Adult Soft Tissue Sarcoma

*Adult soft tissue sarcoma facts written by Melissa Conrad Stöppler, MD

• A sarcoma is a cancer that forms in soft tissues of the body such as muscles, fat tissue, blood vessels, tendons, and nerves. Tumors of these tissues can also be benign (non-cancerous).
• There are over 50 different kinds of soft tissue sarcoma. Examples include liposarcoma, synovial sarcoma, rhabdomyosarcoma, epithelioid sarcoma, and angiosarcoma.
• A hard lump or mass beneath the skin is the most common sign or symptom of sarcoma.
• Sarcomas may not cause signs or symptoms until they have grown to a large size.
• Biopsy of the tissue is required to diagnose that a sarcoma is present and determine the exact type of the tumor.
• Surgery is the most common treatment for soft tissue sarcoma. Radiation therapy and chemotherapy may also be used in some cases.
• The prognosis (outlook) for soft tissue sarcoma depends upon the exact type, location, and extent of spread of the tumor, as well as the underlying health condition of the patient.

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 head, neck, arms, legs, trunk, and abdomen.

There are many types of soft tissue sarcoma. The cells of each type of sarcoma look different under a microscope, based on the type of soft tissue in which the cancer began.

Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. Talk with your doctor if you think you may be at risk. Risk factors for soft tissue sarcoma include the following inherited disorders:

• Retinoblastoma.
• Neurofibromatosis type 1 (NF1; von Recklinghausen disease).
• Tuberous sclerosis (Bourneville disease).
• Familial adenomatous polyposis (FAP; Gardner syndrome).
• Li-Fraumeni syndrome.
• Werner syndrome (adult progeria).
• Nevoid basal cell carcinoma syndrome (Gorlin syndrome).

Other risk factors for soft tissue sarcoma include the following:

• Past treatment with radiation therapy for certain cancers.
• Being exposed to certain chemicals, such as Thorotrast (thorium dioxide), vinyl chloride, or arsenic.
• Having swelling (lymphedema) in the arms or legs for a long time.

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 signs or symptoms until they get very big. As the sarcoma grows bigger and presses on nearby organs, nerves, muscles, or blood vessels, signs and symptoms may include:

• Pain.
• Trouble breathing.

Other conditions may cause the same signs and symptoms. Check with your doctor if you have any of these problems.

If your doctor thinks you may have a soft tissue sarcoma, a biopsy will be done. The type of biopsy will be based on the size of the tumor and where it is in the body. There are three 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.
• Excisional biopsy: The removal of an entire lump or area of tissue that doesn’t look normal.

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 tissue samples checked by a pathologist who has experience in diagnosing soft tissue sarcoma.

The following tests may be done on the tissue that was removed:

• Immunohistochemistry: A test that uses antibodies to check for certain antigens in a sample of tissue. The antibody is usually linked to a radioactive substance or a dye that causes the tissue to light up under a microscope. This type of test may be used to tell the difference between different types of cancer.
• Light and electron microscopy: A laboratory test in which cells in a sample of tissue are viewed under regular and high-powered microscopes to look for certain changes in the cells.
• Cytogenetic analysis: A laboratory test in which cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes.
• FISH (fluorescence in situ hybridization): A laboratory test used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA attach to certain genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light.
• Flow cytometry: A laboratory test that measures the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser or other type of light. The measurements are based on how the light-sensitive dye reacts to the light.

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.
• How fast the cancer cells are growing and dividing.
• Where the tumor is in the body.
• Whether all of the tumor is removed by surgery.
• The patient's age and general health.
• Whether the cancer has recurred (come back).

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.
• 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 and abdomen, 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.

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.

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 following stages are used for adult soft tissue sarcoma:

Stage I

Stage I is divided into stages IA and IB:

• In stage IA, the tumor is low-grade (likely to grow and spread slowly) and 5 centimeters or smaller. It may be either superficial (in subcutaneous tissue with no spread into connective tissue or muscle below) or deep (in the muscle and may be in connective or subcutaneous tissue).
• In stage IB, the tumor is low-grade (likely to grow and spread slowly) and larger than 5 centimeters. It may be either superficial (in subcutaneous tissue with no spread into connective tissue or muscle below) or deep (in the muscle and may be in connective or subcutaneous tissue).

Stage II

Stage II is divided into stages IIA and IIB:

• In stage IIA, the tumor is mid-grade (somewhat likely to grow and spread quickly) or high-grade (likely to grow and spread quickly) and 5 centimeters or smaller. It may be either superficial (in subcutaneous tissue with no spread into connective tissue or muscle below) or deep (in the muscle and may be in connective or subcutaneous tissue).
• In stage IIB, the tumor is mid-grade (somewhat likely to grow and spread quickly) and larger than 5 centimeters. It may be either superficial (in subcutaneous tissue with no spread into connective tissue or muscle below) or deep (in the muscle and may be in connective or subcutaneous tissue).

Stage III

In stage III, the tumor is either:

• high-grade (likely to grow and spread quickly), larger than 5 centimeters, and either superficial (in subcutaneous tissue with no spread into connective tissue or muscle below) or deep (in the muscle and may be in connective or subcutaneous tissue); or
• any grade, any size, and has spread to nearby lymph nodes.

