Worldwide, it is estimated that childhood cancer has an incidence of more than 175,000 per year, and a mortality rate of approximately 96,000 per year.[4] In developed countries, childhood cancer has a mortality of approximately 20% of cases.[5] In low resource settings, on the other hand, mortality is approximately 80%, or even 90% in the world's poorest countries.[5] In many developed countries the incidence is slowly increasing, as rates of childhood cancer increased by 0.6% per year between 1975 and 2002 in the United States[6] and by 1.1% per year between 1978 and 1997 in Europe.[7]