This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science.
This page was updated on June 1, 2022.
Chemotherapy, often referred to as "chemo," is one of the most common treatment options for many cancers. These anti-cancer drugs work by targeting rapidly growing cancer cells either throughout the body or in a specific area of the body.
When chemotherapy drugs travel through the bloodstream to reach cancer cells, it's known as systemic chemotherapy. When the drugs are directed to a specific area of the body, it's called regional chemotherapy.
This article will cover:
Cancer develops when cells multiply, grow and divide without control. Designed to halt that process, Chemotherapy treatment damages and destroys cancer cells so they aren’t able to continue dividing.
Both radiation therapy and chemotherapy work by destroying cancer cells, but they do so in different ways. With chemotherapy, drugs are used to target and kill cancer cells or stop them from dividing, while radiation therapy delivers high-energy X-rays to destroy cancer cells.
Chemotherapy may be used for:
This video demonstrates the process that allows chemotherapy drugs to kill cancer cells or slow down their growth.
Chemotherapy uses anticancer drugs to destroy rapidly rapidly dividing cancer cells or slow their growth.
The patient’s care team will identify the type of chemotherapy that’s most likely to inhibit cancer cell growth based on the stage, type and location of the cancer. The most common chemotherapy types are:
How and where chemotherapy drugs may be given depends on a variety of clinical factors and personal preferences. Patients may receive chemotherapy at home, in a clinic or outpatient care center, at a hospital or doctor’s office.
Chemotherapy drugs may be administered:
Chemotherapy drugs are very powerful and may cause side effects in caregivers and family members who come in contact with them. Patients should talk to their doctor before deciding whether to administer their own chemotherapy drugs (in pill, liquid or cream form), or whether to have them given by a medical professional. Patients who may require frequent injections or infusions may opt to get a port or catheter through which drugs may be administered more efficiently and with less pain. How the chemotherapy drugs are administered depends on a variety of factors, including:
Depending on each patient's treatment needs, chemotherapy drugs may be given in combinations, in addition to, or before and/or after other treatments, such as surgery, targeted therapy or radiation therapy.
Like every patient and every cancer, every chemotherapy treatment plan is different and tailored to the patient’s specific disease, treatment goals and personal preferences. If chemotherapy is part of the patient's treatment plan, the medical oncologist and care team will share the options and coordinate dosages and schedules. In most cases, chemotherapy is administered in time frames called cycles. The length of each cycle and the dosages recommended within each cycle depends on many factors, including the patient's diagnosis and treatment goals.
If patients choose to administer their own chemotherapy drugs, the doctor can offer advise about the dosage schedule, amounts and safety protocols for handling drugs. If infusion is the best option, the care team can advise when and where to go and how long the treatments will take.
Since infusion sessions may take several hours, patients may want to prepare for a long visit to the clinic, infusion center, hospital, or wherever treatment is taking place.
Before deciding that chemotherapy is the right treatment, it’s important to be informed and learn as much as possible about the risks and benefits and what to expect. Don’t hesitate to ask the cancer care team any questions that may help with preparation.
The American Cancer Society offers a helpful and comprehensive list of questions to ask the doctor or nurse before starting chemotherapy treatment. Some of those questions include:
Expect to follow up with a medical oncologist or other members of the care team after every chemotherapy session. If and when a follow-up visit is necessary depends on the patient's specific needs and where they are in their treatment.
It’s important to take some precautions during and after chemotherapy to ensure that it takes effect and doesn’t cause further harm.
Don’t engage in activities that may put the immune system at risk. Chemotherapy may weaken the immune system. Stay out of crowded spaces and avoid people who are sick or may be sick. Wash hands frequently, and avoid eating raw or undercooked foods.
Don’t make contact with bodily fluids. Chemotherapy drugs may be passed on to others. These drugs may be found in body fluids, including mucus, sweat, tears, semen, urine, vomit or stool. Keep bathrooms clean and immediately wash towels or clothing that may have fluids on them. Caregivers should wash hands frequently and wear double gloves when necessary.
Don’t get sunburned. Some patients find that they’re more sensitive to sunlight during and after chemotherapy, so it’s important to wear sunscreen and protective clothing (like hats) in the sun.
Don’t eat large meals. The side effects of chemotherapy (like nausea, mouth sores and vomiting) may make it difficult for patients hard to eat a complete meal. Try to focus on eating smaller meals throughout the day.
Don’t consume excessive amounts of alcohol. Chemotherapy may make patients more sensitive to alcohol. Some chemotherapy drugs don’t interact well with these drinks, so consult a doctor before drinking alcoholic beverages during chemotherapy.
Throughout treatment, a medical oncologist will monitor the progress of the patient’s chemotherapy regimen and modify his or her treatment plan accordingly.
Because chemotherapy drugs kill rapidly growing cancer cells, they also can harm healthy cells in the process. This can cause several different side effects.
It’s important to remember that one person's reaction to chemotherapy may be different from someone else’s, even when taking the same chemotherapy regimen. The severity of these side effects depends on the patient's health, age and the type of chemotherapy drugs given.
Chemotherapy side effects may include:
Chemotherapy prep checklist
Planning ahead for chemotherapy treatments may help make the patient more comfortable, keep track of important information and limit the number of things the patient will have to do after treatment.
Cancer Treatment Centers of America® (CTCA) is now City of Hope®, joining forces to expand patient access to personalized, comprehensive cancer care.
At City of Hope, our medical oncologists work closely with integrative care providers who offer services intended to help patients manage side effects and improve quality of life. Supportive care services that may be helpful to chemotherapy patients under certain circumstances include:
During treatment with chemotherapy, frequent doctor visits will be scheduled to determine how the treatment is going, it’s effect on the patient's body and how well it's doing its job and destroying cancer. During those visits, the patient may need to have several tests and exams, such as blood tests or magnetic resonance imaging (MRI) scans, to see how well the treatment is working. The doctor is the best resource to ask about the results of chemotherapy. He or she will keep the patient updated on the treatment's progress.
While it's important to pay close attention to side effects and share them with a doctor, patients shouldn't assume that their severity is associated with the treatment's success. In fact, side effects are not at all related to how well the chemotherapy is working.