1. From the Children's Oncology Group, Statistics and Data Center, Arcadia, CA; Tampa Children's Hospital, Tampa; Children's Oncology Group, Statistics and Data Center, University of Florida, Gainesville, FL; University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA; St Jude Children's Research Hospital, Memphis, TN; University of Rochester Medical Center, Rochester, NY; Children's Hospital, Los Angeles, CA; and Brown Medical School, Providence, RI