Ewing Sarcoma: Introduction

What is cancer?

Cancer is when cells in the body change and grow out of control. Your body is made up of tiny building blocks called cells. Normal cells grow when your body needs them, and die when your body does not need them any longer.

Cancer is made up of abnormal cells that grow even though your body doesn't need them. In most cancers, the abnormal cells grow to form a lump or mass called a tumor. If cancer cells are in the body long enough, they can grow into (invade) nearby areas. They can even spread to other parts of the body (metastasis).

What is Ewing sarcoma?

Ewing sarcoma is a type of cancer that tends to start in the bone. This type of sarcoma is named after James Ewing, MD. He first spotted it in 1921. He noticed that the cells of what came to be called Ewing sarcoma looked different under the microscope than the cells of other bone tumors, such as osteosarcomas. Dr. Ewing also found that this type of tumor was more likely to respond to radiation treatment than other bone cancers.

Experts later found the same type of tumor in soft tissues. They named it extraosseous Ewing tumor (EOE). This means it’s not found in the bone. Another similar cancer is called peripheral primitive neuroectodermal tumor (PPNET). 

These tumors are now all referred to as the Ewing family of tumors (EFT) or just Ewing tumors. They are all treated in similar ways.

Studies of Ewing tumors have shown that they’re all caused by similar changes in the chromosomes inside the tumor cells. These changes are only found in the tumor cells. They are not genetic changes that get passed on from generation to generation. This means that a parent’s genes did not cause his or her child to get cancer. It isn’t known why these changes happen.

How Ewing sarcoma starts and grows

Most Ewing tumors start in the bones. The most common places for them to start include the following:

• Bones in the chest wall. These include the ribs or shoulder blade.

• Hip bones

• Leg bones

These tumors can start in other bones as well. Extraosseous Ewing tumors can start almost anywhere in the body.

Ewing tumors can grow into nearby tissues such. These include the muscles or tendons. The cancer cells can also spread to other parts of the body. This can often happen quickly. In fact, even if it looks like the cancer is still only where it started based on imaging tests, healthcare providers have to assume that some cancer cells may have reached other parts of the body. This is why chemotherapy is an important part of treatment for Ewing tumors. (Chemotherapy can reach all parts of the body.)

Talk with your healthcare provider

If you have questions about Ewing sarcoma, talk with your healthcare provider. He or she can help you understand more about this cancer.