Mortality in overweight and underweight children with acute myeloid leukemia

Current treatment for acute myeloid leukemia (AML) in children cures about half the patients. Of the other half, most succumb to leukemia, but 5% to 15% die of treatment-related complications. Overweight children with AML seem to experience excess life-threatening and fatal toxicity. Nothing is known about how weight affects outcomes in pediatric AML.

To compare survival rates in children with AML who at diagnosis are underweight (body mass index [BMI] < or =10th percentile), overweight (BMI > or =95th percentile), or middleweight (BMI = 11th-94th percentiles).

Retrospective review of BMI and survival in 768 children and young adults aged 1 to 20 years enrolled in Children's Cancer Group-2961, an international cooperative group phase 3 trial for previously untreated AML conducted August 30, 1996, through December 4, 2002. Data were collected through January 9, 2004, with a median follow-up of 31 months (range, 0-78 months).

Hazard ratios (HRs) for survival and treatment-related mortality.

Eighty-four of 768 patients (10.9%) were underweight and 114 (14.8%) were overweight. After adjustment for potentially confounding variables of age, race, leukocyte count, cytogenetics, and bone marrow transplantation, compared with middleweight patients, underweight patients were less likely to survive (HR, 1.85; 95% confidence interval [CI], 1.19-2.87; P = .006) and more likely to experience treatment-related mortality (HR, 2.66; 95% CI, 1.38-5.11; P = .003). Similarly, overweight patients were less likely to survive (HR, 1.88; 95% CI, 1.25-2.83; P = .002) and more likely to have treatment-related mortality (HR, 3.49; 95% CI, 1.99-6.10; P<.001) than middleweight patients. Infections incurred during the first 2 courses of chemotherapy caused most treatment-related deaths.

Treatment-related complications significantly reduce survival in overweight and underweight children with AML.