Osteosarcoma and Ewing sarcoma are bone cancers that primarily affect children, teens, and young adults. Symptoms they share include bone pain, stiffness, and swelling at the tumor site.

About 2% of childhood cancers are osteosarcoma, while about 1% of childhood cancers are Ewing sarcoma.

Ewing sarcoma most often affects children between the ages of 10 and 20. Osteosarcoma is more common in those between ages 10 and 30. Both cancers are rare in adults.

Both cancers are treated with chemotherapy, and surgery to remove the tumors is common. In both cases, survival odds are best when cancer is diagnosed in the early stages.

This article reviews the symptoms, causes, treatment, and outlook for each.

Both osteosarcoma and Ewing sarcoma are bone cancers that primarily affect children, teens, and young adults. Osteosarcoma is more common in teens and young adults. Ewing sarcoma is more common in children and teens.

Osteosarcoma tumors grow along the edge of long bones and are most commonly found in long bones of the knee and in the upper arm bones. Other osteosarcoma locations include the pelvis, shoulder, and skull.

Ewing tumors develop in the bone tissues and have distinctive round blue cells. They can be found in any bone, but are most common in the pelvis, thighs, ribs, and upper arms.

There are several symptoms that osteosarcoma and Ewing sarcoma share. These include bone pain, stiffness, and swelling around the tumor site.

Some symptoms set these cancers apart from each other. You can see a comparison in the table below.

Osteosarcoma symptomsEwing sarcoma symptoms
bone painbone pain
pain that comes and goes but gets worse with timeswelling and tenderness near the tumor site
a warm lump at the tumor sitefatigue
swelling and redness at the tumor sitefever
limited movement in the affected limbunintentional weight loss

Osteosarcoma and Ewing sarcoma have some overlapping risk factors. The primary shared risk factors are age and gender. Both tumors are slightly more common in boys, and both tumors are rare in adulthood, although the risk for osteosarcoma increases again for those over age 60.

Ethnicity is a risk factor that sets these cancers apart. Black and Hispanic children have a higher risk of osteosarcoma, while white children have a higher risk of Ewing sarcoma.

Osteosarcoma has some additional risk factors, including:

  • Height: Children who are considered tall for their age are at a greater risk.
  • Previous radiation: There is a link between previous radiation treatment to bones and a higher risk of osteosarcoma.
  • Noncancerous bone diseases: Certain bone diseases increase the risk of osteosarcoma.
  • Inherited cancer syndromes: Certain rare, inherited cancer syndromes increase the risk of osteosarcoma.

There are a variety of tests that can confirm a diagnosis of either osteosarcoma or Ewing sarcoma. Factors such as the difference in symptoms can help doctors determine what type of bone cancer a person has, but imaging and biopsies are the best ways to tell these cancers apart during diagnosis.

An MRI scan is one of the most important tests. An MRI can create images that show the differences in tumor location that can distinguish osteosarcoma from Ewing sarcoma.

Biopsies can see the difference in cancerous cells and can finalize the diagnosis.

Additional tests you might have during diagnosis include:

The treatment for osteosarcoma and Ewing sarcoma depends on several factors, including:

  • the stage and grade of the tumor
  • the tumor location
  • the person’s age
  • the person’s overall health

The first treatment for osteosarcoma is typically surgery to remove the tumor. Doctors will attempt to remove the tumor while preserving the affected limb when possible. However, sometimes limb removal is also needed.

Chemotherapy is also an important part of osteosarcoma treatment. It can help kill remaining cancer cells after surgical treatment.

Surgery can also be done to remove Ewing tumors, but it’s not typically the first step. Often, treatment for Ewing sarcoma starts with chemotherapy. This may be done in preparation for surgery or instead of surgery. A combination of chemotherapy and radiation therapy may follow surgery.

Outlooks for osteosarcoma and Ewing sarcoma are similar. The relative survival rates for both cancers depend on factors such as stage at diagnosis and response to treatment.

Survival rates in the table below are from the SEER database, which is maintained by the National Cancer Institute.

5-year relative survival rate for osteosarcoma5-year relative survival rate for Ewing sarcoma
Early stage tumor: 76%Early stage tumor: 82%
Regional cancer spread: 64%Regional cancer spread: 71%
Distant cancer spread: 24%Distant cancer spread: 39%
Overall survival rate: 59%Overall survival rate: 63%

A relative survival rate gives you an idea of how long someone with a specific condition may live after their diagnosis compared with someone without the condition. For example, a 5-year relative survival rate of 63% means that someone with that condition is 63% as likely to live for 5 years as someone without the condition.

It’s important to know that these numbers are based on data collected between 2012 and 2018. There have been improvements in cancer treatments in the past several years. It’s likely that current survival rates are higher. Additionally, outlooks can be highly individual and based on a variety of factors.

Osteosarcoma and Ewing sarcoma are similar tumors. They are both cancers that are more common in children, teens, and young adults. However, there are some key differences.

Osteosarcomas grow on the outside of bones, while Ewing sarcomas grow on bone tissues. Osteosarcomas are most often found around the knee. They can sometimes be found in the shoulder, upper arm, pelvis, and skull, while Ewing sarcoma is most often found in the pelvis, thighs, ribs, and upper arms.

Both cancers cause bone pain as a primary symptom, but Ewing sarcoma is more likely to also cause symptoms such as fatigue, fever, and weight loss.

The survival rates for both cancers are similar. People who are diagnosed in the early stages of either cancer have the best outlooks.