Lymphoblast biology and outcome among children with Down syndrome and ALL treated on CCG-1952.
BACKGROUND
Patients with Down syndrome (DS) and standard risk (SR) acute lymphoblastic leukemia (ALL-DS) are reported to have inferior event free (EFS) and overall survival (OS) compared to patients without DS (ALL-NDS).


METHODS
We compared the prevalence of favorable and unfavorable clinical and biologic features, toxicity and outcome within the ALL-DS and ALL-NDS cohorts of 2,174 eligible patients with SR-ALL enrolled on CCG-1952.


RESULTS
Fifty-nine patients (3%) had ALL-DS. DS patients were less likely to have either favorable (hyperdiploidy, triple trisomy of chromosomes 4, 10, and 17, TEL-AML1 rearrangement) or unfavorable (T-cell ALL, hypodiploidy, adverse translocations) biologic features. Toxicity occurred significantly more often and number of days hospitalized was significantly greater in ALL-DS than in ALL-NDS. ALL-DS patients had an inferior 4-year EFS compared to the NDS cohort. However, EFS was equivalent when the comparison excluded ALL-NDS with favorable biologic features. OS was significantly inferior for ALL-DS.


CONCLUSIONS
The absence of favorable biologic features within ALL-DS contributes to the difference in EFS previously observed between DS and NDS SR-ALL cohorts.
Bassal
Mylène
M
Pediatric Hematology/Oncology/BMT, University of Colorado Health Sciences Center, Denver, Colorado, USA. bassal.mylene@tchden.org
La
Mei K
MK
Whitlock
James A
JA
Sather
Harland N
HN
Heerema
Nyla A
NA
Gaynon
Paul S
PS
Stork
Linda C
LC
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D004314:Down Syndrome / Q000150:complications*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011003:Ploidies; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications / Q000188:drug therapy* / Q000473:pathology*; D011379:Prognosis; D016896:Treatment Outcome