Longitudinal changes in obesity and body mass index among adult survivors of childhood acute lymphoblastic leukemia: A report from the Childhood Cancer Survivor Study

Purpose We examined the rate of increase in the body mass index (BMI; kg/m(2)) after final height attainment in survivors of acute lymphoblastic leukemia (ALL) and a noncancer comparison group. Methods Childhood Cancer Survivor Study (CCSS) is a retrospectively ascertained cohort study that prospectively tracks the health status of adults who were diagnosed with childhood cancer between 1970 and 1986 and a comparison group of siblings. Changes in BMI from baseline enrollment to time of completion of follow-up (mean interval, 7.8 years) were calculated for 1,451 ALL survivors (mean age, 32.3 years at follow-up) and 2,167 siblings of childhood cancer survivors (mean age, 35.9 years). Results The mean BMI of the CCSS sibling comparison group increased with age (women, 0.25 units/yr, 95% CI, 0.22 to 0.28 units; men, 0.23 units/yr, 95% CI, 0.20 to 0.25 units). Compared with CCSS siblings, ALL survivors who were treated with cranial radiation therapy (CRT) had a significantly greater increase in BMI (women, 0.41 units/yr, 95% CI, 0.37 to 0.45 units; men, 0.29 units/yr; 95% CI, 0.26 to 0.32 units). The rate of BMI increase was not significantly increased for ALL survivors who were treated with chemotherapy alone. Younger age at CRT exposure significantly modified risk. Conclusion CRT used in the treatment of childhood ALL is associated with a greater rate of increasing BMI, particularly among women treated with CRT during the first decade of life. Health care professionals should be aware of this risk and interventions to reduce or manage weight gain are essential in this high-risk population.