Chemotherapy for Leukemia

Overview
Chemotherapy is the treatment of cancer with drugs that destroy or slow the growth of cancer cells. Some doctors may refer to all medication prescribed for someone with leukemia as chemotherapy. Chemotherapy is the most common treatment for people with certain types of leukemia. Some chemotherapy drugs must be infused intravenously (by IV), while others are injected or taken orally. Chemotherapy is usually prescribed by a medical oncologist – a doctor who specializes in treating cancer with medications.

For acute forms of leukemia – ALL and AML – chemotherapy is given in different phases of the disease for different purposes. Different drugs may be used in different phases. Induction therapy is initial treatment designed to destroy as many leukemia cells as possible and induce remission. During remission, people with leukemia may undergo consolidation (also called intensification) therapy to eradicate any remailing cancer cells and maintenance therapy to help prevent a relapse.

There are many classes of chemotherapy drugs for leukemia. Most chemotherapy drugs used for leukemia are given in combinations of two or more drugs depending on the type, stage, and genetic characteristics of your leukemia, the phase of treatment, whether you have tried other therapies before, and whether or not you are going to receive an allogeneic stem cell transplant. Some drugs are used for both children and adults with leukemia, while others are indicated only for use in children or adults. If your leukemia progresses despite treatment, or if you experience significant side effects, your medical oncologist may adjust your dosage or change the combination of drugs you receive.

Classes of chemotherapy drugs used for leukemia include alkylating agents, antimetabolites, plant alkaloids, anthracycline antibiotics, and enzymes. Alkylating agents such as Cytoxan (Cyclophosphamide) are believed to prevent the growth of cancer cells by inhibiting and damaging their DNA. Antimetabolites including Cytarabine, Fludara (Fludarabine), and Nipent (Pentostatin) interfere with a specific phase of cell division that prevents cancer cells from dividing. Plant alkaloids such as Oncovin (Vincristine) disrupt the structure of dividing cells. Anthracycline antibiotics including Adriamycin (Doxorubicin), Cerubidine (Daunorubicin), and Idamycin (Idarubicin) slow the growth of cancer cells by interfering with cell division. Erwinaze (Asparaginase Erwinia chrysanthemi) is an enzyme that deprives leukemia cells of an amino acid they require, thereby causing cell death.

Chemotherapy medications may be combined with other classes of drugs including corticosteroids such as Dexamethasone and Prednisone or immunomodulators like Methotrexate. These drugs may enhance the effects of chemotherapy or reduce side effects.

Targeted therapies such as biologics and tyrosine kinase inhibitors may be given during chemotherapy to improve the effectiveness of anticancer drugs. Biologics such as Campath (Alemtuzumab), Gazyva (Obinutuzumab), and Rituxan (Rituximab) are genetically engineered proteins that can kill cancer cells directly or aid the immune system in targeting and destroying cancer cells. Tyrosine kinase inhibitors such as Gleevec (Imatinib), Imbruvica (Ibrutinib), Sprycel (Dasatinib), and Tasigna (Nilotinib) help suppress the growth of cancer cells.

Most people with leukemia receive a chemotherapy regimen that involves two or more medications from different drug classes.

Chemotherapy begins immediately after diagnosis in cases of acute lymphoblastic leukemia (ALL) due to its fast-growing nature. Chemotherapy regimens commonly used to treat ALL include:

• Hyper-CVAD (Cytoxan, Vincristine, Adriamycin, and Dexamethasone)
• Vincristine, Erwinaze, and a corticosteroid

Drug combinations commonly used for chemotherapy to fight acute myeloid leukemia (AML) include:

• Cytarabine with Cerubidine or Idamycin is used for induction therapy.
• HiDAC (Cytarabine at higher doses, in combination with Cerubidine) is used as consolidation therapy.

