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

Abstract

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.

Fig 1.

Model-based estimates of linear changes in mean body mass index between baseline and 10 years follow-up for (A) female Childhood Cancer Survivor Study (CCSS) sibling controls and adult survivors of childhood acute lymphoblastic leukemia (ALL) according to treatment; (B) male CCSS siblings and adult survivors according to treatment; (C) female CCSS sibling controls and adult survivors who received cranial radiation therapy (CRT) ≥ 20 Gy according to age at diagnosis of ALL; (D) male CCSS sibling controls and adult survivors who received CRT ≥ 20 Gy, according to age at diagnosis of ALL. The P values are from testing the equality of slope to the CCSS sibling controls (only those with P < .05 are shown).