Alveolar Soft Part Sarcoma

Also called: ASPS

What is alveolar soft-part sarcoma?

Alveolar soft-part sarcoma is a rare type of cancer called a sarcoma, which is a malignant tumor affecting soft tissues like fat, muscle and nerves. It occurs mainly in children, but can also appear in adults.

This type of tumor grows slowly but spreads and returns easily. It generally starts in the limbs (legs and arms), as well as the head and neck.

The cause of alveolar soft-part sarcoma is not clear. It is not passed on from parents to children through the genes.

Alveolar soft-part sarcoma usually appears as a non-painful lump in a leg or buttock. Nodules form the lump tend to travel to the lungs, brain and liver. Alveolar soft-part sarcoma does not usually produce symptoms right away. So, it can spread and grow before its cells have become large enough to be noticed and treated.

How common is alveolar soft-part sarcoma?

Alveolar soft-part sarcoma is a very rare form of cancer. Sarcomas make up about 15% of all childhood cancers. Only 1% of all sarcoma cases are alveolar soft-part sarcoma. Fewer than 80 cases are diagnosed per year in the U.S.

What are the signs and symptoms of alveolar soft-part sarcoma?

Alveolar soft-part sarcoma can go unnoticed for a long time before it is diagnosed. When the tumor grows large enough, it starts pushing on the tissues and structures around it. Symptoms vary depending on the location of the tumor and may include the following:

  • A painless swelling or mass in the leg, buttocks, neck or chest
  • Secondary symptoms caused by the tumor pressing on nerves or muscles in the affected area
  • Decreased range of motion in the arms and legs
  • Limping
  • Muscle stiffness

How is alveolar soft-part sarcoma treated?

A team of doctors from many specialties will work to determine a course of treatment for alveolar soft-part sarcoma. The most common option combines the following therapies:

  • Surgery—A surgical oncologist (a cancer surgeon) removes the tumor and any surrounding tissues (margin). Since alveolar soft-part sarcoma often comes back after treatment, the surgeon may want to take a wide margin of tissue to get all of the cancer. If the tumor is in an arm or leg, this surgery might include removal of part or all of the arm or leg.
  • Radiation (radiotherapy)—In this treatment, a radiation oncologist uses light energy such as high-energy X-rays to destroy or reduce the size of tumor cells. It is usually painless but can cause temporary side effects such as skin problems, diarrhea, fatigue and stomach problems.
  • Targeted drug therapy—Traditional chemotherapy (drugs that slow tumor cell growth or destroy it) usually is does not work well for alveolar soft-part sarcoma. In addition, the effects of chemo are severe and affect many parts of the body, making it a poor treatment choice for this cancer. Researchers have turned their focus to more targeted therapies that destroy the alveolar soft-part sarcoma cells without harming nearby healthy tissues. Such therapies include drugs such as cediranib and sunitinib. These drugs starve alveolar soft-part sarcoma tumors by cutting off blood flow to them. These drugs are being tested in clinical trials.

What are the survival rates for alveolar soft-part sarcoma?

Because alveolar soft-part sarcoma is so rare, there are not many large-scale studies of its survival rate. Its prognosis is poor, and the disease is often fatal. Even so, alveolar soft-part sarcoma sometimes progresses slowly enough that it does not become fatal until years or even decades after it is diagnosed.

The overall survival rate for alveolar soft-part sarcoma has been reported as 45 to 80 percent at 10 years and 15 percent at 20 years. Children generally survive longer with the disease than adults do.

The low rate of long-term survival for alveolar soft-part sarcoma is likely caused by its lack of symptoms and tendency to spread (metastasize) to other tissues.

Why choose St. Jude for your child’s alveolar soft-part sarcoma treatment?

  • St. Jude has been a pioneer in limb-sparing surgical techniques. Our surgeons continue to explore new limb-sparing techniques to improve survival and help children live normal lives after treatment.
