[1341] Association of Aneuploidy with High S-Phase in T-Acute Lymphoblastic Leukemia of Childhood.

Jyothilekshmi Pillai, Loris McGavran, Karen Swissheim, Xiayuan Liang. The Children's Hospital, Aurora, CO; University of Colorado Denver School of Medicine, Aurora

Background: T-acute lymphoblastic leukemia (T-ALL) is less common and clinically more aggressive than B-ALL in pediatric patients. It has been well known that the chromosomal aneuploidy plays an important role in prognosis of B-ALL of childhood. S-phase fraction (SPF) is an indicator of cell proliferation. Previous study shows that SPF often markedly elevates in B-ALL with hypodiploidy. However, it is unknown if chromosomal aneuploidy has any impact on T-ALL or association with SPF. We investigated the association of chromosomal ploidy with SPF and cerebrospinal fluid (CSF) involvement in a series of T-ALL of pediatric patients.
Design: 60 cases of newly diagnosed T-ALL at The Children's Hospital, Colorado from 1996 to 2010 which had a complete karyotype, SPF, and CSF data available were examined. SPF was analyzed by flow cytometry. SPF >10% was defined as high SPF. We compared frequencies of high SPF and CSF involvement between the diploid (Chromosome # =46. Pseudodiploidy is defined as structural abnormality in any of 46 chromosomes) group and the aneupolid (46 < chromosome # < 46) group.
Results: The cases with aneuploidy more frequently have a high cell proliferation rate than the cases with diploidy. The difference is statistically significant. In addition, the aneuploid cases, especially the cases with hypodiploidy are more frequently positive for CSF involvement.

  # of CasesS-phase (> 10%)P valueCSF+P value
DiploidyNormal karyotype204/18 (22%) 4/19 (21%) 
 Peudodiploidy274/24 (17%) 7/26 (27%) 
 Total478/42 (19%) 11/45 (24%) 
AneuploidyHypodiploidy53/5 (60%) 3/4 (75%)0.065
 Hyperdiploidy83/5 (60%) 2/8 (25%) 
 Total137/12 (58%)0.01255/12 (42%)0.29

Conclusions: Aneuploid chromosomal abnormalities are associated with a high cell proliferation rate; and the cases with hypodiploid karyotypes appear more frequently to have CSF involvement. These findings suggest that aneuploid karytotype may play an important role in aggressive behavior and unfavorable outcome among T-ALLs of childhood.
Category: Hematopathology

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 162, Wednesday Morning


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