Association between body mass index at diagnosis and outcomes in Chinese children with newly diagnosed acute lymphoblastic leukemia.

ABSTRACT

PURPOSE: Studies of the association between body mass index (BMI) at diagnosis and treatment outcome in children with acute lymphoblastic leukemia (ALL) have yielded inconsistent results. Hence, we conducted a retrospective study in a large cohort of Chinese children with ALL treated with contemporary protocols. PATIENTS AND METHODS: A total of 1437 children (62.1% male; median age at diagnosis 5.7 years, range 2.3-16.3 years) were enrolled in two consecutive clinical trials at the Shanghai Children's Medical Center. The rates of overall survival, event-free survival, relapse, treatment-related mortality, and adverse events were compared among patients who were underweight (BMI < 5th percentile), at a healthy weight (5th to 85th percentile), overweight (>85th to <95th percentile), and obese (≥95th percentile). RESULTS: At diagnosis, 91 (6.3%) patients were underweight, 1070 (74.5%) were at a healthy weight, 91 (6.3%) were overweight, and 185 (12.9%) were obese. No significant association was found between weight status and 5-year overall survival, event-free survival, or relapse in the overall cohort. When analyzed as a continuous variable, a higher BMI Z-score was associated with treatment-related mortality (hazard ratio 1.33 (95% confidence interval [CI], 1.05-1.68%), p = 0.02). The treatment-related mortality rate was higher in the overweight (5.5%, 95% CI 0.8-10.2%) and obese (3.2%, 95% CI 0.6-5.8%) groups compared with the underweight (0.0%) and healthy-weight groups (1.9%, 95% CI 1.1-2.7%; p = 0.04). Multivariable analysis showed that children who were overweight had a higher risk of treatment-related mortality (hazard ratio 3.8, 95% CI 1.3-11.4). CONCLUSION: While body weight status was not associated with event-free survival or overall survival, overweight patients were at higher risk of treatment-related mortality.