Chemotherapy for Leukemia

June 10, 2008 - 7:30am

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Chemotherapy for Leukemia

This page discusses the use of chemotherapy for the treatment of leukemia. For a thorough review of chemotherapy for cancer treatment, please see the ]]>chemotherapy treatment monograph]]> .

Chemotherapy is the use of drugs to kill malignant cells. Unlike radiation and surgery, which are localized treatments, chemotherapy is a systemic treatment, meaning that the drugs travel throughout the whole body. This means chemotherapy for leukemia may reach the bone marrow and all organs of the body, except perhaps the central nervous system. In this situation methods have been developed to administer chemotherapy directly to the fluid surrounding the nervous system to improve on cure rates.

Chemotherapy is commonly used to treat both acute and chronic leukemia. While chronic leukemias are incurable with chemotherapy agents alone, they are often less aggressive at the time of diagnosis.

Acute Leukemia

Acute leukemia requires immediate medical care. There are three traditional steps where chemotherapy treatment has a role for acute myeloid leukemia: induction, post remission, and post relapse.

Induction
Induction is the initial treatment and aims to bring about complete remission. About a week or two after completing this phase of the treatment, the doctor will perform a bone marrow biopsy and aspiration to check for leukemia cells. Bone marrow checks may be done subsequently to monitor progress, especially when blood counts have recovered from the induction chemotherapy. To reach remission, several courses of chemotherapy may be necessary. The length of treatment varies depending on the response. One typical combination regimen lasts seven days.

Post Remission
Even when induction therapy seems to produce a complete remission, some leukemia cells may be present. Additional chemotherapy is given to obtain long-term disease-free survival. Post-remission therapy includes two phases:

Consolidation – chemotherapy at a dose equal to that needed to achieve remission. The length of treatment varies depending on the response, but typically includes two to four more courses of therapy. In some situations, ]]>bone marrow transplantation]]> may be included at this point, either as part of a clinical trial or out of consideration for what might be the most appropriate treatment of all options available.
Maintenance – chemotherapy given at a lower-dose on an intermittent basis. It is not used as often as consolidation. Maintenance therapy may last two to three years in some cases.

Post Relapse
If the cancer recurs, additional chemotherapy, using different drugs, may be considered. Bone marrow transplantation may be another option in this situation.

Chronic Leukemia

Drug therapy for chronic myeloid leukemia is rapidly evolving due to the introduction of new agents and the completion of important new studies. ]]>Interferon]]> (a form of biologic therapy) and Ara-C (a chemotherapeutic drug) have been proven to induce remissions in CML. A newer agent, ]]>imatinib mesylate (Gleevec, STI-571)]]> , a drug that targets the specific molecular problem that occurs in CML, is changing thinking about the sequencing of drugs (both chemotherapeutic and otherwise) in the treatment of CML. Even when clinical and genetic remission occurs, relapse is still likely to occur within 36 months.

Chemotherapy for chronic lymphoid leukemia aims to control symptoms but is not thought to induce remission.

Chemotherapy Drugs Used for Leukemia

Most chemotherapy drugs are given intravenously (by IV) in cycles. Some therapy regimens may require hospitalization. The dose may vary depending on your age and overall health. Some of the more important agents used are listed below.

Acute Myeloid Leukemia (AML)

The following chemotherapy agents may be used to treat AML:

Cytarabine (Ara-C), given in both the induction and post-remission phases of treatment. It is given by IV or by injection.
Daunorubicin (Cerubidine), given for induction by IV.
Idarubicin (Idamycin), given by IV.

For relapse of AML, any of the following may be given. For combination protocols see below.

