Cancer is the second most common cause of death after accidents among children in developed countries. Meanwhile, in developing countries, improvements in the control of communicable diseases and the occurrence of premature delivery may lead to the emergence of cancer in children as a greater public health problem than in the past. The rationale for considering childhood cancers separately from cancers in adults is that there are differences in the sites of occurrence, in the histological appearance, and in their clinical behavior. Although specific types of childhood cancer are uncommon, collectively they represent an important public health problem. This book provides a unique compilation and evaluation of data on the occurrence and causes of childhood cancer.