1. Leukemia Service, Memorial Sloan-Kettering Cancer Center, New York, NY;
2. New York State Cancer Registry, NY State Department of Health, Albany, NY;
3. Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY;
4. Northwestern University, Feinberg School of Medicine, Chicago, IL; and
5. Rambam Medical Center, Technion, Haifa, Israel