Soft Tissue Sarcomas

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. These sarcomas are rare, comprising less than 1 percent of all new cancer cases per year and just 3 percent 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.

While each disease has its own specific symptoms, the most common symptoms of soft tissue sarcoma may include a painless lump, soreness caused by compressed nerves or 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.

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.

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
• Computerized tomography (CT or CAT) scan
• Magnetic resonance imaging (MRI)
• X-ray
• Ultrasound
• Bone scans
• Bone marrow biopsy and/or aspiration
• Biopsy

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.

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
• Radiation therapy
• Chemotherapy

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.

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.

Children with soft tissue sarcoma are treated at Dana-Farber/Boston Children's Cancer and Blood Disorders Center through our Bone and Soft Tissue Tumors 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.

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
• Angiogenesis inhibitors, which are substances that might be able to prevent the growth of tumors
• Biological therapies that harness the body's immune system to fight cancer

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.

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