Sarcoma

It's not clear what causes most sarcomas.

In general, cancer forms when changes (mutations) happen in the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide.

Mutations might tell cells to grow and divide uncontrollably and to continue living when normal cells would die. If this happens, the accumulating abnormal cells can form a tumor. Cells can break away and spread (metastasize) to other parts of the body.

Risk factors

Factors that can increase the risk of sarcoma include:

• Inherited syndromes. Some syndromes that increase the risk of cancer can be passed from parents to children. Examples of syndromes that increase the risk of sarcoma include familial retinoblastoma and neurofibromatosis type 1.
• Radiation therapy for cancer. Radiation treatment for cancer increases the risk of developing a sarcoma later.
• Chronic swelling (lymphedema). Lymphedema is swelling caused by a backup of lymph fluid that occurs when the lymphatic system is blocked or damaged. It increases the risk of a type of sarcoma called angiosarcoma.
• Exposure to chemicals. Certain chemicals, such as some industrial chemicals and herbicides, can increase the risk of sarcoma that affects the liver.
• Exposure to viruses. The virus called human herpesvirus 8 can increase the risk of a type of sarcoma called Kaposi's sarcoma in people with weakened immune systems.

Tests and procedures used to diagnose sarcoma and determine its extent (stage) include:

• A physical exam. Your doctor will likely do a physical exam to better understand your symptoms and look for other clues that will help with your diagnosis.
• Imaging tests. Which imaging tests are right for you will depend on your situation. Some tests, such as X-rays, are better for seeing bone problems. Other tests, such as MRI, are better for seeing connective tissue problems. Other imaging tests might include ultrasound, CT, bone scans and positron emission tomography (PET) scans.

• Removing a sample of tissue for testing (biopsy). A biopsy is a procedure to remove a piece of suspicious tissue for lab testing. Sophisticated lab tests can determine whether the cells are cancerous and what kind of cancer they represent. Tests can also reveal information that's helpful for choosing the best treatments.

  
  

  How a biopsy sample is collected depends on your particular situation. It could be removed with a needle passed through the skin or cut away during an operation. Sometimes a biopsy is done at the same time as surgery to remove the cancer.

Once your doctor determines you have sarcoma, he or she might recommend additional tests to look for signs that the cancer has spread.

Sarcoma is usually treated with surgery to remove the cancer. Other treatments might be used before or after surgery. Which treatments are best for you will depend on the type of sarcoma, its location, how aggressive the cells are and whether cancer has spread to other parts of your body.

Treatment for sarcoma might involve:

• Surgery. The goal of surgery for sarcoma is to remove all of the cancer cells. Sometimes it's necessary to amputate an arm or leg to remove all of the cancer, but surgeons try to preserve limb function when possible. Sometimes all of the cancer can't be removed without hurting important structures, such as nerves or organs. In these situations, the surgeons work to remove as much of the sarcoma as possible.
• Radiation therapy. Radiation therapy uses high-powered energy beams, such as X-rays and protons, to kill cancer cells. The radiation can come from a machine that moves around your body directing the beams of energy (external beam radiation). Or the radiation might be placed in your body temporarily (brachytherapy). Sometimes radiation is done during an operation to remove the cancer (intraoperative radiation).
• Chemotherapy. Chemotherapy is a drug treatment that uses chemicals to kill cancer cells. Some types of sarcoma are more likely to respond to chemotherapy treatment than others.
• Targeted therapy. Targeted therapy is a drug treatment that uses medicines that attack specific weaknesses in cancer cells. Your doctor may have your sarcoma cells tested to see if they are likely to respond to targeted therapy drugs.
• Immunotherapy. Immunotherapy is a drug treatment that uses your immune system to fight cancer. Your body's disease-fighting immune system may not attack your cancer because the cancer cells produce proteins that blind the immune system cells. Immunotherapy drugs work by interfering with that process.
• Ablation therapy. Ablation therapy treatments destroy cancer cells by applying electricity to heat the cells, very cold liquid to freeze the cells or high-frequency ultrasound waves to damage the cells.

Coping and support

With time, you'll find what helps you cope with the uncertainty and distress that comes with a cancer diagnosis. Until then, you may find that it helps to:

• Learn enough about sarcoma to make decisions about your care. Ask your doctor about your cancer, including your test results, treatment options and, if you like, your prognosis. As you learn more about cancer, you may become more confident in making treatment decisions.
• Keep friends and family close. Keeping your close relationships strong will help you deal with your cancer. Friends and family can provide the practical support you'll need, such as helping take care of your home if you're in the hospital. And they can serve as emotional support when you feel overwhelmed by cancer.

• Find someone to talk with. Find a good listener who is willing to hear you talk about your hopes and fears. This may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or cancer support group also may be helpful.

  Ask your doctor about support groups in your area. Other sources of information include the National Cancer Institute and the American Cancer Society.