Chemotherapy for neuroblastoma

Chemotherapy (chemo) uses anti-cancer drugs, which are usually given into a vein. The drugs enter the bloodstream and travel throughout the body to reach and destroy cancer cells. This makes chemo useful for treating neuroblastoma that has spread to the lymph nodes, bone marrow, liver, lungs, or other organs.

Some children with neuroblastoma are treated with chemotherapy either before surgery (neoadjuvant chemotherapy) or after surgery (adjuvant chemotherapy). In other cases, especially when the cancer has spread too far to be completely removed by surgery, chemotherapy is the main treatment.

Most children with neuroblastoma will need to have chemotherapy with a combination of drugs. The main drugs used to treat neuroblastoma include:

• Cyclophosphamide or ifosfamide
• Cisplatin or carboplatin
• Vincristine
• Doxorubicin (Adriamycin)
• Etoposide
• Topotecan
• Busulfan and melphalan (sometimes used during stem cell transplant)

The most common combination of drugs to treat neuroblastoma includes carboplatin (or cisplatin), cyclophosphamide, doxorubicin, and etoposide, but others may be used. For children in the high-risk group, larger combinations are used, and the drugs are given at higher doses, which may be followed by a stem cell transplant (described further on).

Doctors give chemo in cycles, which consist of treatment on a few days in a row, followed by time off to allow the body time to recover. The cycles are typically repeated every 3 or 4 weeks. The total length of treatment depends on which risk group the child is in – higher risk groups usually require longer treatment.

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, the lining of the mouth and intestines, and the hair follicles, also divide quickly. These cells are also likely to be affected by chemotherapy, which can lead to side effects.

The side effects of chemotherapy depend on the type and dose of drugs given and the length of time they are taken. General side effects of chemotherapy drugs can include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Diarrhea
• Increased chance of infections (due to low white blood cell counts)
• Easy bruising or bleeding (due to low blood platelet counts)
• Fatigue (due to low red blood cell counts)

Most of these side effects are short-term and tend to go away after treatment is finished. There are often ways to lessen these side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting. Be sure to ask your child’s doctor or nurse about medicines to help reduce side effects, and let him or her know if your child has side effects so they can be managed.

Along with the effects listed above, some drugs can have specific side effects. For example:

Cyclophosphamide and ifosfamide can damage the bladder, which can cause blood in the urine. The chance 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. These drugs can also damage the ovaries or testicles and may affect fertility (the ability to have children).

Doxorubicin can cause heart damage. Doctors try to reduce 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 (an ultrasound of the heart) during treatment. This drug can also cause skin damage if it should leak out of the vein while it is being given.

Cisplatin and carboplatin can affect the kidneys. Giving plenty of fluids can help reduce this risk. These drugs can also affect hearing. Your child’s doctor may order hearing tests (audiograms) during or after treatment.

Vincristine can damage nerves. Some patients may notice weakness, tingling, numbness, or pain, particularly in the hands and feet.

Chemotherapy may also have longer-term side effects in some cases. For example, some drugs used to treat neuroblastoma can increase the risk of later developing a cancer of white blood cells known as acute myeloid leukemia (AML). While this is a serious risk, it is not common, and the small increase in risk has to be weighed against the importance of chemotherapy in treating neuroblastoma. For more on the possible long-term effects of treatment, see the section, “Long-term effects of neuroblastoma and its treatment.”