• Soft Tissue Sarcoma

    Soft tissue sarcomas are cancerous tumors that begin in the tissues that connect, support or surround the body's organs and structures, known as soft tissues. These tissues include muscle, tendon, synovial tissue (around joints), fat, blood vessels, lymph vessels, and nerves. Soft tissue sarcomas can develop almost anywhere in the body, but in children they are most common in the arms, legs, chest, and abdomen.

    • Soft tissue sarcomas are rare, comprising less than 1% of all new cancer cases per year and just 3% of all childhood tumors.
    • In the United States, about 900 children and adolescents are diagnosed with soft tissue sarcomas each year.
    • Doctors are not sure what causes soft tissue sarcomas to emerge, but a genetic link is suspected. Some inherited diseases, such as Li Fraumeni syndrome and neurofibromatosis type 1, increase the risk of developing a soft tissue sarcoma.

    Soft tissue sarcomas affect tissue that is elastic and easily moved, which means that a tumor may exist for a long time before being discovered, growing larger and pushing aside surrounding tissue.

    Soft Tissue Sarcoma Treatment at Dana-Farber/Boston Children's

    Children with soft tissue sarcoma are treated at Dana-Farber/Boston Children's through our Bone and Soft Tissue Tumor Program. Our integrated pediatric oncology program offers the combined expertise of a leading cancer center and a world-renown children’s hospital.

    • We provide the full set of options that can be used to treat bone and soft tissue tumors, and our solid tumor treatment team can help you determine which option is best for your child.
    • Our pediatric oncologists have access to, and often lead, some of the most innovative clinical trials for soft tissue sarcomas.
    • Our surgeons have specialized expertise in complex surgeries, and our radiation oncologists have access to the newest radiation therapy techniques that may also be used in the care of a child with soft tissue sarcoma

    What are types of soft tissue tumors?

    There are many types of soft tissue sarcomas.

    • Adamantinoma is a cancerous tumor found most often in the shin bone (tibia) and jaw bone (mandible).
    • Alveolar soft part sarcoma is a tumor that starts in connective tissue, including fat, muscle, and nerve.
    • Desmoid tumors (also called aggressive fibromytosis) are tumors that form in fibrous tissue that makes up tendons and ligaments.
    • Epithelioid hemangioendotheliomais a rare vascular tumor that sometimes behaves like a cancer but in most cases is benign.
    • Ewing sarcoma is a cancer that grows in bone or soft tissue around bone.
    • Fibrosarcoma is a tumor that originates in connective tissue at the end of bones in the arms or legs and spreads to surrounding soft tissue.
    • Hemangiopericytoma originates in the walls of capillaries, the tiny blood vessels located within the tissues of the body
    • Inflammatory myofibroblastic tumor are soft tissue masses that can grow in any part of the body.
    • Liposarcoma is a tumor that develops in fat tissue, most often in the abdominal cavity.
    • Peripheral nerve sheath tumor is a tumor that forms in cells that surround nerves.
    • Rhabdomyosarcoma is the most common soft tissue sarcoma; it begins in skeletal muscles.
    • Synovial cell sarcoma is a malignant tumor in soft tissues around joints, most commonly the knee.
    • Undifferentiated or spindle cell sarcoma involves the connective tissue; the cells are spindle-shaped when examined under a microscope.

    What are the causes and symptoms of soft tissue sarcoma?

    As a parent, you undoubtedly want to know what may have caused your child’s tumor. In most cases, doctors don't know what leads to soft tissue sarcomas, but many suspect that the cancer's origin is genetic. Soft tissue sarcoma is not associated with environmental factors, and it is important to keep in mind that there is nothing you could have done, or avoided doing, that would have prevented the tumor from developing.

    Limited studies have shown a possible link between soft tissue sarcomas and the development of other types of cancer. Some inherited diseases have also been associated with an increased risk of developing soft tissue sarcomas including Li-Fraumeni syndrome or neurofibromatosis. For some soft tissue tumors, there seems to an association with an Epstein-Barr virus infection.

    While each disease has its own specific symptoms, the most common symptoms of soft tissue sarcoma include:

    • Painless swelling or a lump
    • Pain or soreness caused by compressed nerves or muscles
    • Limping or other difficulty using the legs and feet

    Keep in mind that some similar symptoms can be associated with more common medical problems and conditions. It is important to consult your child's physician for a diagnosis.

    How is soft tissue sarcoma diagnosed?

