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Clear Cell Sarcoma

What is clear cell sarcoma? 

Clear cell sarcoma, or CCS, is a type of cancer called soft tissue sarcoma. CCS tumors occur most often in the arms, legs, feet, and hands. But, CCS can grow throughout the torso, including the stomach and intestines. CCS has also been found in the genitals and head. Clear cell sarcoma gets its name from the fact that the cells of the tumor look clear under a microscope. 

How common is clear cell sarcoma?

Sarcomas are rare cancers and CCS is a rare type of sarcoma, making up 1% of sarcoma cases. It is most often found in teens and young adults in their 20s. The average age at diagnosis is 25 years old. But CCS is so rare, we don’t know exactly how many people have it.

How is clear cell sarcoma diagnosed?

CCS is hard to diagnose. At first, some patients may be diagnosed with malignant melanoma of soft parts because cells of both of these cancers look alike under a microscope. But, there are certain genetic features that are very common in CCS that are not found in melanoma. It is important to go to a doctor that specializes in sarcoma. You can contact MyPART for help finding experts near you.

Many people with CCS do not have symptoms at first. Later, when the tumor gets larger, symptoms can include:

  • Lump under the skin that is sometimes painful
  • Weight loss for no known reason
  • Fatigue
  • Night sweats

Imaging: Your doctor will use scans such as MRI and CT to see where the tumor is and how big it is. They will also check for signs that the tumor has spread to other parts of the body.

Biopsy: To check if the tumor is CCS your doctor will do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope and do genetic tests to find out what kind of tumor it is. 

Getting the correct diagnosis is very important to get the right treatment.

How is clear cell sarcoma treated?

Treatment for each person will be unique. You should go to an expert in sarcoma treatment to decide the best approach for your tumor. You can contact MyPART for help finding experts near you.

Surgery: Surgery to remove the tumor and some healthy tissue around it is the best treatment for CCS. In some cases, an entire arm or leg may need to be amputated. If some cancer cells are left behind, there is a greater chance of the cancer coming back in the same spot. Or, it may spread to a different part of the body. 

Radiation therapy: Radiation therapy can be used before or after surgery if doctors think that surgery alone will not remove all the tumor cells. Even so, we don’t know if radiation therapy will help you live longer.

Chemotherapy:  When surgery is not possible or when the cancer has spread, chemotherapy can be used to treat CCS. But it does not seem to be an effective way to treat CCS. 

Does clear cell sarcoma run in families?

No, CCS does not run in families.

How does clear cell sarcoma form?

We know that in CCS, chromosomes (the structures in your cells that contain all your genes) break apart and are put back together in the wrong way. This can cause cells to not work right. In CCS, a gene called EWSR1 joins with a region called ATF1 creating a fusion gene called EWSR1/ATF1. This can also happen with the gene CREB1 (EWSR1/CREB1). Doctors will look for this change in chromosomes to confirm that your cancer is CCS. This gene fusion happens in almost all cases of CCS. So scientists are trying to figure out how this works so they can find and test new treatments.

What is the prognosis for someone with clear cell sarcoma?

The estimate of how a disease will affect you long-term is called prognosis. Every person is different and your prognosis will depend on many factors, such as: 

  • Where the tumor is in your body
  • If the cancer has spread to other parts of your body
  • How much of the tumor was taken out during surgery 

If you want information on your prognosis, it is important to talk to your doctor. Also, NCI has resources to help you understand cancer prognosis

Doctors estimate CCS survival rates by how groups of people with CCS have done in the past. Because there are so few CCS patients, these rates may not be very accurate. Studies estimate the 5-year survival rate of CCS is between 30% and 67%.

Prognosis for CCS is poor because it often spreads quickly to other parts of the body and often comes back after treatment. People tend to have a better prognosis when their CCS tumors are smaller than 2 inches and can be removed with surgery.