Prognostic Factors and Survival Rates for Ewing Sarcoma

Prognostic factors are features that may predict who or which tumors will respond best to treatment. These tools can’t tell you for sure whether treatment will be successful, but they may help give you a better understanding of how likely this is.

Survival rates are a way to measure how many people survive a certain type of cancer over time. They can’t tell you exactly what will happen with any one person, but they may be able to help you better understand what to expect.

Prognostic factors for Ewing sarcoma

In people with cancer, certain factors that can affect outlook (prognosis) are called prognostic factors. They help doctors anticipate how a cancer will respond to different treatments. Factors that may be associated with outlook in Ewing sarcoma include:

• Metastases: Tumors that have spread to distant areas of the body can be more difficult to treat. About 1 in 5 Ewing sarcomas have already metastasized at diagnosis.
• Tumor location and size: Tumors in the bones of the extremities (like the arms or legs) tend to respond better to treatment than tumors of the trunk (spine, shoulder, chest or pelvis). Smaller tumors are also often easier to treat than larger tumors.
• Response to treatment: When Ewing sarcoma tumors are removed by surgeons, specialized doctors (pathologists) look at the tumor under the microscope. When tumors cells die after early chemotherapy, the cancer is responding to the treatment and is less likely to come back after treatment is finished.

Survival rates in Ewing sarcoma

To estimate survival rates, doctors must look at people who were treated at least 5 years ago. Changes in treatment since then may result in a better outlook for people diagnosed with Ewing sarcoma today.

These statistics can be confusing and might raise more questions for you. Ask your doctor how these numbers might apply to you.

What is a 5-year survival rate?

The 5-year survival rate refers to the percentage of people who live at least 5 years after their cancer is diagnosed. Of course, people may live much longer than 5 years.

What is a 5-year relative survival rate?

Relative survival rates are a more accurate way to estimate the effect of cancer on survival. These rates compare people with the same type and stage of cancer to people in the overall population.

For example, if the 5-year relative survival rate for a specific type and stage of cancer is 80%, it means that on average, people who have cancer are about 80% as likely to live for at least 5 years after being diagnosed, compared to people who don’t have that cancer.

Where do these numbers come from?

The American Cancer Society relies on information from the Surveillance, Epidemiology, and End Results (SEER) database, maintained by the National Cancer Institute (NCI), to provide survival statistics for different types of cancer.

The SEER database tracks 5-year relative survival rates for Ewing sarcomas in the United States, based on how far the cancer has spread. The SEER database, however, does not group cancers by MSTS or AJCC TNM stages. Instead, it groups cancers into localized, regional, and distant stages:

• Localized: There is no sign that the cancer has spread outside the bone (or to other areas) where it started.
• Regional: The cancer has spread outside the bone (or to other areas) and into nearby structures, or it has reached nearby lymph nodes.
• Distant: The cancer has spread to distant areas of the body, such as to the lungs or to bones in other parts of the body.

5-year relative survival rates for Ewing sarcoma

These numbers are based on people diagnosed with Ewing tumors between 2015 and 2021.

SEER* stage	5-year relative survival rate
Localized	81%
Regional	77%
Distant	41%
All SEER stages combined	65%

*SEER = Surveillance, Epidemiology, and End Results

Understanding the numbers

These numbers apply only to the stage of the cancer when it is first diagnosed. They do not apply later on if the cancer grows, spreads, or comes back after treatment.

Keep in mind that survival rates are estimates. They can’t predict what will happen in any one person’s case. Other factors, such as a person’s age and overall health, which area the cancer started in, and how well the cancer responds to treatment can affect your outlook. Treatment also improves over time, and these numbers are based on people who were diagnosed and treated at least 5 years earlier.