    The first step in treating your child is forming an accurate and complete diagnosis. A physician may order a number of different tests to diagnose soft tissue sarcoma, determine its exact type and whether it has spread. In addition to a medical history and physical exam, these may include:

    • Blood and urine tests, including a complete blood count and blood chemistry.
    • Computerized tomography (CT or CAT) scan, which involves taking detailed images of any part of the body, including the bones, muscles, and fat.
    • Magnetic resonance imaging (MRI), which is a test that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
    • X-ray, which is a test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs.
    • Bone scans or PET scan, which include taking pictures or x-rays of the bone after a dye has been injected that is absorbed by bone tissue. These are used to detect tumors and bone abnormalities.
    • Biopsy, a sample taken of the primary tumor and/or metastatic lesions to provide definitive information about tumor type.

    There may be other diagnostic tests that your doctor will discuss with you depending on your child's individual situation. After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and outline the best possible treatment options.

    What are soft tissue sarcoma treatments?

    Soft tissue sarcoma treatment typically involves an approach that combines surgery, chemotherapy, and radiation. However, in recent years, pediatric oncology physician scientists at Dana-Farber/Boston Children’s and other leading cancer centers have learned more about the specific genetic mutations within soft tissue sarcomas. Some clinical trials are now testing medicines that target these specific mutations (known as precision medicine). It is possible that these targeted therapies may play a larger role in soft tissue sarcoma treatment in the future.

    Currently, soft tissue sarcoma treatment is likely to include:

    • Surgery: Surgery is often a first step, allowing doctors to form a complete diagnosis of the tumor type and providing information on the stage of the disease. If your child’s leg or arm is affected, your child may receive:
      • limb-salvage surgery, to help preserve the limb by removing the tumor and wide margins of healthy tissue surrounding the tumor
      • rotationplasty, a partial amputation that preserves a cancer-free lower leg, attaches it to the thighbone and uses the ankle as a knee joint
      • amputation surgery, which in rare cases may be necessary (for example, if it involves the nerves and blood vessels)
    • Radiation therapy:This treatment can help stop the growth of abnormal cells in specific areas of the body. Radiation therapy uses high-energy rays from a specialized machine to damage or kill abnormal cells. Our doctors use precisely targeted and dosed radiation to kill cancer cells left behind after your child's surgery.
    • Chemotherapy:These medicines can help stop the growth of abnormal cells throughout the body. Chemotherapy is systemic treatment, meaning it is introduced to the bloodstream and travels throughout the body to kill or slow the growth of targeted cells. Different groups of chemotherapy drugs work in different ways, and can be taken in a variety of ways including orally or intravenously.

    While chemotherapy can be quite effective in treating certain cancers, the agents don't completely differentiate normal healthy cells from abnormal cells. Because of this, your child could have adverse side effects during treatment.

    What is the latest soft tissue sarcoma research?

    At Dana-Farber/Boston Children's, your child will have access to cutting-edge therapies being tested by the nation's top researchers in pediatric cancer. Our scientists are conducting numerous research studies to help doctors better understand and treat soft tissue sarcomas. These include:

    • genomic assessment of soft tissue sarcomas, and investigation of targeted medicines to treat tumors with particular genetic profiles (precision medicine)
    • angiogenesis inhibitors, which are substances that might be able to prevent the growth of tumors
    • biological therapies, which harness the body's immune system to fight cancer or lessen side effects (immunotherapy)

    We are also the New England Phase I Center for the Children's Oncology Group, a group of cancer researchers from around the world dedicated to finding new treatments for pediatric cancer.

    Clinical trials

    For many children with rare, recurrent, or hard-to-treat conditions, clinical trials provide new options.

    What is the long term outlook for children with soft tissue sarcoma?

    Over the past 30 years, there has been drastic improvement in survival for children with soft tissue sarcomas. Complete surgical removal can control the tumor in about 80 percent of cases. Adding radiation therapy after surgery can increase cure rates to 90 to 95 percent. If the tumor can’t be completely removed or it has spread to other parts of the body, the prognosis is poorer. Outcomes for progressive or recurrent soft tissue sarcoma are poor.

    Some children who are treated for soft tissue sarcoma and other pediatric cancers can experience significant long-term problems as a result of their treatment. All children who have been treated for cancer require ongoing, specialized cancer survivorship care.

    Through the David B. Perini, Jr. Quality of Life Clinic, our cancer survivorship clinic, childhood cancer survivors receive a comprehensive follow-up evaluation from their cancer care team. In addition to meeting with your pediatric oncologists, your child may see one of our endocrinologists, cardiologists, neurologists, neuro-psychologists, and/or alternative/complementary therapy specialists. We also offer patient and family education, psychosocial assessment, genetic counseling, reproductive counseling and opportunities to speak with other childhood cancer survivors.