Epithelioid Sarcoma

Epithelioid sarcoma (ES) is a rare subtype of soft tissue sarcoma. It usually starts as a lump in the connective tissues of your forearms, hands, fingers, lower legs or feet. But it can also appear in other areas of your body.

Epithelioid sarcoma grows slowly. Even so — it’s still considered aggressive. This is because it often grows deeply into tissue and can spread. About half the time, it comes back after surgery removes it.

ES is an extremely rare form of sarcoma. And sarcomas, in general, are one of the rarest types of cancer. So, it’s important not to assume that every new lump is ES.

But if you are diagnosed, it’s a good idea to seek care in a place that specializes in treating rare sarcomas. Expertise is always important when it comes to getting the best results. This is especially true for rare cancers.

Types of epithelioid sarcoma

There are two types:

• Distal type ES (most common) typically affects teens and young adults. Tumors start in your forearms, hands, fingers, lower legs and feet.
• Proximal type ES mainly affects adults. It forms in areas closer to the center of your body. This includes your head, neck, chest, abdomen and genitals.

Symptoms of epithelioid sarcoma

You may have ES for months (or even years) before noticing any symptoms. This is because these tumors often grow into tissue, where you can’t see them. As the tumor gets bigger, you may notice these epithelioid sarcoma symptoms:

• A new, hard lump or area of swelling beneath your skin
• An existing lump that gets bigger
• Open wounds on your skin above the lump
• Pain (if it puts pressure on muscles or nerves)

Epithelioid sarcoma causes

Healthcare providers aren’t sure what causes epithelioid sarcoma. But often, it’s related to an abnormality of the SMARCB1 gene. SMARCB1 is a tumor suppressor gene. It contains instructions that tell your body how to prevent tumors.

With ES, this gene changes (mutates). The mutation happens at some point during your lifetime. So, it’s not something you’re born with.

Errors in your SMARCB1 gene make it easier for tumors to form.

Risk factors

Anyone can get ES. But most people diagnosed are young adults, between ages 20 and 40. You’re slightly more likely to have it if you’re male or if you’ve had radiation therapy for other cancers in the past.

How doctors diagnose epithelioid sarcoma

Your healthcare provider will do several tests to diagnose ES, which may include:

• A physical exam: Your provider will do a whole-body skin check to look for lumps. This helps rule out skin conditions that may look like ES.
• Imaging tests: An MRI helps your provider find the tumor inside your body. CT scans and PET scans show if the cancer has spread. ES may spread to your lymph nodes, lungs and bones.
• Biopsy: This is the only way for providers to confirm an ES diagnosis. Your provider will test the lump for cancer cells. They may also test your lymph nodes, since ES commonly spreads there.

Staging epithelioid sarcoma

Cancer staging allows your healthcare provider to determine how advanced the cancer is. They assign numbers from 1 (I) to 4 (IV) based on things like tumor size, location and whether it’s spread. Stage I is least advanced, or early-stage cancer. Stage IV is most advanced, or cancer that’s spread.

Your provider may use words like “localized” to describe your cancer stage. Localized ES is easier to treat because it’s only in one area, so it’s easier to remove with surgery. As a result, localized ES often responds better to treatment than ES that’s spread.

How is epithelioid sarcoma treated?

ES treatments include:

• Surgery: Surgery is the most common treatment for tumors that haven’t spread. Your surgeon will work to remove all the cancer while preserving your limb function. They may also remove nearby lymph nodes with cancer cells.
• Radiation therapy: You may need radiation therapy after surgery to kill any remaining cancer cells. You may get it before surgery to shrink large tumors, so they’re easier to remove.
• Chemotherapy: You may need chemotherapy if the cancer has spread. ES usually responds to chemotherapy in the short term. Over time, chemo often becomes less effective.
• Targeted therapy: This treatment interferes with proteins that promote tumor growth. Tazemetostat is a common drug that treats advanced ES.

If treatments aren’t helping enough, your provider may suggest taking part in a clinical trial. Clinical trials test the safety and effectiveness of new treatments. For example, current clinical trials are testing immunotherapy as a possible ES treatment.

When should I see my healthcare provider?

Not every lump or bump on your body is worth worrying over. Usually, bumps aren’t cancer. But anytime you notice an abnormal lump on your body that’s growing, you should see a healthcare provider.

What can I expect if I have epithelioid sarcoma?

Epithelioid sarcoma is treatable, especially in the early stages. Completely removing the tumor can cure it. If your healthcare provider can’t completely remove a tumor, they’ll recommend treatments to manage your condition.

Even if ES goes into remission (no signs or symptoms of cancer), you’ll need regular checkups to see if it’s returned. In about half of people, tumors grow back. Sometimes, it shows up again in the same location. Other times, ES appears in a new area. When it recurs, it usually does so within the first few years after surgery. But there are cases where cancer has come back 20 years later.

What is the survival rate of epithelioid sarcoma?

The five-year survival rate for epithelioid sarcoma ranges from 50%to 75%. This means that in the past, up to 3 out of 4 people diagnosed were alive five years later. But life expectancy varies based on cancer stage. For example, about half of people with ES that has spread survive the first year.

Factors related to better outcomes include:

• Distal type ES
• Early cancer stage
• Small tumors
• Tumors that are removable with surgery
• Young age at diagnosis (children with ES often have better outcomes)

Ask your healthcare provider to explain how these things influence your prognosis (outlook). Survival rates provide a snapshot of the past. But your provider is your best source for explaining what matters most in terms of your future.

Is there anything I can do to feel better?

Living with cancer — especially a rare one — can feel isolating. Given how often ES comes back, you may feel unable to relax even if surgery removed all of the tumor.

You can cope by having honest talks with your provider about what results you can expect from treatment. Finding a support network is more important than ever. You’re not alone in living with a rare cancer. Your provider can recommend resources to help you connect with others.