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 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.
Children
with soft tissue sarcoma are treated at Dana-Farber/Boston Children's 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.
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.
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.
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.
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.
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.
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.