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Chemotherapy for childhood brain and spinal cord cancer
Chemotherapy is commonly used to treat childhood brain and spinal cord cancer.
Chemotherapy is the use of anti-cancer (cytotoxic) drugs to treat cancer. It is usually a systemic therapysystemic therapyTreatment that travels through the bloodstream to reach cells all over the body. that circulates throughout the body and destroys cancer cells, including those that may have broken away from the primary tumour. Systemic therapy may be given orally (by mouth) or intravenously (into a vein).
For some types of tumours, chemotherapy may be given as a regional therapy in one of the following ways.
- The drugs may be injected directly into the cerebrospinal fluid (CSF) through a lumbar puncture. This is called intrathecal or intraventricular chemotherapy.
- An Ommaya reservoir may be used to deliver the drugs into the CSF or directly into a tumour cyst. An Ommaya reservoir is a small dome shaped device that is placed under the scalp. The reservoir is attached to a small catheter or tube that is placed into a ventricle in the brain or in a tumour cyst. The device allows access to the CSF and eliminates the need for uncomfortable procedures, such as lumbar punctures.
Chemotherapy may be used:
- after surgery or radiation therapy to destroy any cancer cells left behind and reduce the risk of the cancer recurring (adjuvant chemotherapy)
- before surgery or radiation to shrink the tumour and make it easier to remove or treat with radiation (neoadjuvant chemotherapy)
- during radiation therapy to improve the effect of radiation
- instead of radiation therapy in children under the age of 3 years to avoid the effects of radiation on the developing brain
- if the tumour progresses or recurs
- after surgery, if the tumour can't be completely removed (incomplete resection), to stall the growth of the remaining tumour and allow for a second-look surgery
Drugs, doses and schedules may vary from child to child.
Until recently, chemotherapy was considered to be of little benefit in childhood brain and spinal cord cancer. This is because the blood-brain barrier prevents harmful substances, including drugs from getting into the brain. However, researchers have discovered that the presence of brain tumours disrupts the blood-brain barrier. As a result, some chemotherapy drugs can in fact cross the barrier to reach the tumour. Researchers have also found that some types of chemotherapy drugs (water-soluble drugs) can easily pass through the disrupted parts of the barrier. Other types of drugs (liposoluble, or fat soluble drugs) can pass through a blood-brain barrier that is not disrupted. Researchers are now focusing on finding the drugs that will be most effective against brain tumours.
The most common chemotherapy drugs used to treat childhood brain and spinal cord cancer are:
- carmustine (BiCNU, BCNU)
- lomustine (CeeNU, CCNU)
- procarbazine hydrochloride (Matulane)
- carboplatin (Paraplatin, Paraplatin AQ)
- cisplatin (Platinol AQ)
- cyclophosphamide (Cytoxan, Procytox)
- ifosfamide (Ifex)
- paclitaxel (Taxol)
- vincristine (Oncovin)
- etoposide (Vepesid, VP-16)
- teniposide (Vumon, VM-26)
- topotecan (Hycamtin)
- irinotecan (Camptosar, CPT-11)
- tamoxifen (Nolvadex, Tamofen)
- temozolomide (Temodal)
- thiotepa (ThioTEPA)
- vinblastine (Velbe)
- bleomycin (Blenoxane)
Other drug treatments
Other drugs may be used before surgery to treat swelling of the brain, seizures, nausea and vomiting. These drugs include corticosteroids, anti-convulsants and anti-emetics.