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Treatment of most children with acute myelogenous leukemia
(AML) is divided into 2 phases of chemotherapy:
- induction
- consolidation (intensification)
Treatment of the M3 subtype (acute promyelocytic leukemia, or
APL) is slightly different, and is described separately below. Because
of the intensity of treatment and the risk of serious complications,
children with AML should be treated in cancer centers or hospitals that
have experience with this disease.
Induction
Treatment for AML uses combinations of drugs that are
different from those used for ALL. The drugs most often used are
daunorubicin (daunomycin) and cytarabine (ara-C), which are each given
for several days in a row. The schedule of treatment may be repeated in
10 days or 2 weeks, depending on how intense doctors want the treatment
to be. A shorter interval between treatments causes more severe side
effects but may be more effective in killing leukemia cells.
If the doctors think that the leukemia may not respond to just
2 drugs alone, they may add etoposide and/or 6-thioguanine. Children
with very high numbers of white blood cells or whose leukemia has
certain chromosome abnormalities may fall into this class.
Treatment with these drugs is repeated until the bone marrow
shows no more leukemia. This usually occurs after 2 or 3 treatments.
Preventing
relapse in the central nervous system: In most cases,
intrathecal chemotherapy (given directly into the cerebrospinal fluid,
or CSF) is also given to help prevent leukemia from relapsing in the
brain or spinal cord. Radiation therapy to the brain is used less
often. The risk for recurrence in the brain or spinal cord is lower in
children with AML than in children with ALL.
Consolidation (intensification)
This begins after the induction phase, when the bone marrow
has no more visible leukemia cells.
About 1 out of 5 children has a brother or sister who would be
a good stem cell donor. For these children, an allogeneic stem cell
transplant is often recommended. Most studies have found this improves
the chance for long-term survival over chemotherapy alone, although it
is also more likely to cause serious complications. For children with
good prognostic factors, some doctors may recommend just giving
high-dose chemotherapy, and reserving the stem cell transplant in case
the AML relapses.
For most children without a suitable stem cell donor,
consolidation consists of giving the chemotherapy drug cytarabine
(ara-C) in high doses. Daunorubicin may also be added. It is usually
given for at least several months.
Intrathecal chemotherapy (into the cerebrospinal fluid) is
usually given every 1 to 2 months for as long as intensification
continues.
Maintenance chemotherapy is not needed for children with AML
(other than those with APL).
An important part of treatment for AML is supportive care
(proper nursing care, nutrition supplements, antibiotics, and blood
transfusions). Without antibiotic treatment of infections or
transfusion support, the current 75% to 85% remission rate at the end
of induction would not be possible.
Refractory or recurrent AML
Less than 15% to 20% of children have refractory AML
(leukemia that does not respond to initial treatment). The outlook for
the child who doesn't go into remission is often poor, and doctors may
recommend some type of stem cell transplant if it can be done.
Children who are not in complete remission after induction
chemotherapy or whose leukemia relapses may benefit from a drug called
gemtuzumab ozogamicin (Mylotarg) as part of their treatment. Mylotarg
is a chemotherapy drug attached to a manmade antibody. The antibody is
designed to bring the chemotherapy directly to the AML cells. Early
results from small studies suggest this treatment may help improve
survival rates for some children with AML.
Generally, the outlook for a child whose AML relapses (comes
back) after treatment is slightly better than if a remission were never
achieved, but this depends on how long the initial remission was. In
more than half of cases of relapse, a second remission can be achieved
with more chemotherapy. The chance of getting a second remission is
better if the first remission lasted for at least a year, but long-term
second remissions are rare without a stem cell transplant. Many
different combinations of standard chemotherapy drugs have been used in
these situations, but the results have been mixed.
Most children whose leukemia has relapsed are good candidates
for clinical trials testing new treatment regimens. The hope is that
some sort of a remission can be attained so that an allogeneic stem
cell transplant can be done. If remission is achieved, a stem cell
transplant should be considered. Some doctors may advise a stem cell
transplant even when there is no remission. This can sometimes be
successful.
Last Medical Review: 08/19/2007
Last Revised: 05/14/2009
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