Ewing Sarcoma: High-Dose Chemotherapy and Stem Cell Transplant

What is a stem cell transplant?

For some advanced Ewing sarcomas or those that are no longer responding to other treatments, your child’s healthcare provider may suggest high doses of chemotherapy (chemo). This is done to try to kill the cancer cells. High-dose chemo can also destroy bone marrow. This is the soft tissue inside the bones where new blood cells are made. 

Stem cells are immature cells that are the starter cells for all types of body tissues. A stem cell transplant uses stem cells to replace bone marrow that’s been destroyed with high-dose chemo or radiation to the whole body. Healthy stem cells are then put in the body. These stem cells will grow and become new and healthy bone marrow cells. This can then make new blood cells. A stem cell transplant lets healthcare providers use higher doses of chemo than a person would normally be able to tolerate.

When might a stem cell transplant be used for Ewing sarcoma?

Experts are working to find out how helpful stem cell transplants are for Ewing sarcoma. Stem cell transplants aren’t a main treatment for Ewing sarcoma. If a stem cell transplant is used, it’s often as part of a clinical trial. Your child's healthcare provider may suggest one in certain cases. These can include the following:

• The cancer is no longer responding to standard treatment. Or it comes back after treatment.

• The cancer has spread to other parts of the body. Or it has other features that mean it will likely be hard to treat with standard approaches.

Types of stem cell transplants

There are 2 kinds of stem cell transplants. They include:

• Autologous transplant. This means the stem cells are collected from your child's own body and preserved. This is done before he or she gets chemo.

• Allogeneic transplant. This means the stem cells come from another person whose cell type is almost exactly like your child’s. This may be a brother or sister.

For Ewing sarcoma, autologous transplants are used.

How stem cells are collected 

From the blood

This is the most common source of stem cells for a transplant. Your child may get an injection of a growth factor medicine for several days. This medicine helps stimulate stem-cells to be made. The process for collecting stem cells from the blood is called apheresis. It’s a lot like giving blood, but it takes longer. A thin, flexible tube (catheter) is used to get blood from your child's vein. The blood goes to a cell separation device to remove the stem cells. The stem cells are then frozen until they’re needed later. Then the extra blood is returned to your child. This process may need to be done more than once to collect the right amount of cells.

From the bone marrow

Stem cells may also be taken from the bone marrow. This process is done while your child is asleep with general anesthesia. A healthcare provider makes several punctures in the pelvic or hip bone to remove marrow. Soreness in the hip bone may last for several days. These stem cells are filtered and frozen until they’re needed. This approach to collecting stem cells is used less often than in the past.

Having the transplant

• Your child will likely be admitted to the hospital the day before the transplant. The healthcare provider will go over how to keep your child's gown sterile, how to prepare food after the transplant, and other ways to help your child avoid germs. This is needed to lower your child's risk of infections.

• After chemo or radiation is done, your child will receive the stored stem cells through a needle in his or her arm that’s attached to a tube. This is like a blood transfusion.

• You then have to wait for your child's new stem cells to start multiplying. The child may have to stay in isolation away from people to avoid getting an infection. Once part of the white blood cell count (absolute neutrophil count or ANC) reaches a safe level, your child can come out of isolation and then eventually go home. This may happen within several weeks or it may take longer.

• Your child will need to have their blood drawn often to check their blood cell counts for the next several weeks. This can be done on an outpatient basis. 

Possible short-term side effects

Most of the short-term side effects of a stem cell transplant are from the high doses of chemo or radiation. These should go away as your child recovers from the transplant. Common side effects can include:

• Infections

• Low blood cell counts

• Bleeding

• Low blood pressure

• Shortness of breath

• Chest pain or tightness

• Coughing

• Fever or chills

• Hair loss

• Nausea

• Vomiting

• Mouth sores

• Loss of appetite

• Diarrhea

• Fatigue

• Weakness

Possible long-term side effects

Some side effects of a stem cell transplant may be long-lasting or show up years later. These can include:

• Bone pain. This is caused from damage due to lack of blood supply (aseptic necrosis).

• Growth of another cancer

• Lung problems

• Damage to other organs. These can include the heart, kidneys, or liver.

• Lack of menstrual periods. This may mean ovary damage and cause infertility.

• Vision problems. This can be caused by damage to the lens of the eye.

• Weight gain. This may be a sign of thyroid gland damage.

Talking with your child's healthcare provider

Before your child has a stem cell transplant, it's important to discuss this procedure with your child's healthcare provider to make sure you understand the possible risks and benefits. A stem cell transplant is a complex procedure. It’s only done by healthcare provider with special training. If you decide this is the best option for your child, it's important to have it done at a hospital that specializes in stem cell transplants, such as a major cancer center. The procedure is also expensive. Make sure to check with your insurance provider to see how much of it will be covered.