Obesity and survival in a cohort of predominantly Hispanic children with acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL), the most common malignancy in children, constitutes 25% of all pediatric cancer. Childhood cancer patients who are obese at diagnosis represent a particular challenge for the oncologist. Obesity may complicate chemotherapy dose determination, and has been associated with decreased overall and event-free survival in a number of adult cancer patients, and more recently in pediatric patients. The purpose of the present study was to examine whether obesity at diagnosis was associated with decreased overall and event-free survival in a cohort of 322 predominantly Hispanic pediatric patients with B-precursor ALL. Obesity was classified as an age-standardized and sex-standardized body mass index z-score at or above the 95th percentile. Hazard ratios (HRs) for overall and event-free survival were assessed using Cox proportional hazards regression modeling. Obesity at diagnosis was not associated with decreased overall survival (HR = 1.40, 95% confidence interval = 0.69-2.87) or event-free survival (HR = 1.08, 95% confidence interval = 0.65-1.82) in the overall cohort or in either of the 2 age-at-diagnosis (2 to 9y; 10 to 18y) subgroups. Our finding of no obesity-related prognostic effect in the overall cohort and in the under 2 to 9-year age-at-diagnosis cohort was consistent with the previous large-scale study of ALL patients; the absence of a prognostic effect in the 10 to 18-year age-at-diagnosis cohort, however, conflicted with previous findings.