Acute lymphoblastic leukaemia (ALL) is the most frequent childhood cancer. During the last 50 years its prognosis has improved from zero probability of survival in the 1950s to more than 80% chance to be cured at the beginning of the 21st century.
ALL is a highly chemosensitive disease and its successful treatment is a good indicator of the level of medical care that children with cancer get in each country. Th ere are huge diff erences in the outcome of this disease between developed and developing countries.