Improved survival for children and adolescents with acute lymphoblastic leukemia between 1990 and 2005: a report from the children's oncology group

Abstract

Purpose: To examine population-based improvements in survival and the impact of clinical covariates on outcome among children and adolescents with acute lymphoblastic leukemia (ALL) enrolled onto Children's Oncology Group (COG) clinical trials between 1990 and 2005.

Patients and methods: In total, 21,626 persons age 0 to 22 years were enrolled onto COG ALL clinical trials from 1990 to 2005, representing 55.8% of ALL cases estimated to occur among US persons younger than age 20 years during this period. This period was divided into three eras (1990-1994, 1995-1999, and 2000-2005) that included similar patient numbers to examine changes in 5- and 10-year survival over time and the relationship of those changes in survival to clinical covariates, with additional analyses of cause of death.

Results: Five-year survival rates increased from 83.7% in 1990-1994 to 90.4% in 2000-2005 (P < .001). Survival improved significantly in all subgroups (except for infants age ≤ 1 year), including males and females; those age 1 to 9 years, 10+ years, or 15+ years; in whites, blacks, and other races; in Hispanics, non-Hispanics, and patients of unknown ethnicity; in those with B-cell or T-cell immunophenotype; and in those with National Cancer Institute (NCI) standard- or high-risk clinical features. Survival rates for infants changed little, but death following relapse/disease progression decreased and death related to toxicity increased.

Conclusion: This study documents ongoing survival improvements for children and adolescents with ALL. Thirty-six percent of deaths occurred among children with NCI standard-risk features emphasizing that efforts to further improve survival must be directed at both high-risk subsets and at those children predicted to have an excellent chance for cure.

Conflict of interest statement

Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.

Figures

Fig 1.

Overall survival probability by treatment era for patients enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005.

Fig A1.

Overall survival probability for patients with acute lymphoblastic leukemia of different ages enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005; (A) infants age ≤ 1 year, and persons age (B) 1 to 9.99 years, (C) 10 years or older, and (D) 15 years or older.

Fig A2.

Overall survival probability for (A) males and (B) females enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005.

Fig A3.

Overall survival probability for (A) whites, (B) blacks, and (C) persons of other ethnicities enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005.

Fig A4.

Overall survival probability for persons who reported themselves as (A) Hispanic, (B) non-Hispanic, or (C) unknown ethnicity enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005.

Fig A5.

Overall survival probability by leukemia immunophenotype for patients with (A) B-cell and (B) T-cell acute lymphoblastic leukemia enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005.

Fig A6.

Overall survival probability by National Cancer Institute risk group for patients with (A) standard-risk (age 1-9.99 years and initial WBC count 50,000/μL) acute lymphoblastic leukemia enrolled onto Children's Oncology Group trials in 1990-1994, 1995-1999, and 2000-2005.

Fig A7.

Survival tree regression analysis was performed by using complete data for (A) patients older than age 1 year (yr); and (B) infants age ≤ 1 year. NCI, National Cancer Institute; OS, overall survival.