What is Ewing sarcoma?
Ewing Sarcoma is a rare type of cancer that occurs in the bones or in the soft tissue around the bones.
Ewing sarcoma most often begins in the bones of the legs and pelvis, but it can occur in any bone. Less commonly, it begins in the soft tissues of the chest, abdomen, extremities, or other locations.
Ewing sarcoma is most common in children and teens, but it can occur at any age.
Major advances in the treatment of Ewing’s sarcoma have helped improve the outlook for people with this cancer. After completion of treatment, lifelong follow-up is recommended to observe possible late effects of severe chemotherapy and radiation.
Types of Ewing Sarcoma
There are numerous kinds of Ewing sarcoma, including Ewing sarcoma of bone, Ewing’s sarcoma extraosseous, peripheral primitive neuroectodermal tumor (pPNET), and Askin’s tumor. These tumours are considered related because they have similar genetic causes.
Symptoms of Ewing sarcoma
The signs and symptoms of Ewing sarcoma include:
- Pain, swelling, or tenderness near the affected area
- Unexplained tiredness
- Fever with no known cause
- Lose weight without trying
Causes of Ewing sarcoma
It is not clear what causes Ewing sarcoma.
Physicians know that Ewing sarcoma starts when a cell develops changes in its DNA. A cell’s DNA contains the instructions that tell the cell what to do. The changes tell the cell to multiply rapidly and to continue living when healthy cells would normally die. The result is a mass (tumour) of abnormal cells that can invade and end healthy body tissue. Abnormal cells can separate and spread (metastasize) throughout the body.
In Ewing sarcoma, DNA changes most often affect a gene called EWSR1. If your doctor suspects that you have Ewing sarcoma, your cancer cells may be tested for changes in this gene.
- Your age: Ewing sarcoma can occur at any age, but it is more likely to occur in children and adolescents.
- Your ancestry: Ewing sarcoma is more common in people of European descent. It is much less common in people of African and East Asian descent.
- Cancer that spreads (metastasizes): Ewing’s sarcoma can spread from where it started to other areas, making treatment and recovery difficult. Ewing’s sarcoma most often spreads to the lungs and other bones.
- Long-term side effects of treatment: The aggressive treatments needed to control Ewing sarcoma can cause substantial side effects, both short and long term. Your healthcare team can help you monitor the side effects that occur during treatment and provide you with a list of side effects to watch for in the years after treatment.
Diagnosis of Ewing sarcoma
The diagnosis usually begins with a physical exam to better understand the symptoms that you or your child may be experiencing. Based on those findings, other tests and procedures may be recommended.
Imaging tests help your physician examine your bone symptoms, look for cancer, and look for signs that cancer has spread.
Imaging tests may include:
- Computed tomography (CT)
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET)
- Bone scan
Removing a sample of cells for analysis (biopsy). A biopsy process is used to collect a sample of suspicious cells for research laboratory testing. The tests can show if the cells are cancerous and what type of cancer you have.
The types of biopsy procedures used to diagnose Ewing sarcoma include:
- Needle biopsy: The doctor inserts a fine needle through the skin and guides it to the tumor. The needle is used to eliminate small pieces of tissue from the tumor.
- Surgical biopsy: The doctor makes an incision through the skin and removes the entire tumor (excisional biopsy) or part of the tumor (incisional biopsy).
Determining the type of biopsy need the details of, how it should be performed and requires careful planning on the part of the medical team. Doctors must perform the biopsy in a way that does not interfere with future surgery to remove cancer. For this reason, ask your doctor for a referral to a team of experts with extensive experience treating Ewing sarcoma before your biopsy.
Cancer cell testing for genetic mutations
A sample of your cancer cells will be tested in the laboratory to determine what DNA changes are present in the cells. These cells often have changes in the EWSR1 gene. Very often, the EWSR1 gene fuses with another gene called FLI1, creating a new gene called EWS-FLI1. Testing cancer cells for these genetic changes can help confirm your diagnosis and give your doctor clues as to how aggressive your disease is.
Ewing sarcoma treatment
Treatment for Ewing’s sarcoma usually begins with chemotherapy. Surgery to remove cancer usually follows. In certain situations, other treatments may be used, including radiation therapy.
Chemotherapy uses powerful drugs to kill cancer cells. Chemotherapy treatment usually combines two or more drugs that can be given as an infusion into a vein (IV), as a pill, or by both methods. Treatment for Ewing’s sarcoma usually begins with chemotherapy. Medications can shrink the tumor and make it easier to remove cancer with surgery or target it with radiation therapy.
After surgery or radiation therapy, chemotherapy treatments can continue to kill any cancer cells that may remain. For advanced cancer that has spread to other areas of the body, chemotherapy can help relieve pain and slow the growth of cancer.
The goal of surgery is to kill all cancer cells. But the planning of the operation also takes into account how it will affect your ability to carry out your daily life. Surgery for Ewing sarcoma may involve the removal of a small piece of bone or the removal of an entire limb. Whether surgeons can eliminate all of cancer without removing the entire limb rest on several factors, such as the size and locality of the tumor and whether it shrinks after chemotherapy.
Radiation therapy usages high-energy beams, such as x-rays and protons, to kill cancer cells. During radiation therapy, beams of energy are sent from a machine that moves around you as you lie on a table. The rays are carefully aimed at the area of Ewing’s sarcoma to reduce the risk of damage to surrounding healthy cells.
Radiation therapy may be recommended after surgery to kill any remaining cancer cells. It can also be used instead of surgery if Ewing’s sarcoma is in a part of the body where surgery is not possible or would lead to unacceptable functional results (such as loss of bowel or bladder function). For advanced Ewing sarcomas, radiation therapy can deliberate the growth of cancer and help dismiss the pain.
While it is always good to maintain a healthy weight and stop smoking or using tobacco, there are currently no known lifestyle changes that can prevent Ewing sarcoma.