Chemotherapy is a drug treatment that uses powerful chemicals to kill fast-growing cells in your body. Chemotherapy is most often used to treat cancer, since cancer cells grow and multiply much more quickly than most cells in the body. Many different chemotherapy drugs are available. Chemotherapy drugs can be used alone or in combination to treat a wide variety of cancers.
Though chemotherapy is an effective way to treat many types of cancer, chemotherapy treatment also carries a risk of side effects. Some chemotherapy side effects are mild and treatable, while others can cause serious complications.
Why it’s done
Chemotherapy is used to kill cancer cells in people with cancer. There are a variety of settings in which chemotherapy may be used in people with cancer:
- To cure the cancer without other treatments. Chemotherapy can be used as the primary or sole treatment for cancer.
- After other treatments, to kill hidden cancer cells. Chemotherapy can be used after other treatments, such as surgery, to kill any cancer cells that might remain in the body. Doctors call this adjuvant therapy.
- To prepare you for other treatments. Chemotherapy can be used to shrink a tumor so that other treatments, such as radiation and surgery, are possible. Doctors call this neoadjuvant therapy.
- To ease signs and symptoms. Chemotherapy may help relieve signs and symptoms of cancer by killing some of the cancer cells. Doctors call this palliative chemotherapy.
How does chemotherapy treat cancer?
Chemotherapy is a systemic medication. This means it travels through the bloodstream and reaches all parts of the body. There are many different kinds of chemotherapy. In general, drugs used for chemotherapy are powerful chemicals that treat cancer by attacking cells during specific parts of the cell cycle. All cells go through the cell cycle, which is how new cells are made. Cancer cells go through this process faster than normal cells, so chemotherapy has more of an effect on these fast-growing cells. Because chemotherapy travels through the whole body, it can also damage healthy cells as they go through their normal cell cycle. This is why chemotherapy can cause side effects.
What are the goals of chemotherapy?
The goals of chemotherapy depend on your type of cancer and how far it has spread. Chemotherapy can be given alone or as a part of a treatment plan that includes different treatments. Some of the ways chemotherapy is used include:
As the primary treatment. Sometimes, the goal of chemotherapy treatment is to get rid of all the cancer and keep it from coming back. This might be called “curative chemotherapy.”
Before other treatments. Chemotherapy can be given before surgery or radiation therapy to shrink tumors. This can be called “neoadjuvant chemotherapy.”
After other treatments. Chemotherapy can be given after surgery or radiation therapy to destroy any remaining cancer cells. This is called “adjuvant chemotherapy.”
To slow the progression of cancer and relieve symptoms. Even when the cancer is not curable, chemotherapy can partially shrink tumors and prevent tumor growth and spread for various lengths of time. In such settings, chemotherapy can extend survival, relieve cancer-related symptoms, and improve quality of life. Chemotherapy used for these purposes is sometimes called “palliative chemotherapy.”
Chemotherapy can be used to treat many types of cancers. It can also be used to treat recurrent cancer and metastatic cancer. Recurrent cancer is cancer that comes back after treatment. Metastatic cancer is cancer that has spread to other parts of the body.
Chemotherapy for conditions other than cancer
Some chemotherapy drugs have proved useful in treating other conditions, such as:
- Bone marrow diseases. Diseases that affect the bone marrow and blood cells may be treated with a bone marrow transplant, also known as a stem cell transplant. Chemotherapy is often used to prepare for a bone marrow transplant.
- Immune system disorders. Lower doses of chemotherapy drugs can help control an overactive immune system in certain diseases, such as lupus and rheumatoid arthritis.
Side effects of chemotherapy drugs can be significant. Each drug has different side effects, and not every drug causes every side effect. Ask your doctor about the side effects of the particular drugs you’ll receive.
Side effects that occur during chemotherapy treatment
Common side effects of chemotherapy drugs include:
- Hair loss
- Loss of appetite
- Mouth sores
- Easy bruising
Many of these side effects can be prevented or treated. Most side effects subside after treatment ends.
Long-lasting and late-developing side effects
Chemotherapy drugs can also cause side effects that don’t become evident until months or years after treatment. Late side effects vary depending on the chemotherapy drug but can include:
- Damage to lung tissue
- Heart problems
- Kidney problems
- Nerve damage (peripheral neuropathy)
- Risk of a second cancer
Ask your doctor if you have a risk of any late side effects. Ask what signs and symptoms you should be aware of that may signal a problem.
How you prepare
How you prepare for chemotherapy depends on which drugs you’ll receive and how they’ll be administered. Your doctor will give you specific instructions to prepare for your chemotherapy treatments. You may need to:
- Have a device surgically inserted before intravenous chemotherapy. If you’ll be receiving your chemotherapy intravenously — into a vein — your doctor may recommend a device, such as a catheter, port or pump. The catheter or other device is surgically implanted into a large vein, usually in your chest. Chemotherapy drugs can be given through the device.
