What is a soft tissue sarcoma?

A soft tissue sarcoma is a growth of abnormal cells in the body's soft tissues. These tissues include the muscles, lymph and blood vessels, nerves, and fat. It can also include cartilage and other connective tissue. When cancer cells are found in the tissue, the tumour is called malignant.

Sarcoma is another name for a malignant soft tissue tumour. Sarcomas can spread to other parts of the body, like the lungs.

What are some common types?

Some common types of soft tissue sarcomas in children include:

Rhabdomyosarcomas.

This is the most common type of soft tissue tumour in children. It can form anywhere in the body, but is often found in the head and neck area, the arms and legs, or in the genitals and urinary tract.

Synovial sarcomas.

This is often found near joints, such as near the knee, but may appear in other places.

Peripheral nerve sheath tumours.

These tumours are made up of nerve cells.

Infantile fibrosarcomas.

This is often found in the torso and extremities. It's more common in very young children.

Other types of soft tissue tumours may appear on the skin, nerves, belly, and limbs.

What are the symptoms?

Your child may feel a swelling or lump on his or her body. Usually there isn't any pain.

How are they diagnosed?

The doctor will ask about your child's symptoms and past health and will examine your child. If the doctor can feel a lump or mass in the soft tissue, or if your child has other symptoms, your child will get some tests. The tests can help find out if it's cancer. They can also help the doctor figure out the best treatment for the tumour.

The doctor may also find a tumour when taking X-rays or images for another problem.

• Your child may have one or more imaging tests to get a better look at the tumour. These may include:
  • X-rays.
  • Ultrasound.
  • CT scan.
  • MRI scan.
  • PET or other nuclear scan.
• Your child may need blood tests and other lab work.
• Your child may need a biopsy so a sample of the tumour can be looked at under a microscope. This sample may also be used to test for biomarkers. They will help with planning treatment.
• Doctors may also examine other parts of your child's body to make sure that the tumour hasn't spread.

The doctor may talk to you about what "stage" your child's cancer is. The stage refers to how large the tumour is and how far it has spread. It also includes the tumour grade. The grade describes what the cancer cells look like and how likely they are to grow and spread.

These can help the doctor find out what type of treatment your child may need. And they may help to find a clinical trial that has treatments for your child's type of cancer.

How are they treated?

Treatment for a soft tissue sarcoma is based on the stage, type, and location of the cancer and other things, such as your child's age. The main treatments include:

Surgery.

Your child may need surgery to remove cancer from the tissue.

Radiation therapy.

This uses high-dose X-rays to destroy cancer cells and shrink tumours. Radiation may be used before, during, or after surgery.

In some cases, other treatments may be used, such as:

Chemotherapy.

These medicines kill fast-growing cells, including cancer cells and some normal cells.

Targeted therapy.

These medicines target cancer cells and may cause less harm to normal cells. They help keep cancer from growing or spreading.

The doctor will talk with you about the options and then make a treatment plan for your child.

What are some things to think about?

• Some tumours are aggressive and need treatment right away. But most cancer grows slowly enough that you can take a little time to find out more about your child's cancer as you decide about treatment.
• Talk to your child. Answer all of your child's questions honestly. If you don't know the answers, help your child find out.
• Ask any questions you might have. You can talk to the doctor, nurses, counsellors, and other advisors.
• Talk to family, friends, and supporters. Get the kinds of help you need.
• Think about getting a second opinion from another doctor. Before your child starts major treatment, it's a good idea to check with another doctor about the type of cancer your child has and what stage it is. Your child's doctor can recommend someone for a second opinion.