(HealthDay News) — Induction failure in pediatric acute lymphoblastic leukemia (ALL) is characterized by biologic and clinical heterogeneity, according to a study published in the April 12 issue of the New England Journal of Medicine.
Martin Schrappe, M.D., from the Christian-Albrechts-University in Kiel, Germany, and colleagues investigated disease characteristics, treatments administered, and outcomes of induction failure in 1,041 of 44,017 patients, aged 0 to 18 years of age, with newly diagnosed ALL.
The researchers found that patients with induction failure often presented with high-risk features, which included older age, high leukocyte count, Philadelphia chromosome, 11q23 rearrangement, and T-cell phenotype. The estimated 10-year survival rate was 32 ± 1 percent, during a median follow-up of 8.3 years. Characteristics associated with particularly poor outcome included age 10 years or older, T-cell leukemia, 11q23 rearrangement, and 25 percent or more blasts in the bone marrow at the end of induction therapy. For patients with precursor B-cell leukemia, an age of 1 to 5 years and high hyperdiploidy were linked with favorable outcomes. In T-cell leukemia, there were improved outcomes for those who underwent allogeneic stem-cell transplantation from matched, related donors. For children younger than 6 years with precursor B-cell leukemia, and without adverse genetic features, treatment with chemotherapy alone was associated with a 10-year survival rate of 72 ± 5 percent.
“Induction failure is rare, occurring in only 2 to 3 percent of all patients, but it constitutes one of the most unfavorable outcomes in pediatric ALL,” the authors write. “In our large retrospective series of patients with induction failure, we observed great clinical and biologic heterogeneity.”
Several authors disclosed financial relationships with pharmaceutical and biotechnology companies.