- Undergo tests and procedures to make sure your body is ready to receive chemotherapy. Blood tests to check kidney and liver functions and heart tests to check for heart health can determine whether your body is ready to begin chemotherapy. If there’s a problem, your doctor may delay your treatment or select a different chemotherapy drug and dosage that’s safer for you.
- See your dentist. Your doctor may recommend that a dentist check your teeth for signs of infection. Treating existing infections may reduce the risk of complications during chemotherapy treatment, since some chemotherapy may reduce your body’s ability to fight infections.
- Plan ahead for side effects. Ask your doctor what side effects to expect during and after chemotherapy and make appropriate arrangements. For instance, if your chemotherapy treatment will cause infertility, you may wish to consider your options for preserving your sperm or eggs for future use. If your chemotherapy will cause hair loss, consider planning for a head covering.
- Make arrangements for help at home and at work. Most chemotherapy treatments are given in an outpatient clinic, which means most people are able to continue working and doing their usual activities during chemotherapy. Your doctor can tell you in general how much the chemotherapy will affect your usual activities, but it’s difficult to predict exactly how you’ll feel.Ask your doctor if you’ll need time off work or help around your home after treatment. Ask your doctor for the details of your chemotherapy treatments so that you can make arrangements for work, children, pets or other commitments.
- Prepare for your first treatment. Ask your doctor or chemotherapy nurses how to prepare for chemotherapy. It may be helpful to arrive for your first chemotherapy treatment well rested. You might wish to eat a light meal beforehand in case your chemotherapy medications cause nausea.Have a friend or family member drive you to your first treatment. Most people can drive themselves to and from chemotherapy sessions. But the first time you may find that the medications make you sleepy or cause other side effects that make driving difficult.
Determining which chemotherapy drugs you’ll receive
Your doctor chooses which chemotherapy drugs you’ll receive based on several factors, including:
- Type of cancer
- Stage of cancer
- Overall health
- Previous cancer treatments
- Your goals and preferences
Discuss your treatment options with your doctor. Together you can decide what’s right for you.
What types of chemotherapy are there?
Chemotherapy for cancer includes more than a 100 different drugs. Although all chemotherapy drugs damage cells, they attack different cell targets at different times during the cell cycle. Combining drugs that damage the cancer cell in different ways can increase how well the treatment works.
Below are the main types of chemotherapy:
- Alkylating agents
- Anti-tumor antibiotics
- Topoisomerase inhibitors
- Mitotic inhibitors
- Plant alkaloids
How chemotherapy drugs are given
Chemotherapy drugs can be given in different ways, including:
- Chemotherapy infusions. Chemotherapy is most often given as an infusion into a vein (intravenously). The drugs can be given by inserting a tube with a needle into a vein in your arm or into a device in a vein in your chest.
- Chemotherapy pills. Some chemotherapy drugs can be taken in pill or capsule form.
- Chemotherapy shots. Chemotherapy drugs can be injected with a needle, just as you would receive a shot.
- Chemotherapy creams. Creams or gels containing chemotherapy drugs can be applied to the skin to treat certain types of skin cancer.
- Chemotherapy drugs used to treat one area of the body. Chemotherapy drugs can be given directly to one area of the body. For instance, chemotherapy drugs can be given directly in the abdomen (intraperitoneal chemotherapy), chest cavity (intrapleural chemotherapy) or central nervous system (intrathecal chemotherapy). Chemotherapy can also be given through the urethra into the bladder (intravesical chemotherapy).
- Chemotherapy given directly to the cancer. Chemotherapy can be given directly to the cancer or, after surgery, where the cancer once was. As an example, thin disk-shaped wafers containing chemotherapy drugs can be placed near a tumor during surgery. The wafers break down over time, releasing chemotherapy drugs. Chemotherapy drugs may also be injected into a vein or artery that directly feeds a tumor.
How often you receive chemotherapy treatments
Your doctor determines how often you’ll receive chemotherapy treatments based on what drugs you’ll receive, the characteristics of your cancer and how well your body recovers after each treatment. Chemotherapy treatment schedules vary. Chemotherapy treatment can be continuous, or it may alternate between periods of treatment and periods of rest to let you recover.
Where you receive chemotherapy treatments
Where you’ll receive your chemotherapy treatments depends on your situation. Chemotherapy treatments can be given:
- In an outpatient chemotherapy unit
- In a doctor’s office
- In the hospital
- At home, such as when taking chemotherapy pills
You’ll meet with your cancer doctor (oncologist) regularly during chemotherapy treatment. Your oncologist will ask about any side effects you’re experiencing, since many can be controlled. Depending on your situation, you may also undergo scans and other tests to monitor your cancer during chemotherapy treatment. These tests can give your doctor an idea of how your cancer is responding to treatment, and your treatment may be adjusted accordingly.