Trends in cancer incidence among children in the U.S.

BACKGROUND: This report provides results of an analysis of temporal trends in childhood cancer incidence in the U.S. stratfied by age, sex, and to a lessor extent, race, within common histologic subtypes. METHODS: Population-based data from nine registries of the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute were analyzed. The analysis was limited to children age < or = 14 years. Cancer cases were restricted to those patients with a malignant neoplasm diagnosed between 1974 and 1991; more than 12,000 children were included. Average annual percentage change in incidence rates and corresponding 95% confidence intervals were estimated from the maximum likelihood method of Poisson regression. RESULTS: Among children age < or = 14 years there was a 1% average yearly increase (95% CI 0.6, 1.3) in the incidence rates of all malignant neoplasms combined. The average annual percentage change was similar for males and females, and slightly higher for black children compared with white children. Rates increased an average of 2% or more per year for astroglial tumors, rhabdomyosarcomas, germ cell tumors, and osteosarcomas. The average annual percentage change for acute lymphoid leukemia was 1.6% and trends were somewhat stronger for blacks than whites. Cancer trends, in general, were strongest in young children. In particular, increases in astroglial tumors and rhabdomyosarcomas were most apparent among children age < 3 years, and for retinoblastoma and neuroblastoma among children in their first year of life. The average annual percentage change for acute lymphoid leukemia did not vary dramatically with age, however children age < 2 years had stronger trends compared with older children. We found little evidence for increasing trends in Wilms' tumor, primitive neuroectodermal tumors, or hematopoietic neoplasms other than acute lymphoid leukemia. CONCLUSIONS: These results suggest that cancer occurrence among children within specific histologies increased modestly in the U.S. between 1974 and 1991, and that the increases were most apparent among young children.