Although cancer is among the leading causes of death in children, only approximately 6550 new cases are diagnosed each year in children less than 15 years of age in the United States. Thus, most pediatricians are unlikely to diagnose cancer in a child in their clinical practice. At the same time, major progress in the treatment of children with cancer has been made in the last decades. Indeed, more than 50% to 60% of children diagnosed with cancer are likely to become prolonged survivors, and most will be cured of their malignancy. Accordingly, it has been estimated that in 1990, 1 of every 1000 young adults reaching the age of 20 will be a survivor of childhood cancer.