Abstract
BACKGROUND: We aimed to characterize body composition, metabolic impairments, and physical performance among survivors of pediatric abdominal and pelvic solid tumors. METHODS: Participants included 431 survivors of abdominal or pelvic tumors [median attained age = 29.9 (range: 18.7-55.1) years]. Relative lean mass and fat mass were assessed with dual X-ray absorptiometry. Metabolic outcomes [insulin resistance (IR), high-density lipoprotein (HDL), low-density lipoprotein, and triglycerides] were based on laboratory values and medication usage. General linear regression evaluated associations between treatment and lifestyle with body composition; binomial regression evaluated associations between body composition and metabolic outcomes and physical performance. RESULTS: Lean mass was lower than values from the National Health and Nutrition Examination Survey (NHANES) in males (Z-score = -0.67 ± 1.27; P < 0.001) and females (Z-score = -0.72 ± 1.28; P < 0.001). Higher cumulative abdominal and pelvic radiation doses were associated with lower lean mass among males [abdominal: β = -0.22 (SE) ± 0.07; P = 0.002 and pelvic: β = -0.23 ± 0.07; P = 0.002] and females (abdominal: β = -0.30 ± 0.09; P = 0.001 and pelvic: β = -0.16 ± 0.08; P = 0.037). Prevalence of IR (40.6% vs. 33.8%; P = 0.006), low HDL (28.9% vs. 33.5%; P = 0.046), and high triglycerides (18.4% vs. 10.0%; P < 0.001) was increased among survivors relative to NHANES. Compared with survivors with normal/high lean mass and normal/low fat mass, survivors with normal/high lean mass and high fat mass had an increased risk of IR (P < 0.001), low HDL (P < 0.001), reduced quadriceps strength at 60°/second (P < 0.001) and 300°/second (P < 0.001), and reduced distance covered in the 6-minute walk (P < 0.01). CONCLUSIONS: Abdominal/pelvic radiotherapy is associated with body composition changes that can adversely influence metabolic outcomes and performance status among survivors. IMPACT: Interventions targeting body composition may facilitate management of cardiovascular disease risk in this population.