Ewing Sarcoma: High-Dose Chemotherapy and Stem Cell Transplant
What is a stem cell transplant?
A stem cell transplant used very high doses of chemotherapy (chemo) to try to kill
all the cancer cells in the body. This high-dose chemo also destroys the bone marrow.
This is the soft, spongy tissue inside the bones where new blood cells are made.
Bone marrow (hematopoietic) stem cells are immature cells that are the starter cells
for all types of blood cells. After the high-dose chemo, stem cells are "transplanted"
or put into the body to replace the bone marrow that’s been destroyed by the chemo.
The healthy stem cells that are put in the body will grow and become new, healthy
bone marrow cells. This bone marrow can then make new blood cells. A stem cell transplant
lets healthcare providers use much higher doses of chemo than a person would normally
be able to get.
When might a stem cell transplant be used for Ewing sarcoma?
High-dose chemo followed by a stem cell transplant might be used to treat Ewing sarcoma
when:
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It has spread from where it first started to other parts of the body
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It's no longer responding to other treatments
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It comes back after treatment
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. And when a stem cell
transplant is done, it’s often as part of a clinical trial.
Types of stem cell transplants
There are two kinds of stem cell transplants:
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Autologous transplant. This means the stem cells are collected from your body or your child's body and saved.
This is done before the chemo is given.
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Allogeneic transplant. This means the stem cells come from another person (a donor). This may be a brother
or sister. Or it may also be from someone not related to you or your child.
Autologous transplants are almost always used for Ewing sarcoma.
How stem cells are collected
From the blood
This is the most common source of stem cells for a transplant. You or your child may
get an injection of a growth factor medicine for several days. This medicine helps
force the bone marrow to make stem cells.
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 (called a catheter)
is put in a vein and used to take out blood. The blood goes into a cell separation
device where the stem cells are removed from it. Then the rest of the blood is returned
to you or your child. The removed stem cells are then frozen until they’re needed
later. This process may need to be done more than once to collect enough cells.
From the bone marrow
Stem cells may also be taken from the bone marrow. This process is done while medicines
are used to make you or your child sleep and not feel pain (general anesthesia). A
thick needle is put into the pelvic or hip bone and a syringe is used to pull out
marrow. Afterwards, the hip bone may be sore for several days. The bone marrow is
filtered and the stem cells are frozen until they’re needed. Stem cells aren't often
collected this way today.
Having the transplant
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You or your child will likely be admitted to the hospital the day before the transplant.
The healthcare provider will go over things you can do to help you or your child stay
away from germs. This is needed because you or your child will be at a high risk for
infections for a while.
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After chemo or radiation is done, you or your child will get the stored stem cells.
They're put right into the blood through a vein. It's a lot like getting a blood transfusion.
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You then have to wait for your new stem cells or your child's new stem cells to start
growing. You or your child may have to stay in isolation and away from people in order
to keep from getting an infection. Once part of the white blood cell count (absolute
neutrophil count or ANC) reaches a safe level, you or your child can come out of isolation
and then, in time, go home. This may happen within a few weeks. But sometimes it takes
longer.
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You or your child will need to have blood tests done to check blood cell counts for
the next few months. This can be done as an outpatient. That means you or your child
can go home the same day.
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. Many of them can be treated, and some can be prevented. They
should go away over time as you or your child recovers from the transplant. Common
side effects can include:
Possible long-term side effects
Some side effects of a stem cell transplant may be long-lasting or not show up until
years later. These can include:
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Bone pain. This is caused from bone damage because of too little blood (called aseptic
necrosis).
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Growth of another cancer
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Lung problems
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Damage to other organs. These can include the heart, kidneys, or liver.
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Lack of menstrual periods. This may mean ovary damage.
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Infertility (not able to have children)
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Vision problems. This can be caused by damage to the lens of the eye.
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Weight gain. This may be a sign of thyroid gland damage.
Talking with your or your child's healthcare provider
Before you or your child has a stem cell transplant, it's important to discuss the
details of this procedure with your or your child's healthcare team to make sure you
understand the possible risks and benefits. A stem cell transplant is a complex procedure
that can cause life-threatening problems. It’s only done by healthcare provider with
special training. If you decide this is the best choice for you or 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 also costs a lot. Check with your insurance
provider to see how much of it will be covered.