Amsacrine (AMSA), given by IV
Etoposide (Vespid), may be taken by mouth or given by IV
Idarubicin (Idamycin), given by IV
Mitoxantrone (Novantrone), given by IV
Topotecan (Hycamtin), given by IV

Acute Lymphoid Leukemia (ALL)

The following chemotherapy agents may be used to treat ALL:

Daunorubicin (Cerubidine), given by IV
Vincristine (Oncovin), given by IV
Prednisone, taken by mouth
l-Asparaginase (Elspar), given by IV
Methotrexate

For relapse of ALL:

Cyclophosphamide (Cytoxan), given by IV
Doxorubicin (adriamycin), given by IV
Methotrexate (Mexate), given by IV
Mitoxantrone (Novantrone), given by IV
Teniposide (vm-26), given by IV

Chronic Myeloid Leukemia (CML)

For the treatment of CML, ]]>imatinib mesylate (Gleevec, STI-571)]]> may be given. In addition, the following chemotherapy drugs may be used:

Cytarabine (Ara-C), given with ]]>interferon]]>
Hydroxyurea, taken by mouth
Busulfan (Myleran), taken by mouth and typically used for patients who cannot tolerate any other medications
Chlorambucil, daily infusions for several weeks or a higher dose given every three to four weeks
Cyclophosphamide (Cytoxan), given by IV
Fludarabine (Fludara), given by IV
Prednisone, taken by mouth
Ritual, a monoclonal antibody directed against CD20 on the cell surface.

Combination Therapies

Research continues to find the optimal combinations.

For Acute Myeloid Leukemia (AML)

One combination used is called “7 and 3.” It is a week-long treatment given in the hospital as induction therapy. It includes:

Ara-C, given during a continuous IV infusion for seven days.
Daunorubicin, given intravenously daily for three days

In some studies, Ara-C is given again at high dose for 3 days at the end of the 7 days.

For Acute Lymphoid Leukemia (ALL)

A common combination is DVP:

Daunorubicin given by IV in the hospital
Vincristine, given by intravenous injection
Prednisone, given orally for 4 weeks.

Effectiveness

Acute Myeloid Leukemia (AML)

Chemotherapy brings complete remission for about 65% of patients with acute myeloid leukemia. Your age, the cancer's resistance to the drugs given, and the success of ]]>supportive care to manage your side effects]]> will all have an impact on the success of your treatment. Improvements in remissions have been attributed to better supportive care.

About 20% to 30% of patients with AML caused by prior cancer treatments (secondary AML) achieve complete remission. With post-remission therapy, the remission may last 1 to 1.5 years. Post-relapse patients who responded well to prior chemotherapy typically fair better with additional chemotherapy.

Complications of treatment may include death. This is less likely in younger patients. Approximately 25% of AML patients over the age of 60 die from complications arising from their initial treatment regimen. Elderly patients who cannot tolerate induction treatment may be treated with low dose Ara-C by continuous infusion instead of standard induction regimens.

Acute Lymphoid Leukemia (ALL)

Chemotherapy generally produces a complete remission in 95% of children with ALL. About 80% to 90% of adults with ALL obtain complete remissions with induction therapy. This typically occurs within four weeks of starting treatment. Remissions typically last 18 to 24 months. Disease-free long-term survival rates ranges from 70% to 75% in children with ALL and 30% to 40% in adults. Younger adults are likely to respond better than older adults. Patients presenting with highest white blood cell counts have a poorer prognosis.

Chronic Myeloid Leukemia (CML)

Drug therapy for CML produces five-year survival rates of 32% to 44%. Therapy is not thought to induce cures, but long-term cytogenetic remissions are reported. For young patients who have a matched related donor, bone marrow transplant remains a treatment commonly advised, as it has cured the majority of patients who do not sustain a serious complication.

Special Considerations

Chemotherapy can cause life-threatening side effects. Discuss the risks and benefits with your doctor.

For more information on chemotherapy for cancer treatment, including side effects and how to manage them, see the ]]>chemotherapy treatment monograph]]> .

Sources:

National Cancer Institute, National Institutes of Health

The Leukemia & Lymphoma Society

American Cancer Society

Abeloff M. Clinical Oncology , 2nd ed. Orlando, FL: Churchill Livingstone, Inc.; 2000: 388-419.

Bast R, et al. Cancer Medicine e5 . Hamilton, Ontario: B.C. Decker Inc.; 2000.

Nissen D. Mosby's Drug Consult . St. Louis, MO: Mosby, Inc.; 2002.

Last reviewed February 2003 by ]]>John Erban, MD]]>

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.