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Our highly trained specialists are available 24/7 via phone and on weekdays can assist through online chat. We connect patients, caregivers, and family members with essential services and resources at every step of their cancer journey. Ask us how you can get involved and support the fight against cancer. Some of the topics we can assist with include:
For medical questions, we encourage you to review our information with your doctor.
Chronic Lymphocytic Leukemia (CLL)
Chemotherapy (chemo) uses anti-cancer drugs that are taken by mouth or injected into a vein or muscle to kill or control cancer cells. These drugs enter the bloodstream and reach all parts of the body, so chemo can be useful for cancers that tend to spread throughout the body, like chronic lymphocytic leukemia (CLL).
Chemo isn’t used as often to treat CLL as it was in the past, now that more effective treatments have become available. But it is still used in some situations.
In the past, when people with CLL needed to be treated, chemo was usually part of the main treatment. But as newer, more effective immunotherapy and targeted drugs have become available, chemo is now used less often.
Chemo might be used (often along with an immunotherapy drug) if:
Chemo is also often an important part of the treatment for people getting a stem cell transplant.
Doctors give chemo in cycles, with each treatment period followed by a rest period to allow the body time to recover. Chemo cycles generally last about 3 to 4 weeks.
Because of the side effects it can cause (see below), chemo might not be recommended for people in poor health.
The chemo drugs most often used to treat CLL include:
Chemo drugs are often combined with an immunotherapy drug (known as chemoimmunotherapy, or CIT). Examples of common regimens include:
Chemo drugs attack cells that divide quickly, which is why they work against cancer cells. But other cells in the body, such as those in the bone marrow, the lining of the mouth and intestines, and the hair follicles, also divide quickly. This can lead to side effects.
Chemo side effects depend on the type and dose of drugs given and the length of time they are taken.
Common side effects include:
Chemo can also cause low blood cell counts, which can lead to:
Tumor lysis syndrome is another possible side effect of certain types of chemo:
This syndrome is most common in people who had large numbers of leukemia cells in their body before treatment. (This may be called bulky disease.) It most often happens with the first cycle of chemo.
When the CLL cells are killed, they break open and release their contents into the bloodstream. This can overwhelm the kidneys, which can't get rid of these substances all at once. This can lead to a build-up of excess amounts of certain minerals in the blood.
The excess minerals can cause kidney failure, heart problems, and nervous system problems. These might be prevented by giving a person extra fluids and certain drugs, such as sodium bicarbonate, allopurinol, febuxostat, and rasburicase.
The side effects from chemo usually go away once treatment is finished. There are often ways to lessen or even prevent some of them from happening. For instance, drugs can help prevent or reduce nausea and vomiting.
Be sure to ask your cancer care team about medicines to help reduce side effects, and let them know when you do have side effects so they can be managed before they get worse.
Drugs known as growth factors might be given to increase white blood cell counts and help reduce the chance of infection. These drugs include G-CSF (filgrastim), pegfilgrastim, and GM-CSF (sargramostim).
To learn more, see Supportive or Palliative Care for Chronic Lymphocytic Leukemia (CLL).
For more general information about how chemotherapy is used to treat cancer, see Chemotherapy.
To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
National Cancer Institute. Chronic Lymphocytic Leukemia Treatment (PDQ®)–Health Professional Version. 2025. Accessed at https://www.cancer.gov/types/leukemia/hp/cll-treatment-pdq on February 20, 2025.
National Comprehensive Cancer Network, Clinical Practice Guidelines in Oncology (NCCN Guidelines®): Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma, Version 2.2025. Accessed at https://www.nccn.org on February 20, 2025.
Rai KR, Stilgenbauer S. Selection of initial therapy for symptomatic or advanced chronic lymphocytic leukemia/small lymphocytic lymphoma. UpToDate. 2024. Accessed at https://www.uptodate.com/contents/selection-of-initial-therapy-for-symptomatic-or-advanced-chronic-lymphocytic-leukemia-small-lymphocytic-lymphoma on February 20, 2025.
Rai KR, Stilgenbauer S. Treatment of relapsed or refractory chronic lymphocytic leukemia. UpToDate. 2024. Accessed at https://www.uptodate.com/contents/treatment-of-relapsed-or-refractory-chronic-lymphocytic-leukemia on February 20, 2025.
Last Revised: March 20, 2025
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