The first volume of the International Incidence of Childhood Cancer clearly fulfilled an important need among researchers and clinicians and rapidly established itself as the standard reference on incidence between different geographic locations and ethnic groups within them. This second volume compares the incidence results and evaluation of temporal trends for most of the cancer types. Childhood neoplasms are classified according to a special scheme, relying principally on the cell of origin of the tumour, rather than on anatomical location. This is particularly appropriate for cancers which are distinguished primarily by the particular cell affected by a specific mutation. This classification scheme has become widely adopted for epidemiological (and clinical) studies of childhood cancer. This is another welcome development, which serves to enhance the validity of comparative studies of incidence and clinical outcome. This volume includes data from several cancer registries and countries.