ACUTE
MYELOGENOUS LEUKEMIA IN CHILDREN
Sverre
O. Lie1 on
behalf of the Nordic Society for Paediatric Haematology and Oncology
(NOPHO)
1Rikshospitalet, University Hospital, Oslo, Norway
Childhood acute myeloid
leukaemia (AML) is less common, more heterogeneous and carries a poorer
prognosis than acute lymphoblastic leukemia. In recent years however,
large-scale therapeutic trials have shown a gradual improvement in the
results of chemotherapy and post remission consolidation therapy. According
to the best results published, up to half of all children with this disease
are probably cured. However, the therapy needs to be intense and the trend
is still to increase the intensity of therapy.
In
the Nordic countries, three consecutive protocols have been used since 1984
for childhood AML: NOPHO-84 was of moderate intensity, NOPHO-88 of very
high intensity with upfront loading and aggressive consolidation. NOPHO-93
utilizes the same treatment blocks as NOPHO-88, but after the first block,
the child is allowed to recover from aplasia. The type of response
determines subsequent induction therapy.
From
January 1993 to July 1999, 204 children were recruited to NOPHO-93. Thirty
children had Down syndrome (DS). Their p-EFS value was 0.82. For non-Down syndrome (Non-DS,
n=174) the results have improved significantly compared with NOPHO-88. CR
rate increased from 86% to 91%. p-EFS at 7 years increased from 0.42±0.04 to 0.56± 0.04(p<0.05). Toxic death during
induction was reduced.
The
major prognostic factor was the in vivo response to the first block of
therapy. In 114 of 174 patients (66%), remission was achieved after one
block. p-EFS of this group was 0.61±0.05. The 56 patients who needed
additional blocks had a p-EFS of 0.33±0.10 (p<0.01).
Cytogenetic
results were obtained from 167/174 (96%) children with clonal aberrations
in 67%. Except for 11q23, which carried a better prognosis (EFS 0,76), no
impact of karyotypes on prognosis was found.