Drug combinations commonly used for chemotherapy to fight chronic lymphocytic leukemia (CLL) include:

• FCR (Fludara, Cytoxan, and Rituxan)
• PCR (Pentostatin, Cytoxan, and Rituxan)
• FR (Fludara and Rituxan)
• Campath and Rituxan

In cases of chronic myeloid leukemia (CML), chemotherapy is typically only used during a blast phase (blast crisis) to return the condition to its chronic phase, or if tyrosine kinase inhibitors have stopped working. Chemotherapy drugs utilized for blast-phase CML include:

• Cytoxan
• Cytarabine
• Oncovin
• Busulfan
• Hydroxyurea

What does it involve?
A course of chemotherapy is administered in cycles of treatment and recovery. A cycle is usually three or four weeks long. During treatment, chemotherapy is administered for several days. Each period of treatment will be followed by a recovery period to allow your body to rest. Your medical oncologist will determine your chemotherapy schedule based on many factors, including the type and stage of your leukemia, how well your cancer responds to treatment, and the severity of the side effects you experience.

If leukemia fails to respond after the first few cycles of chemotherapy with one drug combination, your medical oncologist may recommend switching to a different combination. If an initial round of chemotherapy successfully delays progression for a time, but your leukemia later relapses, your doctor may suggest undergoing another course of chemotherapy with the same or a different drug combination.

Before you begin chemotherapy, it is a good idea to work on improving your overall health. Get plenty of rest and avoid stress. Eat a healthy diet focused on whole grains, fresh vegetables, and fruit. Get regular exercise. Visit your dentist for a check-up and cleaning. Ask your doctor whether you need flu or pneumonia vaccinations or other immunizations. These steps can help you cope with side effects and avoid infections during chemotherapy treatment.

Before chemotherapy treatment begins, your medical oncologist will review the results of all of your tests and scans and recommend chemotherapy regimens that may work for you. They will go over the benefits and side effects associated with each option. Once a regimen has been chosen, the oncologist will walk you through the treatment consent form and get your signature.

If you are taking chemotherapy drugs orally, you can do it at home. If you are taking chemotherapy drugs intravenously, you will usually need to receive them in a clinical setting such as a doctor’s office or cancer treatment center. You may receive them through a slow-drip IV infusion in your hand or arm, as an intramuscular (into the muscle) or subcutaneous (under the skin) injection, or you may have a line or a port implanted.

A line or port is a flexible plastic tube inserted just under the skin in your arm or chest. If you receive a port or a line for chemotherapy, it will be placed during a brief outpatient surgery. The benefit of having a device implanted for chemotherapy is that you can receive medication or have blood taken through them without having the discomfort of a needle stick each time. If you do have a line or a port, monitor the skin around the device carefully for any sign of infection. After your chemotherapy treatments are finished, the device will be quickly and easily removed.

Each chemotherapy treatment can last one or several hours. To help pass the time, you can bring books, an electronic tablet or a laptop, knitting, materials for writing letters, puzzles, a board game and a friend, or anything else that you might enjoy. You can also take a nap.

After a chemotherapy session, the nurse or chemotherapy technician may check your vitals again to make sure you are stable after receiving the drugs. You may feel able to drive yourself home, but it might be easier to arrange a ride in advance. You may feel very fatigued and need to rest for a day or two after receiving chemotherapy. Be sure to drink plenty of fluids in order to avoid dehydration and constipation. Avoid beverages containing alcohol and caffeine, since they can worsen dehydration.

While you are undergoing chemotherapy treatment, your doctor will order tests regularly to check the effectiveness of the drug regimen and the severity of any side effects. Your doctor may change your chemotherapy regimen based on the results of these tests.

Intended Outcomes
In people with leukemia, chemotherapy can help slow or stop the growth of cancer cells. In some cases, chemotherapy can result in complete remission from leukemia.

Results
The effectiveness of chemotherapy in cases of leukemia varies widely by type and stage of leukemia, specific genetic characteristics of leukemia cells, which chemotherapy regimen is used, and whether it is combined with other drugs. The recent introduction of several new medications has improved overall results for leukemia treatment, but the novelty of the drugs means that there is limited comparative data on long-term results such as relapse rate and survival rate.

Constraints
Most chemotherapy drugs work against cells that divide and multiply very quickly. This makes them effective against cancer cells. However, healthy cells in certain parts of your body –
bone marrow, skin, hair, and the lining of the digestive system – also divide rapidly. Therefore, many common side effects of chemotherapy are related to damage in these areas.

Each class of chemotherapy drugs causes different side effects, some of which are very serious. What side effects you experience will depend on many factors including which drug combination your doctor prescribes, your dosage, and how well your body can tolerate the treatment. If you cannot tolerate the side effects, your doctor will try decreasing dosage or changing the combination in an effort to minimize danger and discomfort. Always report side effects to your doctor. Some side effects, such as nausea, can be eased with other medications.

Some of the most common side effects of chemotherapy include fatigue, nausea, vomiting, diarrhea, loss of appetite, weight loss, neuropathy (nerve pain, tingling, or numbness), hair loss, and mouth sores. Damage to bone marrow often results in a weakened immune system due to low white blood cell counts. You may bruise or bleed easily due to low levels of platelets, a blood component that causes clotting. Anemia (low red blood cell count) contributes to fatigue, dizziness, and shortness of breath. Other side effects of chemotherapy can include severe exhaustion, trouble swallowing, joint pain and skin changes such as nail discoloration and thin, brittle hair. Chemotherapy may also cause skin problems such as bruising or bleeding at the injection site, chest pain, fever and chills, or allergic reactions. Some people report cognitive side effects from chemotherapy such as memory problems and trouble focusing or planning. These cognitive issues are sometimes referred to as “chemo brain.” These side effects usually disappear soon after the end of treatment, although fatigue may last for years after treatment is over.

Chemotherapy treatment also affects male and female reproduction in many ways, both temporary and permanent. People who will be taking drugs that can cause infertility may choose to store sperm or fertilized eggs so that they can try for pregnancy at a later time. It is possible to become pregnant while receiving chemotherapy, but chemotherapy drugs taken by the father or mother can cause harm to a developing fetus. Talk to your doctor about safe and effective birth control methods to use while on chemotherapy. Chemotherapy medications can stay in the system for some months after treatment ends, so discuss safe timing with your doctor before trying to conceive.

Some chemotherapy drugs can cause neuropathy, or nerve damage. This may result in pain, tingling, or numbness in the extremities. These symptoms may be temporary or permanent.

Some potential late side effects of chemotherapy for leukemia can arise months or even years after treatment is complete. Some chemotherapy drugs can cause cardiotoxicity, or damage to the heart. This damage can lead to arrhythmia (changes in heart rhythm) or cardiomyopathy (deterioration of the heart muscle). Other drugs can damage the lungs, bring on early menopause, or make some people susceptible to other cancers in the years following treatment.

Out-of-pocket expenses for chemotherapy treatments can be difficult for some people to afford. Others find it impossible to work during or after leukemia treatment. For these reasons, some people may find it difficult to recover financially after treatment for leukemia.

For more details about this treatment, visit:

ALL: Chemotherapy – Leukemia & Lymphoma Society
http://www.lls.org/leukemia/acute-lymphoblastic...

AML: Chemotherapy and Drug Therapy – Leukemia & Lymphoma Society
https://www.lls.org/leukemia/acute-myeloid-leuk...

Chemotherapy for Chronic Myeloid Leukemia – American Cancer Society
https://www.cancer.org/cancer/chronic-myeloid-l...

CML: Chemotherapy – Leukemia & Lymphoma Society
https://www.lls.org/leukemia/chronic-myeloid-le...

Typical Treatment of Chronic Lymphocytic Leukemia – American Cancer Society
https://www.cancer.org/cancer/chronic-lymphocyt...

CLL: Chemotherapy and Drug Therapy – Leukemia & Lymphoma Society
https://www.lls.org/leukemia/chronic-lymphocyti...

Hyper-CVAD – National Cancer Institute
https://www.cancer.gov/about-cancer/treatment/d...

Drugs Approved for Leukemia – National Cancer Institute
https://www.cancer.gov/about-cancer/treatment/d...

Understanding Maintenance Therapy – Cancer.net
https://www.cancer.net/navigating-cancer-care/h...

Acute Myeloid Leukemia Consolidation – Texas Oncology
https://www.texasoncology.com/types-of-cancer/l...