Chemotherapy (chemo) uses anti-cancer drugs that are usually given into a vein (IV) or taken by mouth. These drugs enter the bloodstream and reach almost all areas of the body. However, many chemo drugs aren't able to enter the brain and reach tumor cells.
For some brain tumors, drugs can be given directly into the cerebrospinal fluid (CSF, the fluid that bathes the brain and spinal cord), either in the brain or into the spinal canal below the spinal cord. To help with this, a thin tube known as a ventricular access catheter may be inserted through a small hole in the skull and into a ventricle of the brain during a minor operation (see Surgery for Adult Brain and Spinal Cord Tumors).
When might chemotherapy be used?
In general, chemo is used for faster-growing brain tumors. Some types of brain tumors, such as medulloblastoma and lymphoma, tend to respond better to chemo than others. Chemo is not as helpful for treating some other types of tumors, such as spinal cord tumors, so it is used less often for these tumors.
Chemo is most often used along with other treatments such as surgery and/or radiation therapy. Chemo can also be used by itself, especially for more advanced tumors or for tumors that have come back after other types of treatment.
Chemo drugs used to treat brain and spinal cord tumors
Some of the chemo drugs used to treat brain and spinal cord tumors include:
- Carmustine (BCNU)
- Lomustine (CCNU)
These drugs can be used alone or in combinations, depending on the type of brain tumor. Chemo is given in cycles, with each period of treatment followed by a rest period to give the body time to recover. Each cycle typically lasts for a few weeks.
Carmustine (Gliadel) wafers: These dissolvable wafers contain the chemo drug carmustine (BCNU). After the surgeon removes as much of the brain tumor as is safe during a craniotomy, the wafers can be placed directly on or next to the parts of the tumor that can’t be removed. Unlike IV or oral chemo that reaches all areas of the body, this type of therapy concentrates the drug at the tumor site, producing few side effects in other parts of the body.
Possible side effects of chemotherapy
Chemo drugs can cause side effects. These depend on the type and dose of drugs, and how long treatment lasts. Common side effects can 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, changes in metabolism, or other factors)
Some of the most effective drugs against brain tumors tend to have fewer of these side effects than other common chemo drugs. Most side effects usually go away after treatment is finished. There are often ways to lessen these side effects. For example, drugs can often help prevent or reduce nausea and vomiting.
Some chemo drugs can also cause other, less common side effects. For example, cisplatin and carboplatin can also cause kidney damage and hearing loss. Your doctor will check your kidney function and hearing if you are getting these drugs. Some of these side effects might last after treatment is stopped.
Be sure to report any side effects to your medical team while getting chemo, so you can be treated promptly. Sometimes, the doses of the drugs may need to be reduced or treatment may need to be delayed or stopped to prevent the effects from getting worse.