Post-induction residual disease in translocation t(12;21)-positive childhood ALL.
BACKGROUND
t(12;21)(p1 3;q22), the most frequent chromosomal translocation found in childhood acute lymphoblastic leukemia (ALL), occurs in approximately 25% of B-lineage ALL cases and has been claimed to carry a good prognosis.


METHODS
As part of the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL-MRD 95 study, which includes children from Iceland, Norway, and Denmark diagnose d with ALL, patients were screened for the presence of t(12; 21) by reverse transcriptase-polymerase chain reaction (RT-PCR) at diagnosis, and their residual disease was quantified after 4 weeks of induction therapy (prednisolone, vincristine, doxorubicin, i.t. methotrexate) by a competitive, clone-specific, semi-nested PCR analysis.


RESULTS
Among 96 children diagnosed with ALL, and quantified for post induction residual disease, 32 were t(12;21)-positive. The median residual disease was similar for B-precursor ALL patients with and without t(12;21) (0.009 vs. 0.03%, P = 0.12).


CONCLUSIONS
Al though patients with t(12;21)-positive ALL have been claimed to have a good outcome, these data indicate that this does not reflect a high sensitivity to prednisolone, vincristine, and doxorubicin given during induction therapy.
Seyfarth
Jeanette
J
Department of Clinical Immunology, The National University Hospital, Rigshospitalet, Copenhagen, Denmark.
Madsen
Hans O
HO
Nyvold
Charlotte
C
Ryder
Lars P
LP
Clausen
Niels
N
Jonmundsson
Gudmundur K
GK
Wesenberg
Finn
F
Schmiegelow
Kjeld
K
D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D050676:Core Binding Factor Alpha 2 Subunit; D017931:DNA Primers / Q000737:chemistry; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage; D018365:Neoplasm, Residual / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D011239:Prednisolone / Q000008:administration & dosage; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D012074:Remission Induction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014178:Translocation, Genetic; D014750:Vincristine / Q000008:administration & dosage; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D017931:DNA Primers; D004317:Doxorubicin; D008727:Methotrexate; D015514:Oncogene Proteins, Fusion; D011239:Prednisolone; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014750:Vincristine; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein