Chemotherapy for acute lymphoblastic leukemia

Chemotherapy uses drugs to destroy cancer cells. These drugs target rapidly dividing cells throughout the whole body. This means that chemotherapy kills cancer cells but it can also damage healthy cells.

With most types of chemotherapy, the drugs travel through the blood to reach and destroy cancer cells all over the body, including cells that may have broken away from the primary tumour. This is described as systemic therapy.

Sometimes chemotherapy is used as a regional therapy for a specific area of the body. Intrathecal chemotherapy gives chemotherapy drugs directly into the cerebrospinal fluid( CSF), which is fluid around the brain and spinal cord. This type of chemotherapy is given through a lumbar puncture( also called a spinal tap) or an Ommaya reservoir.

Long-term chemotherapy is the main treatment for acute lymphoblastic leukemia (ALL). It is given in 3 phases, usually for 2 to 3 years. These phases are called induction, consolidation (which may also be called intensification) and maintenance. Your healthcare team will use what they know about the cancer and about your health to plan the drugs, doses and schedules for your treatment (or therapy) in each phase.

If ALL doesn't respond to treatment (called refractory ALL) or comes back after treatment (relapses), your healthcare team may consider trying different drugs or increasing the dose of the drugs you are taking.

Chemotherapy may be the only treatment you have or it may be used along with other cancer treatments. You may have chemotherapy to:

• destroy leukemia cells, bring about a remission and return blood cell production to normal
• prevent leukemia cells from spreading to or treat leukemia cells in the brain and spinal cord (called the central nervous system, or CNS)
• prepare for a stem cell transplant

Chemotherapy can be given in different ways, which are called routes of administration. The way chemotherapy is given depends on the type of drug, the goal of treatment and the type and location of the cancer. You may be given chemotherapy drugs for ALL in the following ways:

• intravenously( through an IV)
• orally (by mouth) as a tablet
• as intrathecal chemotherapy (into the CSF)
• as an intramuscular injection (into a muscle)
• as a subcutaneous injection (just under the skin)

Find out more about how chemotherapy is given.

The most common chemotherapy drugs used to treat ALL are:

• vincristine
• daunorubicin (Cerubidine), doxorubicin or a similar anthracycline drug
• cyclophosphamide (Procytox)
• pegaspargase (Oncaspar) or crisantaspase recombinant (Rylaze)
• methotrexate
• cytarabine
• mercaptopurine (Purinethol)
• nelarabine (Atriance)

Steroids such as prednisone or dexamethasone are commonly used in combination with chemotherapy.

The most common chemotherapy combination used for induction treatment of ALL is vincristine, daunorubicin or doxorubicin, and dexamethasone or prednisone. Different versions of this regimen may also include:

• cyclophosphamide
• pegaspargase or crisantaspase recombinant
• high-dose methotrexate or high-dose cytarabine

Hyper-CVAD and adapted pediatric combinations are both commonly used for consolidation treatment of ALL.

Hyper-CVAD is a hyperfractioned chemotherapy. This means that your total daily dose of chemotherapy is divided into smaller doses and given to you multiple times throughout the day. The hyper-CVAD combination includes:

• cyclophosphamide
• vincristine
• doxorubicin
• dexamethasone

Hyper-CVAD is alternated with high-dose cytarabine and high-dose methotrexate in cycles of 3 to 4 weeks.

Chemotherapy regimens that are used to treat ALL in children have also been adapted for consolidation treatment for adults. These pediatric combinations include:

• pegaspargase or crisantaspase recombinant
• doxorubicin
• vincristine
• steroids

The most common chemotherapy combination used for maintenance treatment for ALL is weekly methotrexate and daily mercaptopurine. Other drugs that may be added include monthly vincristine and prednisone.

Relapsed (or recurrent) ALL is leukemia that has come back after treatment and reaching remission. If ALL relapses after a long remission, it may respond to the drugs used in the original treatment. If ALL relapses after a short remission, doctors will use other drugs.

Refractory ALL is leukemia that did not respond to treatment. It may be treated with different drugs, or more intense doses of drugs that you have already received. But even with different doses, these same drugs are still less likely to work.

For relapsed and refractory ALL, your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.

With ALL, leukemia cells can spread to the brain and spinal cord (called the central nervous system, or CNS). Treatment given to prevent leukemia cells from spreading to the CNS is called CNS prophylaxis. During each phase of your treatment, you may receive CNS prophylaxis or treatment to kill leukemia cells that have already spread to the CNS.

To prevent ALL from spreading to the CNS or to treat ALL in the CNS, drugs are given directly into the cerebrospinal fluid (CSF) through a lumbar puncture or an Ommaya reservoir.

The most common chemotherapy drugs used for CNS prophylaxis or treatment of ALL that has spread to the CNS include:

• methotrexate
• cytarabine
• a steroid such as prednisone

Side effects of chemotherapy will depend mainly on the drug, the dose, how it's given and your overall health. Tell your healthcare team if you side effects that you think might be from chemotherapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Common side effects of chemotherapy drugs for ALL include:

• hair loss
• mouth sores
• nausea and vomiting
• loss of appetite
• diarrhea and constipation
• low blood cell counts
• tumour lysis syndrome
• increased risk of developing a second cancer
• fertility problems

You may receive drugs that protect against the effects of chemotherapy. They may offered to help prevent fungal and viral infections or to treat people who have severe side effects from chemotherapy. Some of these drugs may include:

• leucovorin
• mesna

These drugs may be given intravenously or orally as a tablet.

Drugs called growth factors are sometimes offered after chemotherapy. Chemotherapy can cause low counts of white blood cells, red blood cells and platelets. This can lead to bruising and bleeding more easily than normal, fatigue, shortness of breath and a higher risk for infections. Growth factors can help raise your white blood cell count after you receive chemotherapy and prevent you from getting an infection. These drugs include:

• filgrastim (Neupogen)
• pegfilgrastim (Neulasta)

These drugs may be given as a subcutaneous injection or intravenously.

Find out more about chemotherapy and side effects of chemotherapy. To make the decisions that are right for you, ask your healthcare team questions about chemotherapy.

Details on specific drugs change quite regularly. Find out more about sources of drug information and where to get details on specific drugs.