Chemotherapy (or chemo) is a type of cancer treatment that uses drugs to destroy cancer cells. Chemotherapy works by stopping or slowing the growth of cancer cells, which grow and divide quickly. Healthy cells can also be affected by chemotherapy treatments. Damage to healthy cells may cause side effects. The goal of chemotherapy is to eliminate the cancer cells, while minimizing the negative effect on normal, healthy cells.
Sometimes, chemotherapy is used as the only cancer treatment. However, it is more likely that you will get chemotherapy along with surgery, radiation therapy, or biologic therapy.
Chemotherapy is used for a variety of purposes. It can:
- Shrink a tumor before surgery or radiation therapy.
- Destroy microscopic cancer cells that may remain after surgery or radiation.
- Destroy cancer cells that have come back or spread to other parts of your body.
- Control tumor growth when a cure is not possible.
- Ease cancer symptoms, such as shrinking a tumor that is causing pain or pressure.
- Help radiation therapy and biologic therapy work better.
How often and how long you receive chemotherapy depends on:
- The type and stage of cancer
- The goals of treatment (whether chemotherapy is used to cure your cancer, control its growth, or ease the symptoms)
- The type of chemotherapy
- How your body reacts to chemotherapy
In general, chemotherapy is given in cycles. During a cycle, you may get treatment every day, every week, or every month. Each treatment cycle is followed by a period of rest where you won't get chemotherapy. This rest period gives your body a chance to build new healthy cells.
Types of chemotherapy
Chemotherapy is divided into categories based on how they work to kill cancer. Your doctor will choose your chemotherapy based on:
- The type of cancer you have. Some types of chemotherapy drugs are used for many types of cancer; others are used for just one or two types of cancer.
- Whether you have had chemotherapy before.
- Whether you have other health problems, such as diabetes or heart disease.
Chemotherapy can be given in many forms:
- Intravenous (IV) - Directly into a vein. (See Table.)
- Injection - Through a shot into the muscle or another part of your body.
- Oral - Taken by mouth, either in pill, liquid, or capsule form.
- Topical - A cream rubbed directly onto the skin.
- Intra-arterial (IA) - Directly into the artery that is feeding the cancer.
- Intraperitoneal (IP) - Directly into the peritoneal cavity (the area that contains organs such as your intestines, stomach, liver, ovaries).
- Intrathecal - Directly into the spinal fluid.
Side effects of chemotherapy
Chemotherapy is designed to kill fast-growing cancer cells. But it can also affect healthy cells that grow quickly. These include cells that line your mouth and intestines, cells in your bone marrow that make blood cells, and cells that make your hair grow. Chemotherapy causes side effects when it harms these healthy cells.
Chemotherapy affects people in different ways, and although there are some common side effects to the drugs, not everyone will experience them.
Some common side effects from chemotherapy are fatigue, nausea, vomiting, decreased blood cell counts, hair loss, mouth sores, and pain. Most side effects are temporary and will gradually go away after treatment finishes. Sometimes, chemotherapy causes long-term side effects that do not go away. Ask your doctor or nurse about your chance of having long-term side effects.
Doctors have many ways to prevent or treat chemotherapy side effects and help you heal after each treatment session. Talk with your doctor or nurse about which ones to expect and what to do about them. Make sure to let your doctor or nurse know about any changes you notice - they may be signs of a side effect.
Table: Receiving Intravenous (IV) Chemotherapy
Here are the different IV (given through a vein) methods by which chemotherapy may be delivered:
- Infusion. An infusion is given through a thin needle that is placed in a vein on your hand or lower arm. Your nurse will put the needle in at the start of each treatment and remove it when treatment is over.
- Catheter. This is a soft, thin tube. A surgeon places one end of the catheter in a large vein, often in your chest area. The other end stays outside your body. Most catheters stay in place until all your chemotherapy treatments are done. Catheters can also be used for drugs other than chemotherapy and to draw blood.
- Port. This is a small, round disc made of plastic or metal that is placed under your skin. A catheter connects the port to a large vein, most often in your chest. Your nurse can insert a needle into your port to give you chemotherapy or draw blood. If you keep the port after treatment ends, you'll need to get it flushed by a nurse every six weeks.
- Pump. These are often attached to catheters or ports. They control how much and how fast chemotherapy is delivered. External pumps remain outside your body. Most people can carry these pumps with them. Internal pumps are placed under your skin during surgery.
Source: National Cancer Institute