What Is Chemotherapy?
Chemotherapy is a broad term for the use of drugs to kill cancer cells. Learn how it works and what you might expect from treatment.
Chemotherapy is a term for the various drug therapies used to treat cancer. In use since the 1950s, chemotherapy, or chemo, now encompasses more than 100 different cancer-fighting drugs.
How Chemotherapy Works
Your body is made of trillions of cells, which die off and multiply as part of a normal growth cycle. Cancer develops when abnormal cells in the body multiply at a rapid, uncontrolled rate. Sometimes these cells grow into tumors, or masses of tissue. Different types of cancer affect different organs and different parts of the body. Left untreated, cancer can spread.
Chemo drugs are specifically designed to stop cancer cells from dividing or slow their growth and may also be used to shrink a tumor prior to surgery. The drugs may also affect healthy cells, but they can usually repair themselves.
How Chemotherapy Is Administered
Chemotherapy can be administered in a variety of ways, depending on the type of cancer you have and where the cancer is located. These drugs include:
- Injections into the muscle or under the skin
- Infusions into an artery or vein
- Pills that you take by mouth
- Injections into the fluid around your spinal cord or brain
You may require a minor surgical procedure to have a thin catheter, called a central line or port, implanted into a vein to make it easier to administer the drugs.
Goals of Chemotherapy
Chemotherapy plans — along with other cancer-fighting therapies, such as radiation or immunotherapy — can have different goals, depending on your type of cancer.
- Curative This treatment plan is designed to wipe out all the cancer cells in your body and permanently put the cancer in remission.
- Control When curative treatment isn’t possible, chemotherapy may help manage the cancer by stopping it from spreading or by shrinking a tumor. The goal is to improve your quality of life.
Types of Chemotherapy
The type of treatment you'll receive will also vary depending on your cancer.
- Adjuvant chemotherapy This treatment is usually given after surgery to kill any cancer cells that may remain undetected, which helps prevent recurrences of the cancer.
- Neoadjuvant chemotherapy Because some tumors are too large to be removed surgically, this type of chemo aims to shrink the tumor to make surgery possible and less drastic.
- Palliative chemotherapy If the cancer has spread and is impossible to completely remove, a doctor might use palliative chemotherapy to relieve symptoms, make complications less likely, and slow the cancer’s progress or stop it temporarily.
Potential Side Effects
Chemotherapy drugs are divided into several different groups. Each works in different ways, and knowing how a drug works is important in predicting the side effects. Most people worry about the chemotherapy side effects, but the fear is often worse than the reality.
Chemo drugs are sometimes used in combination, depending on the type of cancer and its severity. Some interfere with the DNA inside cells or enzymes involved in DNA replication, and some stop cell division. The side effects depend on your chemotherapy treatment.
Side effects can occur because chemotherapy attacks healthy cells as well as cancer cells. Those healthy cells may include blood-producing cells, hair cells, and cells within the digestive system and mucous membranes. Short-term effects of chemo may include:
Your doctor can often effectively treat these side effects. For example, blood transfusions can improve anemia, antiemetic drugs can relieve nausea and vomiting, and pain medication can help relieve discomfort.
Cancer, an organization that provides support, counseling, education, and financial assistance for people with cancer and their families, offers a free guide to help you cope with side effects.
If your side effects are particularly bad, your doctor might perform blood tests to see if you need a lower dose or a longer break between treatments.
According to the American Cancer Society, it’s important to remember that the benefits of chemo can outweigh the risks of treatment. For most people, side effects usually end sometime after treatments end. How long that takes is different for each person.
How Will Chemo Affect My Life?
Chemotherapy’s interference in your normal routine depends on several factors, including how advanced your cancer is at the time of diagnosis and which treatments you undergo.
Many people can continue working and managing daily life during chemo, while others find that the fatigue and other side effects slow them down. But you may be able to get around some of the effects by having your chemo treatments late in the day or right before the weekend.
Federal and state laws may require your employer to allow flexible work hours during your treatment.