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Chemotherapy for brain and spinal cord cancer
Chemotherapy is commonly used to treat brain cancer. Chemotherapy is not usually used with tumours that start in the spine (primary spinal cord tumours), but may be used for tumours that have spread to the spine from other parts of the body (metastatic spinal cord tumours). The chemotherapy drugs used will depend on the type of primary 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. Chemotherapy may also be a regional therapy, given to specific areas of the body.
The blood-brain barrier is a protective network of blood vessels and cells that filters blood flowing to the brain. This barrier makes it hard for some substances (such as anti-cancer drugs) to enter the brain. It prevents many chemotherapy drugs from reaching brain tumour cells in large enough amounts to destroy them. The chemotherapy drugs used to treat brain tumours must be able to cross the blood-brain barrier.
Many types of brain tumours are naturally resistant to the effects of chemotherapy. However, some brain tumours, such as oligodendroglioma, may have genetic changes that make them more sensitive to chemotherapy drugs. Primary central nervous system lymphoma (PCNSL) is also sensitive to chemotherapy.
Chemotherapy may be used:
- after surgery or radiation therapy to destroy cancer cells left behind and to reduce the risk of the cancer recurring (adjuvantadjuvantTreatment given in addition to the first-line therapy (the first or standard treatment) to help reduce the risk of a disease (such as cancer) coming back (recurring). chemotherapy)
- with radiation therapy to improve the effect of radiation
Drugs, doses and schedules vary from person to person.
The most common chemotherapy drugs used to treat brain cancer are:
- temozolomide (Temodal)
- carmustine (BiCNU, BCNU)
- lomustine (CeeNU, CCNU)
- cisplatin (Platinol AQ)
- carboplatin (Paraplatin, Paraplatin AQ)
- etoposide (Vepesid)
- irinotecan (Camptosar)
- Methotrexate may be injected directly into the fluid-filled space around the brain and spinal cord (intrathecal injection).
- procarbazine hydrochloride (Matulane)
- vincristine (Oncovin)
These drugs may be used alone or in combination, depending on the type of brain tumour. The most common chemotherapy combinations used to treat brain cancer are:
- PCV – procarbazine hydrochloride, lomustine and vincristine
- vincristine (Oncovin) and cisplatin (Platinol) with either lomustine (CCNU) or cyclophosphamide (Cytoxan, Procytox)
If brain cancer does not respond to drugs used in earlier treatments or if it recurs, other drugs that may be used are:
- tamoxifen (Nolvadex, Tamofen)
- carboplatin (Paraplatin)
- etoposide (Vepesid)
For more detailed information on specific drugs, go to sources of drug information.
Chemotherapy for brain tumours may be given directly into the cerebrospinal fluid (CSF) in the ventricles of the brain. It is given through an Ommaya reservoir, which is a small, dome-shaped device with a short tube (catheter) attached to it that is placed during surgery. The chemotherapy drug is injected using a small needle inserted through the scalp into the Ommaya reservoir.
With some types of brain tumours, the surgeon may line the area from where the tumour was removed with special wafers (glial wafers or Gliadel). These wafers have concentrated doses of the drug carmustine (BiCNU, BCNU), which is released into the brain tissue as the wafers break down.
This method of chemotherapy delivers a concentrated amount of the chemotherapy drug to the area where the tumour was in the brain, while limiting the amount of normal cells in the body affected by the drug.
Glial wafers are not used often because other methods of delivering chemotherapy are simpler and more effective.
Convection-enhanced delivery (CED) is another way of giving chemotherapy that may be used to treat some cases of brain and spinal cord cancer. With CED, chemotherapy drugs are delivered by a small (tube) catheter placed into the tumour or the area where the tumour was removed (surgical bed). The catheter may come out through the skin or be attached to a reservoir under the skin. A pump is used to slowly infuse the chemotherapy drug into the tumour through the catheter.