Chemotherapy is the use of drugs for treating cancer. Chemotherapy is systemic therapy. This means that the drug enters the bloodstream and circulates to reach and destroy the cancer cells throughout the body.

Chemotherapy is useful for osteosarcoma that has spread through the bloodstream to the lungs and/or other organs or has a high risk of doing so. It is part of the treatment for most osteosarcomas, although some patients with low-grade osteosarcoma may not need it.

Most cases of osteosarcoma are treated with chemotherapy given before surgery (neoadjuvant chemotherapy) and after surgery (adjuvant chemotherapy). People with high-grade osteosarcoma whose tumors responded well to chemotherapy before surgery usually get the same chemotherapy after surgery for several months. People whose tumors responded poorly usually will get different chemotherapy after surgery.

The drugs used most often to treat osteosarcoma include:

• Methotrexate (given in high doses along with leucovorin to help prevent side effects)
• Doxorubicin (Adriamycin)
• Cisplatin or carboplatin
• Etoposide
• Ifosfamide
• Cyclophosphamide
• Actinomycin D (dactinomycin)
• Bleomycin

Usually, several drugs are given together.

Some common combinations of drugs include:

• High-dose methotrexate, doxorubicin, and cisplatin (sometimes with ifosfamide)
• Doxorubicin and cisplatin
• Dactinomycin, bleomycin and cyclophosphamide
• Ifosfamide and etoposide

Many experts recommend that the drugs be given in very high doses, which can affect the bone marrow, where new blood cells are made. In these cases, other drugs called growth factors (such as filgrastim, also known as Neupogen) may be given to help the body make new blood cells as quickly as possible.

Side effects of chemotherapy

Chemotherapy drugs work by attacking 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.

Children seem to have an advantage over adults when it comes to chemotherapy. They tend to have less severe side effects and recover from side effects more quickly. Because of this, doctors can give them higher doses of chemotherapy to try to kill the tumor.

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: Most chemotherapy drugs can cause side effects such as nausea and vomiting, loss of appetite, hair loss, and mouth sores.

Because chemotherapy can damage the blood-producing cells of the bone marrow, patients may have low blood cell counts. Low blood cell counts can result in:

• Increased chance of infection (from a shortage of white blood cells)
• Bleeding or bruising after minor cuts or injuries (from a shortage of platelets)
• Fatigue or shortness of breath (from low red blood cell counts)

Most of these side effects are short-term and tend to go away after treatment is finished. Often there are ways to lessen these side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting. Be sure to discuss any questions you have about side effects with the cancer care team, and tell them about any side effects you have so that they can be prevented or controlled.

Side effects of certain drugs: Some side effects are specific to particular drugs. Many of these serious side effects are rare, but they are possible. Discuss these with your cancer care team before treatment if you have concerns.

Ifosfamide and cyclophosphamide can cause bloody urine by damaging the lining of the bladder. This is called hemorrhagic cystitis. The chance of this happening can be lowered by giving a drug called mesna along with the chemotherapy and having the patient drink plenty of fluids.

Cisplatin may cause nerve damage (called neuropathy) leading to problems with numbness, tingling, and even pain in the hands and feet. Kidney damage (called nephropathy) can also occur after treatment with cisplatin. Giving lots of fluid before and after the drug is infused can help prevent this side effect. Cisplatin can sometimes cause problems with hearing (known as ototoxicity). Most often patients with this problem notice problems hearing high- pitched sounds.

High-dose methotrexate may cause damage to the white matter of the brain (called leukoencephalopathy) and liver or kidney damage. Before starting high-dose methotrexate, medicines are given to help protect the kidneys. Methotrexate blood levels may be checked to see how much leucovorin (also called folinic acid) should be given to help stop any damage to normal tissues.

Doxorubicin (Adriamycin) can cause heart damage over time. The risk of this happening goes up as the total amount of the drug that is given goes up. Your (child's) doctor may order a test of heart function before and during treatment to see if this drug is affecting the heart. Another drug called dexrazoxane may be given along with the chemotherapy to help lessen the possible damage.

The doctors and nurses will watch closely for side effects. Do not hesitate to ask your cancer care team any questions about side effects.

Long-term side effects: Some side effects may not go away or may not happen until years after treatment is finished. Examples include:

• Infertility
• Heart damage
• Developing a second cancer

Some of these long-term effects are described in the section, "What happens after treatment for osteosarcoma?"

Tests to check for side effects of chemotherapy: Before giving these drugs, your (child's) doctor will check lab test results to be sure the liver, kidney, and bone marrow are functioning well.

The complete blood count (CBC) includes counts of white blood cells (WBCs), red blood cells (RBCs), and blood platelets. Chemotherapy can lower the numbers of these blood cells, so blood counts will be watched closely during and after chemotherapy. The cells usually reach their lowest point about 2 weeks after chemotherapy is given, though this can occur earlier with high-dose regimens.

Routine blood chemistry panels measure certain blood chemicals that tell doctors how well the liver and the kidneys are working. Some drugs used in chemotherapy can damage the kidneys and liver.

An audiogram may be done to check the patient's hearing, which may be affected by certain chemotherapy drugs.

If doxorubicin is to be given, tests such as an echocardiogram (an ultrasound of the heart) may be done to check heart function.

For more information on chemotherapy, see the document, Understanding Chemotherapy: A Guide for Patients and Families.

Last Medical Review: 01/14/2009
Last Revised: 01/14/2009