, and legs, one of the following is found:

• the tumor is any size, any grade, and has spread to nearby lymph nodes; or
• the tumor is any size, any grade, and may have spread to nearby lymph nodes. Cancer has spread to other parts of the body, such as the lung.

For soft tissue sarcoma of the retroperitoneum, the following stages are used:

Stage I

Stage I soft tissue sarcoma of the retroperitoneum is divided into stages IA and IB:

• In stage IA, the tumor is 5 centimeters or smaller and is low grade or the grade is unknown.
• In stage IB, the tumor is larger than 5 centimeters and is low grade or the grade is unknown.

Stage II

In stage II soft tissue sarcoma of the retroperitoneum, the tumor is 5 centimeters or smaller and is mid grade or high grade.

Stage III

Stage III soft tissue sarcoma of the retroperitoneum is divided into stages IIIA and IIIB:

• In stage IIIA, the tumor is larger than 5 centimeters but not larger than 10 centimeters and is mid grade or high grade.
• In stage IIIB, one of the following is found:
  • the tumor is larger than 10 centimeters and is mid grade or high grade; or
  • the tumor is any size, any grade, and has spread to nearby lymph nodes.

Stage IV

In stage IV soft tissue sarcoma of the retroperitoneum, the tumor is any size, any grade, and may have spread to nearby lymph nodes. Cancer has spread to other parts of the body, such as the lung.

There is no standard staging system for soft tissue sarcoma of the head, neck, chest, or abdomen.

Soft tissue sarcoma can recur (come back) after it has been treated.

The cancer may come back in the same soft tissue or in other parts of the body.