What is Clear Cell Sarcoma?
Clear cell sarcoma (CCS) is a rare type of soft tissue cancer. These tumors are most commonly found in the arms, legs, feet, and hands but can also develop in the torso, including the stomach and intestines, as well as in the genitals and head. CCS gets its name because the tumor cells appear clear under a microscope.
How Common is CCS?
CCS is extremely rare, accounting for only 1% of all sarcoma cases. It most often affects teenagers and young adults, with an average age at diagnosis of 25. Due to its rarity, exact prevalence rates are unknown.
How is Clear Cell Sarcoma Diagnosed?
Diagnosing CCS can be challenging because it shares microscopic features with other cancers, such as malignant melanoma of soft parts. Due to its similarities to the skin cancer melanoma, clear cell sarcoma requires careful evaluation by an experienced medical team familiar with identifying such tumors. In the past, CCS was even referred to as “malignant melanoma of soft parts” because of these shared features. However, CCS has unique genetic markers that distinguish it from other cancers.
- Imaging Tests: MRI and CT scans are used to locate the tumor, measure its size, and check for spread.
- Biopsy: A small sample of the tumor is taken and studied by a pathologist. Genetic testing is often done to identify the specific gene fusions (EWSR1/ATF1 or EWSR1/CREB1) common in CCS.
Symptoms may not appear in the early stages but can include:
- A lump under the skin, sometimes painful
- Unexplained weight loss
- Fatigue
- Night sweats
How is CCS Treated?
Treatment varies depending on the individual and the tumor’s characteristics. It is critical to consult a sarcoma specialist for the best approach.
- Surgery: The primary treatment for CCS, aiming to remove the tumor and surrounding tissue. In rare cases, amputation may be required. Incomplete removal increases the risk of recurrence or spread.
- Radiation Therapy: Often used before or after surgery to target any remaining cancer cells. Its effectiveness in improving survival is uncertain.
- Chemotherapy: Used when surgery isn’t an option or when the cancer has spread. However, chemotherapy has limited effectiveness in treating CCS. Discover how chemotherapy works to treat cancer, its role in combination therapies, and what to expect during treatment. Learn more in our detailed article.
Does Clear Cell Sarcoma Run in Families?
No, CCS is not hereditary and does not run in families.
What Causes Clear Cell Sarcoma?
CCS develops due to specific genetic changes in cells and in most cases, the EWSR1 gene fuses with ATF1 or CREB1, forming abnormal fusion genes that disrupt cell function. Researchers are studying these genetic changes to develop targeted therapies.
What is the Prognosis for Clear Cell Sarcoma?
The prognosis depends on factors such as tumor size, location, whether the cancer has spread, and how much of the tumor is removed during surgery.
- Survival Rates: The 5-year survival rate for CCS is estimated at 30%–67%.
- Factors for Better Prognosis: Smaller tumors (under 2 inches) and successful complete removal with surgery improve outcomes.
Unfortunately, CCS tends to spread quickly and recur after treatment, making long-term outcomes challenging.
Resources:
https://www.pennmedicine.org/cancer/types-of-cancer/sarcoma/types-of-sarcoma/soft-tissue-sarcoma/clear-cell-sarcoma
https://www.cancer.gov/pediatric-adult-rare-tumor/rare-tumors/rare-soft-tissue-tumors/clear-cell-sarcoma#:~:text=What%20is%20clear%20cell%20sarcoma,in%20the%20genitals%20and%20head.
