Cancer Surveillance Series: Recent Trends in Childhood Cancer Incidence and Mortality in the United States

Background: Public concern about possible increases in childhood cancer incidence in the United States led us to examine recent incidence and mortality patterns. Methods: Cancers diagnosed in 14 540 children under age 15 years from 1975 through 1995 and reported to nine population-based registries in the National Cancer Institute's Surveillance, Epidemiology, and End Results Program were investigated. Ageadjusted incidence was analyzed according to anatomic site and histologic categories of the International Classification of Childhood Cancer. Ageadjusted U.S. mortality rates were calculated. Trends in rates were evaluated by use of standard regression methods. Results: A modest rise in the incidence of leukemia, the most common childhood cancer, was largely due to an abrupt increase from 1983 to 1984; rates have decreased slightly since 1989. For brain and other central nervous system (CNS) cancers, incidence rose modestly, although statistically significantly (two-sided P = .020), largely from 1983 through 1986. A few rare childhood cancers demonstrated upward trends (e.g., the 40% of skin cancers designated as dermatofibrosarcomas, adrenal neuroblastomas, and retinoblastomas, the latter two in infants only). In contrast, incidence decreased modestly but statistically significantly for Hodgkin's disease (twosided P = .037). Mortality rates declined steadily for all major childhood cancer categories, although less rapidly for brain/CNS cancers. Conclusions: There was no substantial change in incidence for the major pediatric cancers, and rates have remained relatively stable since the mid-1980s. The modest increases that were observed for brain/CNS cancers, leukemia, and infant neuroblastoma were confined to the mid-1980s. The patterns suggest that the increases likely reflected diagnostic improvements or reporting changes. Dramatic declines in childhood cancer mortality represent treatment-related improvements in survival. J Natl Cancer Inst 1999;91:1051-8 porate the new codes introduced in ICD-O-2 (12), and designated as the ICCC (11). In preparation for forthcoming NCI and International Agency for Research on Cancer monographs that present childhood cancer incidence data from the United States and around the world, respectively, all pediatric cancers registered in the SEER Program were recently classified according to the ICCC.