Treatment of recurrent ALL
If the ALL recurs (comes back) at some point during or after treatment, the child will
most likely be treated again with chemotherapy. Much of the treatment strategy depends
on how soon the leukemia returns after the first treatment. If the relapse occurs after a
long time, the same drugs might still be effective, so the same or similar treatment may
be used to try to get the leukemia into a second remission.
If the time interval is shorter, more aggressive chemotherapy with other drugs may be
needed. The most commonly used chemo drugs are vincristine, L-asparaginase,
anthracyclines (doxorubicin, daunorubicin, or mitoxantrone), cyclophosphamide,
cytarabine (ara-C), and epipodophyllotoxins (etoposide or teniposide). The child will also
receive a steroid (prednisone or dexamethasone). Intrathecal chemotherapy will also be
given.
For children whose leukemia comes back within 6 months of starting treatment or for
children with T-cell ALL who relapse, a stem cell transplant may be considered,
especially if the child has a brother or sister who is a good tissue type match. Stem cell
transplants may also be used for other children who relapse after a second course of
chemotherapy.
Some children have an extramedullary relapse, meaning that leukemia cells are found in
one part of the body (such as the cerebrospinal fluid [CSF] or the testicles) but are not
detectable in the bone marrow. In addition to intensive chemotherapy as described above,
children with spread to the CSF may get more intense intrathecal chemotherapy,
sometimes with radiation to the brain and spinal cord (if that area had not been already
treated with radiation). Boys with relapse in a testicle may get radiation to the area, and in
some cases may have the affected testicle removed by surgery.
If ALL doesn’t go away completely or if it comes back after a stem cell transplant, it can
be very hard to treat. For some children, newer types of immunotherapy (treatments that
boost the body’s immune response against the leukemia) might be helpful. For more on
these treatments, see the section “What’s new in childhood leukemia research and
treatment?”
Philadelphia chromosome-type ALL
For children with certain types of ALL, such as those with the Philadelphia chromosome
or other high-risk genetic changes, standard chemotherapy for ALL (as outlined above)
might not be as effective. A stem cell transplant may be advised if induction treatment
puts the leukemia in remission and a suitable stem cell donor is available.
Newer, targeted drugs such as imatinib (Gleevec) and dasatinib (Sprycel) are designed to
kill leukemia cells that contain the Philadelphia chromosome. These drugs are taken as
pills. Adding these drugs to chemotherapy seems to help improve outcomes, according to
studies done so far..