Long-term survival increases in children with acute lymphoblastic leukemia

Five-year survival for acute lymphoblastic leukemia (ALL) among children and adolescents treated through Children's Oncology Group (COG) clinical trials increased from 83.7% from 1990 to 1994 to 90.4% from 2000 to 2005, according to a study showing similar gains in 10-year survival. The researchers credited the advances to treatment that comes as part of rigorous clinical trials.

Researchers analyzed data on 21,626 patients aged 0 to 22 years enrolled in COG ALL clinical trials from 1990 to 2005, subdivided into 3 eras of 1990 to 1994, 1995 to 1999, and 2000 to 2005, in order to examine changes in 5-year and 10-year survival over time and the relationship of those changes in survival to clinical covariates, with additional analyses of cause of death.

In addition to gains in 5-year survival, 10-year survival increased from 80.1% from 1990 to 1994 to 83.9% from 1995 to 1999. Survival improved significantly in younger children and adolescents; white, black, Hispanic, and non-Hispanic children; those with B-precursor ALL and T-cell ALL; and those with standard-risk or high-risk disease.

However, 5-year survival among infants aged 1 year and younger changed little from 1990 to 1994 (52.1%) and from 2000 to 2005 (50.3%), while the causes of death changed considerably. Death rates from ALL relapse or progression decreased from 43% from 1990 to 1994 to 27.2% from 2000 to 2005, while the cumulative incidence of treatment-related deaths increased from 3.9% from 1990 to 1994 to 13.9% from 2000 to 2005.

Researchers noted that 36% of deaths occurred among children with National Cancer Institute standard-risk features, and they emphasized 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.

"New drugs and new drug combinations have increased survival rates and helped children live longer and better, and we continue to refine these therapies,” said lead researcher Stephen Hunger, MD, professor of pediatrics at the University of Colorado School of Medicine and director of the Center for Cancer and Blood Disorders at Children’s Hospital Colorado. “Nevertheless, we still have important work to do to help the remaining 10% of patients who don't survive."

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