1. ¹Department of Pathology, All Children's Hospital, St Petersburg, FL, USA
2. ²Department of Pediatrics, University of South Florida, Tampa, FL, USA
3. ³Children's Oncology Group Research Data Center, and Department of Statistics, University of Florida, Gainesville, FL, USA
4. ⁴Department of Preventative Medicine, University of Southern California, Los Angeles, CA, USA
5. ⁵MidWest Children's Cancer Center, Department of Pediatrics, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, USA
6. ⁶University of Mississippi Medical Center, Jackson, MS, USA
7. ⁷British Columbia's Children's Hospital, University of British Columbia, Vancouver, BC, Canada
8. ⁸Department of Pathology, John Hopkins University, Baltimore, MD, USA
9. ⁹Department of Hematology-Oncology, Children's Hospital, Los Angeles, CA, USA
10. ¹⁰Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
11. ¹¹Department of Pathology, The Ohio State University, Columbus, OH, USA

Correspondence: MJ Sutcliffe, c/o Donna Correia, Publications Coordinator, Children's Oncology Group, PO Box 60012, Arcadia, CA 91066-6012, USA. Fax: +1 626 445 4334; E-mail: dcorreia@childrensoncologygroup.org

Received 26 March 2004; Accepted 23 December 2004; Published online 24 March 2005.

Abstract

Chromosome aberrations have a major role in pediatric acute lymphoblastic leukemia (ALL) risk assignment. The Children's Cancer Group (CCG) and the Pediatric Oncology Group (POG) independently assessed the significance of trisomy for chromosomes 4, 10, and 17 in National Cancer Institute (NCI) Standard- and High-Risk ALL. Data from 1582 (CCG) and 3902 (POG) patients were analyzed. Eight-year event-free survivals (EFS) of 91% (CCG) and 89% (POG) (P<0.001) were achieved in patients assigned to NCI Standard Risk whose leukemic cells had simultaneous trisomies 4, 10, and 17. Both groups showed the degree of favorable prognostic importance increased with the actual number of favorable trisomies. POG analyses also demonstrated hyperdiploidy (53 chromosomes) was less of an independently significant prognostic factor in the absence of these key trisomies. This finding supported conclusions from previous CCG and POG studies that specific trisomies are more important than chromosome number in predicting outcome in pediatric B-precursor ALL. In NCI Higher Risk patients, the number of favorable trisomies was not prognostically significant, but showed the same trend. Moreover, specific trisomies 4, 10, and 17 remain associated with favorable prognosis in Standard-Risk B-precursor ALL, even in the context of very different treatment approaches between the groups.