Chemotherapy is the use of drugs to treat cancer.
Chemotherapy is typically used to treat malignant or higher grade tumors, but may also be used to treat low grade and benign tumors.
The goals of chemotherapy are to stop tumor growth by rendering the cells unable to duplicate themselves or to artificially start the normal process of cell death (apoptosis).
There are two main types of chemotherapy drugs:
Cytostatic: These drugs prevent cells from reproducing. They include:
- Anti-angiogenesis agents/Angiogenesis inhibitors—These drugs prevent the development of blood vessels around the tumor that provide it with the nutrients it needs to grow.
- Growth factor inhibitors—These agents limit the supply of growth factors, which prevent the tumor from becoming larger.
Cytotoxic: These drugs artificially start the process of cell death. They include:
- Alkylating agents—These drugs affect DNA in tumor cells in a way that prevents them from reproducing.
- Antimetabolites—These agents stop tumor cells from making the enzymes needed for new cell growth.
- Anti-tumor antibiotics—These drugs stop the action of enzymes needed for cell growth, and may be able to change the environment around the cell.
- Hormones—These substances may interfere with tumor growth by blocking the production of certain proteins in the tumor cells.
- Mitotic inhibitors—These agents are usually plant-based, natural substances that interfere with the production of the proteins needed to create new cells.
- Steroids—These drugs are used to decrease swelling around the tumor. While they are not intended to be “cytotoxic” therapy, some researchers believe that steroids have a toxic effect on tumor cells.
How Chemotherapy is Delivered
Chemotherapy drugs are delivered to tumor cells in one of two ways:
- Systemic Delivery: Systemic drugs travel through the body in the bloodstream, cross the blood brain barrier, and enter the tumor cells. These drugs are injected into an artery, vein, muscle, or the skin, or are taken by mouth.
- Local Delivery: Some drugs can be placed closer to the tumor, or within the areas of tumor growth. The goals of local delivery are to avoid delivering drugs throughout the body and to increase the concentration of the drug at the tumor site.
Potiental Side Effects
Chemotherapy drugs have the greatest effect on cells that reproduce rapidly, like those in a tumor. However, the drugs cannot always tell the difference between tumor cells and healthy cells. As a result, cells that reproduce the fastest are also the most prone to the side effects of chemotherapy. Some of the more common side effects of chemotherapy are:
- Fetal injury
Your doctor can provide more information about the specific side effects associated with a particular type of chemotherapy.
Like any treatment, chemotherapy carries risks. Some of these are the more common side effects, mentioned above. Other, rarer risks include:
- Interactions with other drugs
- Balance or coordination problems
- Memory or cognitive problems
- Brain swelling
- Damage to internal organs
- Coma (very rare)
- Death (very rare)
Your doctor or nurse can help you balance the risks of chemotherapy against the potential benefits.
It is important to note that the information provided here is basic and does not take the place of professional advice. If you have any questions about how brain tumors are treated, please contact your doctor.