Adult Soft Tissue Sarcoma

General Information | Treatment Options | Additional Resources

General Information
  • About
  • Risk Factors
  • Signs & Symptoms
  • Detection
  • Stages

General Information About Adult Soft Tissue Sarcoma

Adult soft tissue sarcoma is a disease in which malignant (cancer) cells form in the soft tissues of the body.

The soft tissues of the body include the muscles, tendons (bands of fiber that connect muscles to bones), fat, blood vessels, lymph vessels, nerves, and tissues around joints. Adult soft tissue sarcomas can form almost anywhere in the body, but are most common in the legs, abdomen, arms, and trunk.

There are many types of soft tissue sarcoma. One type that forms in the wall of the stomach, intestines, or rectum is called a gastrointestinal stromal tumor (GIST). The cells of each type of sarcoma look different under a microscope, based on the type of soft tissue in which the cancer began.

Having certain inherited disorders can increase the risk of developing adult soft tissue sarcoma.

Anything that increases your risk of getting a disease is called a risk factor. Risk factors for soft tissue sarcoma include the following inherited disorders:

  • Retinoblastoma.
  • Neurofibromatosis type 1 (von Recklinghausen disease or NF1).
  • Tuberous sclerosis.
  • Familial adenomatous polyposis (FAP).
  • Li-Fraumeni syndrome.
  • Werner syndrome.
  • Basal cell nevus syndrome.

Other risk factors for soft tissue sarcoma include past treatment with radiation therapy during childhood or for the following types of cancer:

  • Retinoblastoma.
  • Breast cancer.
  • Lymphoma.
  • Cervical cancer.

Possible signs of adult soft tissue sarcoma include a lump or swelling in soft tissue of the body.

A sarcoma may appear as a painless lump under the skin, often on an arm or a leg. Sarcomas that begin in the abdomen may not cause symptoms until they become very large. As the sarcoma grows larger and presses on nearby organs, nerves, muscles, or blood vessels, symptoms may include:

  • Pain.
  • Trouble breathing.

Other conditions may cause the same symptoms that soft tissue sarcomas do. A doctor should be consulted if any of these problems occur.

Adult soft tissue sarcoma is diagnosed with a biopsy.

If a soft tissue sarcoma is suspected, a biopsy will be done. The type of biopsy that is done will be based on the size and location of the tumor. There are two types of biopsy that may be used:

  • Incisional biopsy: The removal of part of a lump or a sample of tissue.
  • Core biopsy: The removal of tissue using a wide needle.

Samples will be taken from the primary tumor, lymph nodes, and other suspicious areas. A pathologist views the tissue under a microscope to look for cancer cells and to find out the grade of the tumor. The grade of a tumor depends on how abnormal the cancer cells look under a microscope and how quickly the cells are dividing. High-grade tumors usually grow and spread more quickly than low-grade tumors. Because soft tissue sarcoma can be hard to diagnose, patients should ask to have biopsy samples checked by a pathologist who has experience in diagnosing soft tissue sarcoma.

Certain factors affect treatment options and prognosis (chance of recovery).

The treatment options and prognosis (chance of recovery) depend on the following:

  • The type of soft tissue sarcoma.
  • The size, grade, and stage of the tumor.
  • Where the tumor is in the body.
  • Whether the entire tumor is removed by surgery.
  • The patient's age and general health.
  • Whether the cancer has recurred (come back).

Stages of Adult Soft Tissue Sarcoma

After adult 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, whether it is superficial (close to the skin's surface) or deep, 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.

The following tests and procedures may be used in the staging process:

  • Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
  • X-rays: An x-ray is a type of energy beam that can go through the body onto film, making pictures of areas inside the body.
  • Laboratory tests: Medical procedures that test samples of tissue, blood, urine, or other substances in the body. These tests help to diagnose disease, plan and check treatment, or monitor the disease over time.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside of the body, 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).

The results of these tests are viewed together with the results of the tumor biopsies to determine the stage of the soft tissue sarcoma.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

  • Through tissue. Cancer invades the surrounding normal tissue.
  • Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
  • Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for adult soft tissue sarcoma:Stage I

In stage I, the tumor is any size, low-grade (likely to grow and spread slowly), and may be either superficial (close to the skin's surface) or deep.

Stage II

In stage II, the tumor is high-grade (likely to grow and spread quickly) and either:

  • 5 centimeters or smaller and can be superficial (close to the skin's surface) or deep; or
  • larger than 5 centimeters and superficial.

Stage III

In stage III, the tumor is high-grade, larger than 5 centimeters, and deep.

Stage IV

In stage IV, the tumor is any size, any grade, and has spread to nearby lymph nodes or to other parts of the body.

Recurrent Adult Soft Tissue Sarcoma

Recurrent adult soft tissue sarcoma is cancer that has recurred (come back) after it has been treated. The cancer may come back in the same soft tissue or in other parts of the body.

Cancer information from the NCI PDQ service