Stage III cancer that has spread to the lymph nodes is advanced stage III.

Stage IV

In stage IV, the tumor is any grade, any size, and may have spread to nearby lymph nodes. Cancer has spread to distant parts of the body, such as the lungs.

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.

Different types of treatments are available for patients with adult soft tissue sarcoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Three types of standard treatment are used:

Surgery

Surgery is the most common treatment for adult soft tissue sarcoma. For some soft-tissue sarcomas, removal of the tumor in surgery may be the only treatment needed. The following surgical procedures may be used:

• Mohs microsurgery: A procedure in which the tumor is cut from the skin in thin layers. During surgery, the edges of the tumor and each layer of tumor removed are viewed through a microscope to check for cancer cells. Layers continue to be removed until no more cancer cells are seen. This type of surgery removes as little normal tissue as possible and is often used where appearance is important, such as on the skin.
• Wide local excision: Removal of the tumor along with some normal tissue around it. For tumors of the head, neck, abdomen, and trunk, as little normal tissue as possible is removed.
• Limb-sparing surgery: Removal of the tumor in an arm or leg without amputation, so the use and appearance of the limb is saved. Radiation therapy or chemotherapy may be given first to shrink the tumor. The tumor is then removed in a wide local excision. Tissue and bone that are removed may be replaced with a graft using tissue and bone taken from another part of the patient's body, or with an implant such as artificial bone.
• Amputation: Surgery to remove part or all of a limb or appendage, such as an arm or leg. Amputation is rarely used to treat soft tissue sarcoma of the arm or leg.
• Lymphadenectomy: A surgical procedure in which lymph nodes are removed and a sample of tissue is checked under a microscope for signs of cancer. This procedure is also called a lymph node dissection.

Radiation therapy or chemotherapy may be given before or after surgery to remove the tumor. When given before surgery, radiation therapy or chemotherapy will make the tumor smaller and reduce the amount of tissue that needs to be removed during surgery. Treatment given before surgery is called neoadjuvant therapy. When given after surgery, radiation therapy or chemotherapy will kill any remaining cancer cells. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy:

• External radiation therapy uses a machine outside the body to send radiation toward the cancer.
• Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.

Intensity-modulated radiation therapy (IMRT) is a type of 3-dimensional (3-D) radiation therapy that uses a computer to make pictures of the size and shape of the tumor. Thin beams of radiation of different intensities (strengths) are aimed at the tumor from many angles. This type of external radiation therapy causes less damage to nearby healthy tissue and is less likely to cause dry mouth, trouble swallowing, and damage to the skin. The way the radiation therapy is given depends on the type and stage of the cancer being treated. External radiation therapy and internal radiation therapy may be used to treat adult soft tissue sarcoma.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Regional chemotherapy

Clinical trials are studying ways to improve the effect of chemotherapy on tumor cells, including the following:

• Regional hyperthermia therapy: A treatment in which tissue around the tumor is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to chemotherapy.
• Isolated limb perfusion: A procedure that sends chemotherapy directly to an arm or leg in which the cancer has formed. The flow of blood to and from the limb is temporarily stopped with a tourniquet, and anticancer drugs are put directly into the blood of the limb. This sends a high dose of drugs to the tumor.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.

Stage I Adult Soft Tissue Sarcoma

Treatment of stage I soft tissue sarcoma may include the following:

• Surgery to remove the tumor, such as Mohs microsurgery for small sarcomas of the skin, wide local excision, or limb-sparing surgery.
• Radiation therapy before and/or after surgery.

Stage II Adult Soft Tissue Sarcoma and Stage III Adult Soft Tissue Sarcoma That Has Not Spread to Lymph Nodes

Treatment of stage II adult soft tissue sarcoma and stage III adult soft tissue sarcoma that has not spread to lymph nodes may include the following:

• Surgery to remove the tumor, such as wide local excision or limb-sparing surgery.
• Radiation therapy before or after surgery.
• Radiation therapy or chemotherapy before limb-sparing surgery. Radiation therapy may also be given after surgery.
• High-dose radiation therapy for tumors that cannot be removed by surgery.

Stage III Adult Soft Tissue Sarcoma That Has Spread to Lymph Nodes (Advanced)

Treatment of stage III adult soft tissue sarcoma that has spread to lymph nodes (advanced) may include the following:

• Surgery (wide local excision) with lymphadenectomy. Radiation therapy may also be given after surgery.
• A clinical trial of surgery followed by chemotherapy.
• A clinical trial of regional hyperthermia therapy.

Stage IV Adult Soft Tissue Sarcoma

Treatment of stage IV adult soft tissue sarcoma may include the following:

• Chemotherapy.
• Surgery to remove cancer that has spread to the lungs.

Treatment of recurrent adult soft tissue sarcoma may include the following:

• Surgery (wide local excision) followed by radiation therapy.
• Surgery (amputation; rarely done).
• Surgery to remove cancer that has recurred in the lungs.
• Chemotherapy.
• A clinical trial of isolated limb perfusion.