Cytogenetic characterization of childhood acute lymphoblastic leukemia in Nicaragua.
BACKGROUND
Within the frame of a twinning programme with Nicaragua, The La Mascota project, we evaluated in our study the contribution of cytogenetic characterization of acute lymphoblastic leukemia (ALL) as prognostic factor compared to clinical, morphological, and immunohistochemical parameters.


METHODS
All patients with ALL treated at the only cancer pediatric hospital in Nicaragua during 2006 were studied prospectively. Diagnostic immunophenotyping was performed locally and bone marrow or blood samples were sent to the cytogenetic laboratory of Zurich for fluorescence in situ hybridization (FISH) analysis and G-banding.


RESULTS
Sixty-six patients with ALL were evaluated. Their mean age at diagnosis was 7.3 years, 31.8% were >or=10 years. Thirty-four patients (51.5%) presented with hyperleucocytosis >or=50 x 10(9)/L, 45 (68.2%) had hepatosplenomegaly. Immunophenotypically 63/66 patients (95%) had a B-precursor, 2 (3%) a T- and 1 (1.5%) a B-mature ALL. FISH analysis demonstrated a TEL/AML1 fusion in 9/66 (14%), BCR/ABL fusion in 1 (1.5%), MLL rearrangement in 2 (3.1%), iAMP21 in 2 (3.1%), MYC rearrangement in 1 (1.5%), and high-hyperdiploidy in 16 (24%). All patients but two with TEL/AML1 fusion and high-hyperdiploidy were clinically and hematologically in the standard risk group whereas those with poor cytogenetic factors had clinical high-risk features and were treated intensively.


CONCLUSIONS
Compared to Europe, the ALL population in Nicaragua is older, has a higher proportion of poor prognostic clinical and hematological features and receives more intensive treatment, while patients with TEL/AML1 translocations and high-hyperdiploidy are clinically in the standard risk group. Cytogenetics did not contribute as an additional prognostic factor in this setting.
Ceppi
Francesco
F
Pediatric Hematology Oncology Unit, University Hospital, Lausanne, Switzerland. francesco.ceppi@chuv.ch
Brown
Angela
A
Betts
David R
DR
Niggli
Felix
F
Popovic
Maja Beck
MB
D000293:Adolescent; D000782:Aneuploidy; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D006529:Hepatomegaly / Q000453:epidemiology / Q000209:etiology; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics; D009527:Nicaragua / Q000453:epidemiology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics*; D011379:Prognosis; D011446:Prospective Studies; D012306:Risk; D013163:Splenomegaly / Q000453:epidemiology / Q000209:etiology; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D016044:Fusion Proteins, bcr-abl; D011495:Histone-Lysine N-Methyltransferase; D051788:Myeloid-Lymphoid Leukemia Protein; D015514:Oncogene Proteins, Fusion; C497422:KMT2A protein, human; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein