Relapse of TEL-AML1--positive acute lymphoblastic leukemia in childhood: a matched-pair analysis.
OBJECTIVE
The aim of this study was to investigate whether, in relapsed childhood acute lymphoblastic leukemia (ALL), the frequent genetic feature of TEL-AML1 fusion resulting from the cryptic chromosomal translocation t(12;21)(p13;q22) is an independent risk factor.


METHODS
A matched-pair analysis was performed within a homogeneous group of children with first relapse of BCR-ABL-negative B-cell precursor (BPC) ALL treated according to relapse trials ALL-Rezidiv (REZ) of the Berlin-Frankfurt-Münster Study Group. A total of 249 patients were eligible for this study: 53 (21%) were positive for TEL-AML1, and 196 (79%) were negative. Positive patients were matched for established most-significant prognostic determinants at relapse, time point, and site of relapse, as well as age and peripheral blast cell count at relapse.


RESULTS
Fifty pairs matching the aforementioned criteria could be determined. The probabilities with SE of event-free survival and survival at 5 years for matched TEL-AML1 positives and negatives are 0.63 +/- 0.10 versus 0.38 +/- 0.10 (P =.09) and 0.82 +/- 0.09 versus 0.42 +/- 0.19 (P =.10), respectively. These results were confirmed by multivariate analysis, revealing an independent prognostic significance of time point and site of relapse (both P <.001) but not of TEL-AML1 expression (P =.09).


CONCLUSIONS
TEL-AML1 expression does not constitute an independent risk factor in relapsed childhood BCP-ALL after matching for relevant prognostic parameters. It undoubtedly characterizes genetically an ALL entity associated with established favorable prognostic parameters. High-risk therapeutic procedures such as allogeneic SCT should be considered restrictively.
Seeger
K
K
Department of Pediatric Oncology/Hematology, Charité Medical Center, Humboldt-University, Berlin, Germany. karl.seeger@charite.de
von Stackelberg
A
A
Taube
T
T
Buchwald
D
D
Körner
G
G
Suttorp
M
M
Dörffel
W
W
Tausch
W
W
Henze
G
G
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D050676:Core Binding Factor Alpha 2 Subunit; D005260:Female; D005819:Genetic Markers; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016555:Matched-Pair Analysis; D015999:Multivariate Analysis; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D011379:Prognosis; D016016:Proportional Hazards Models; D012008:Recurrence; D012306:Risk; D015996:Survival Rate; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D005819:Genetic Markers; D015514:Oncogene Proteins, Fusion; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein