Outcomes for children and adolescents with cancer: challenges for the twenty-first century

Abstract

Purpose: This report provides an overview of current childhood cancer statistics to facilitate analysis of the impact of past research discoveries on outcome and provide essential information for prioritizing future research directions.

Methods: Incidence and survival data for childhood cancers came from the Surveillance, Epidemiology, and End Results 9 (SEER 9) registries, and mortality data were based on deaths in the United States that were reported by states to the Centers for Disease Control and Prevention by underlying cause.

Results: Childhood cancer incidence rates increased significantly from 1975 through 2006, with increasing rates for acute lymphoblastic leukemia being most notable. Childhood cancer mortality rates declined by more than 50% between 1975 and 2006. For leukemias and lymphomas, significantly decreasing mortality rates were observed throughout the 32-year period, though the rate of decline slowed somewhat after 1998. For remaining childhood cancers, significantly decreasing mortality rates were observed from 1975 to 1996, with stable rates from 1996 through 2006. Increased survival rates were observed for all categories of childhood cancers studied, with the extent and temporal pace of the increases varying by diagnosis.

Conclusion: When 1975 age-specific death rates for children are used as a baseline, approximately 38,000 childhood malignant cancer deaths were averted in the United States from 1975 through 2006 as a result of more effective treatments identified and applied during this period. Continued success in reducing childhood cancer mortality will require new treatment paradigms building on an increased understanding of the molecular processes that promote growth and survival of specific childhood cancers.

Fig 1.

Incidence rates for all cancers combined, cancers other than CNS and lymphoid leukemia, lymphoid leukemia, and brain and CNS cancers among children younger than 20 years of age, according to data from Surveillance, Epidemiology, and End Results 9 (SEER 9) Registries, 1975 through 2006. (*) The slope of the join point regression trend line is significantly different from zero (P ≤ .05). The 95% CIs of annual percentage changes (APCs) are presented in Table 1.

Fig 2.

Age-specific mortality trends for all malignant cancers combined among children younger than 20 years of age in the United States from 1975 through 2006. An estimated 38,032 childhood malignant cancer deaths were averted from 1975 through 2006, assuming the 1975 baseline rate persisted through 2006. (*) The slope of the join point segment is statistically different from zero (P ≤ .05). APC, annual percentage change.

Fig 3.

United States age-adjusted childhood mortality trends for lymphoma and leukemia, and all other cancer sites combined, with annual percentage changes (APCs) for join point segments for males and females younger than 20 years of age, from 1975 though 2006. (*) The slope of the regression line significantly differs from zero; P < .05.

Fig 4.

Five-year survival rates for all cancers combined in children by age group and period of diagnosis from 1975 to 2002, with follow-up of vital status through 2006, according to data from the Surveillance, Epidemiology, and End Results 9 (SEER 9) Registries.

Fig 5.

Five-year survival rates for (A) acute lymphoblastic leukemia, (B) acute myeloid leukemia, (C) non-Hodgkin's lymphoma, and (D) Hodgkin's lymphoma among children by age group and period of diagnosis, 1975 through 2002, with follow-up of vital status through 2006, according to data from Surveillance, Epidemiology, and End Results 9 (SEER 9) Registries.

Fig 6.

Five-year survival rates for (A) medulloblastoma and other CNS tumors, (B) CNS tumors other than medulloblastoma, and (C) medulloblastoma among children by age group and period of diagnosis from 1975 through 2002, with follow-up of vital status through 2006, according to data from the Surveillance, Epidemiology, and End Results 9 (SEER 9) Registries. Medulloblastoma survival rates for the 15- to 19-year-old age group were suppressed when there were < 25 patients during the time period.

Fig 7.

Five-year survival rates for (A) osteosarcoma, (B) Ewing sarcoma, and (C) rhabdomyosarcoma among children by age group and time period of diagnosis from 1975 through 2002, with follow-up of vital status through 2006, according to data from Surveillance, Epidemiology, and End Results 9 (SEER 9) registries.

Fig 8.

Five-year survival rates for (A) non-CNS germ cell tumors, (B) Wilms tumors, and (C) neuroblastoma among children by age group and time period of diagnosis from 1975 through 2002, with follow-up of vital status through 2006, according to data from Surveillance, Epidemiology, and End Results 9 (SEER 9) registries.