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Chemotherapy (chemo) is the use of drugs to treat cancer. The drugs are usually given into a vein (IV) and can affect cancer cells in all parts of the body, which makes this treatment useful for cancers that are likely to have spread.

When is chemo used for Ewing tumors?

Chemo is an important part of treatment for almost all patients with Ewing tumors (Ewing sarcomas). It is typically the first treatment given, followed by surgery and/or radiation therapy. More chemo is often given after surgery and/or radiation.

As noted in Ewing Tumor Stages, even patients with localized Ewing tumors, who have no obvious cancer spread shown on imaging tests or in bone marrow biopsy samples, are likely to have very small areas of cancer spread (micrometastases). If chemotherapy isn't given, these small metastases eventually would develop into larger tumors.

How is chemo given?

Doctors give chemo in cycles, with a period of treatment (often a few days in a row) followed by a rest period to give the body time to recover. A combination of several chemo drugs is used to treat Ewing tumors.

In the United States, the most common chemo regimen is known as VDC/IE (or VAC/IE). It alternates between 2 combinations of drugs, given every 2 to 3 weeks:

• The first drug combination includes vincristine, doxorubicin (Adriamycin), and cyclophosphamide.
• The second set of drugs includes a combination of ifosfamide and etoposide.

Some doctors may use slightly different drug combinations. These often include many of the same chemo drugs listed above, although other drugs might be used as well (especially if the cancer comes back after treatment).

Most patients will get chemo for at least 9 weeks before surgery or radiation, and then will get more chemo afterward as well. Usually a total of about 14 to 15 cycles of chemo are given, which can take from about 6 months to close to a year to complete, depending on the schedule. If the tumor has spread to other parts of the body, these same drugs may be given at higher doses.

Soon after the Ewing tumor is diagnosed (but before starting chemo), the doctor may suggest surgery to put a catheter (a thin, soft tube) into a large vein in the patient’s chest. This is sometimes called a venous access device (VAD) or central venous catheter (CVC). One end of the catheter stays in the vein, while the other end lies just under or outside the skin. The catheter usually stays in place for several months, letting the health care team give drugs and draw blood samples without having to stick needles into the veins each time. If you or your child gets such a device, the health care team will teach you how to care for it to reduce the risk of problems such as infections.

Side effects of chemo

When chemo drugs affect cells in the body other than cancer cells, it can lead to side effects. The side effects depend on the type and doses of drugs, and the length of time they are given.

Children tend to have less severe side effects from chemo than adults and often recover from side effects more quickly. This is why doctors can often give them higher doses of chemo to kill the tumor.

General side effects of chemo

Common side effects of many chemo drugs include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Diarrhea

Chemo can damage the bone marrow, where new blood cells are made. This can lead to low blood cell counts, which can result in:

• Increased chance of infections (from having too few white blood cells)
• Easy bruising or bleeding (from having too few blood platelets)
• Fatigue (from having too few red blood cells)

Most of these side effects tend to go away after treatment is finished. There are often ways to lessen them. For example, drugs can be given to help prevent or reduce nausea and vomiting, or to help get blood cell counts back to normal levels. Be sure to discuss any questions you have about side effects with the cancer care team.

Side effects of certain chemo drugs

Along with the effects listed above, certain chemo drugs can have specific side effects:

• Cyclophosphamide and ifosfamide can damage the bladder, which can cause blood in the urine. The risk of this happening can be lowered by giving the drugs with plenty of fluids and with a drug called mesna, which helps protect the bladder.
• Doxorubicin (Adriamycin) can damage the heart. This risk goes up with the total dose of the drug, so doctors are careful to limit the total dose. The doctor might order a heart function test (such as an echocardiogram) before and during treatment to see if this drug is affecting the heart. A drug called dexrazoxane may be given along with the chemo to help lessen the possible damage.
• Vincristine can cause nerve damage (neuropathy). Some patients may notice tingling and numbness, particularly in the hands and feet. This often goes away or gets better once treatment is stopped, but it may last a long time in some people.
• Etoposide can increase the risk of developing leukemia later on, although this is not common.

Some chemo drugs can affect your (child’s) ability to have children (fertility) later in life. Talk to the cancer care team about the possible effects of treatment on fertility, and ask if there are options for preserving fertility, such as sperm banking or ovarian tissue banking.

For more on the possible late or long-term side effects of chemo, including infertility and second cancers, see Living as a Ewing Tumor Survivor. 

Tests to check for chemo side effects: Before each treatment, lab tests will be done to be sure the liver, kidney, and bone marrow are working well. If not, chemo may need to be delayed or the doses reduced.

• The complete blood count (CBC) checks levels of white blood cells, red blood cells, and blood platelets. These will be watched closely during and after chemo. The white blood cells and platelets usually reach their lowest point about 2 weeks after chemo is given, though this can occur sooner with high-dose regimens.
• Blood chemistry tests measure certain chemicals in the blood that tell doctors how well the liver and the kidneys are working. Some chemo drugs can damage these organs.
• If doxorubicin (Adriamycin) is to be given, tests such as an echocardiogram (an ultrasound of the heart) may be done to check heart function before and during treatment.