Chemotherapy (also called 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. But it can also harm healthy cells that divide quickly, such as those that line your mouth and intestines or cause your hair to grow. Damage to healthy cells may cause side effects. Often, side effects get better or go away after chemotherapy is over.
Depending on your type of cancer and how advanced it is, chemotherapy can:
- Cure cancer - when chemotherapy destroys cancer cells to the point that your doctor can no longer detect them in your body and they will not grow back.
- Control cancer - when chemotherapy keeps cancer from spreading, slows its growth, or destroys cancer cells that have spread to other parts of your body.
- Ease cancer symptoms (also called palliative care) - when chemotherapy shrinks tumors that are causing pain or pressure.
Sometimes, chemotherapy is used as the only cancer treatment. But more often, you will get chemotherapy along with surgery, radiation therapy, or biological therapy. Chemotherapy can:
- Make a tumor smaller before surgery or radiation therapy. This is called neo-adjuvant chemotherapy.
- Destroy cancer cells that may remain after surgery or radiation therapy. This is called adjuvant chemotherapy.
- Help radiation therapy and biological therapy work better.
- Destroy cancer cells that have come back (recurrent cancer) or spread to other parts of your body (metastatic cancer).
This choice depends on:
- The type of cancer you have. Some types of chemotherapy drugs are used for many types of cancer. Other drugs 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
Treatment schedules for chemotherapy vary widely. How often and how long you get chemotherapy depends on:
- Your type of cancer and how advanced it is
- 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
You may receive chemotherapy in cycles. A cycle is a period of chemotherapy treatment followed by a period of rest. For instance, you might receive 1 week of chemotherapy followed by 3 weeks of rest. These 4 weeks make up one cycle. The rest period gives your body a chance to build new healthy cells.
Chemotherapy treats cancer with powerful drugs that travel through the bloodstream in order to:
- Destroy or slow the growth of cancer cells that have metastasized to other parts of the body
- Shrink the cancer tumors before surgery
- Relieve symptoms caused by cancer such as pain
Staging and Grading is the determination of the kinds of cells that make up the cancer and how fast it is growing. The stage and grade of a cancer helps doctors to predict how a cancer might behave, how it has progressed and how well it may react to treatment. Factors include:
- Location
- Site & spread
- Size & spread
- Types of cells
- Clinical history of the disease
- Health status
Depending on the type of cancer the patient has, chemotherapy drugs can be given by:
- Mouth - Tablets, capsules or liquids are given to patients so they are conveniently orally taken at home
- Injection - Injections can be given under the skin or into a muscle
- Intravenous (IV) - A small catheter is inserted into the vein of the hand or lower arm.
- IV infusion - IV infusions drip slowly; the period of time the drip continues may depend on the type and number of medications.
An implanted port may be recommended to those patients that require frequent and/or long-term delivery of medications directly into the bloodstream. A port can also be suggested by a doctor if smaller veins which are typically used for injection of medications are damaged, injured or have poor blood flow.
