Chemotherapy for Ewing tumors
Chemotherapy (chemo) is the use of anti-cancer drugs delivered through a vein (IV) or, rarely, by mouth in the form of pills. These drugs enter the bloodstream and affect cancer cells in all parts of the body, which makes this treatment useful for cancers that are likely to have spread.
Chemo is an important part of treatment for just about all patients with Ewing tumors. It is typically the first treatment given, followed by surgery and/or radiation therapy. More chemo is often given after the surgery and/or radiation is done.
As noted in the section “How are Ewing tumors staged?”, even patients with localized Ewing tumors, who have no obvious cancer spread in bone marrow samples or on imaging tests, are likely to have areas of cancer spread that are too small to be found with these tests. If these patients do not get chemotherapy, these small metastases would eventually develop into larger tumors.
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 patients with Ewing tumors.
In the United States, the most common regimen alternates between 2 combinations of drugs given every 2 to 3 weeks (VAdriaC alternating with IE). The first set of drugs includes vincristine, doxorubicin (Adriamycin), and cyclophosphamide. After the patient recovers from the effects of these drugs, another combination of drugs, ifosfamide and etoposide, is given. Some doctors may use slightly different combinations of drugs.
Chemotherapy is given for at least 12 weeks before surgery or radiation and is then given 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, these same drugs may be given at higher doses.
Soon after the Ewing tumor is diagnosed (but before starting chemo), the doctor may suggest putting 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). The catheter is inserted surgically while the patient is under general anesthesia (in a deep sleep). One end of the catheter stays in the vein, while the other end lies just under or outside the skin. This lets the healthcare team give chemo and other drugs and to draw blood samples without having to stick needles into the veins each time. The catheter usually stays in place for several months, and can make having chemo less painful. If such a device is used in your child, the health care team will teach you how to care for it to reduce the risk of problems such as infections.
Possible side effects of chemotherapy
Chemo drugs attack cells that are dividing quickly, which is why they work against cancer cells. But other cells in the body, such as those in the bone marrow (where new blood cells are made), the lining of the mouth and intestines, and the hair follicles, also divide quickly. These cells are also likely to be affected by chemo, which can lead to side effects.
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.
The side effects of chemo depend on the type and dose of drugs given and the length of time they are taken.
General side effects: Side effects common to many chemo drugs include:
- Hair loss
- Mouth sores
- Loss of appetite
- Nausea and vomiting
- 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 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 can damage the heart. This risk goes up as the total dose of the drug goes up. Doctors try to limit this risk as much as possible by not giving more than the recommended doses of doxorubicin and by checking the heart with a test called an echocardiogram during treatment.
Vincristine can damage nerves. 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 be long lasting in some people.
Some chemo drugs can affect your (child’s) ability to have children later in life. Talk to your (or your child’s) cancer care team about the risks of infertility with treatment, and ask if there are options for preserving fertility, such as sperm banking or ovarian tissue banking.
Some drugs used to treat Ewing tumors, such as etoposide, can increase the risk of later developing a cancer of white blood cells known as acute myeloid leukemia. Fortunately, this doesn’t happen often.
For more on the possible late or long-term side effects of chemo, including infertility and second cancers, see “What happens after treatment for Ewing tumors?”
Tests to check for chemo side effects: Before each treatment, your (child’s) doctor will check lab test results 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) includes counts of white blood cells, red blood cells, and blood platelets. Chemo can lower the numbers of these blood cells, so blood counts 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 earlier 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 the kidneys and liver.
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.
Last Medical Review: 09/18/2014
Last Revised: 02/04/2016