In the five years since publication of the second edition of Childhood Leukemias, new insights into the molecular and cellular biology of cancers in general, and of the leukemias in particular, have catalyzed exciting advances in diagnostic methods, strategies of risk assessment, and the development of targeted and other novel forms of treatment. Encouraged by this progress, and the enthusiastic responses of readers of the previous edition, I willingly accepted the invitation to develop a third edition of this successful book.

The rapid growth in our understanding of the biology of childhood leukemias and the accelerating pace of innovations in diagnostic and therapeutic approaches presented a considerable challenge during revision of the second edition. As you will notice, each chapter has been extensively modified or rewritten to accommodate the most recent information and references. Although structured to emphasize emerging themes in leukemia pathobiology and treatment, the reworked book still seeks to maintain a balance between fundamental pathophysiology and practical approaches to patient management, a standard that was central to the success of our earlier editions. Three chapters are entirely new. One deals with the epigenetics of leukemia, a topic that has moved rapidly to the fore of leukemia research. The discovery that aberrant epigenetic changes often cooperate with DNA sequence alterations in the initiation and progression of cancer, and that such changes are potentially reversible, has already led to clinical trials of therapies based on key epigenetic findings. Another addition focuses on leukemias in children with Down syndrome, calling attention to the pathobiology that underlies the increased incidence and complications of this problematic disease presentation. Finally, there is a new chapter on the treatment of adolescents and young adults with acute lymphoblastic leukemia – a group that historically has had a much worse prognosis than younger patients.