Abdominal Radiotherapy: A Major Determinant of Metabolic Syndrome in Nephroblastoma and Neuroblastoma Survivors

BACKGROUND Reports on metabolic syndrome in nephroblastoma and neuroblastoma survivors are scarce. Aim was to evaluate the occurrence of and the contribution of treatment regimens to the metabolic syndrome. PATIENTS AND METHODS In this prospective study 164 subjects participated (67 adult long-term nephroblastoma survivors (28 females), 36 adult long-term neuroblastoma survivors (21 females) and 61 control subjects (28 females)). Controls were recruited cross-sectionally. Waist and hip circumference as well as blood pressure were measured. Body composition and abdominal fat were assessed by dual energy X-ray absorptiometry (DXA-scan). Laboratory measurements included fasting triglyceride, high density lipoprotein-cholesterol (HDL-C), glucose, insulin, low-density lipoprotein-cholesterol (LDL-C) and free fatty acids (FFA) levels. RESULTS Median age at follow-up was 30 (range 19-51) years in survivors and 32 (range 18-62) years in controls. Median follow-up time in survivors was 26 (6-49) years. Nephroblastoma (OR = 5.2, P<0.0001) and neuroblastoma (OR 6.5, P<0.001) survivors had more components of the metabolic syndrome than controls. Survivors treated with abdominal irradiation had higher blood pressure, triglycerides, LDL-C, FFA and lower waist circumference. The latter can not be regarded as a reliable factor in these survivors as radiation affects the waist circumference. When total fat percentage was used as a surrogate marker of adiposity the metabolic syndrome was three times more frequent in abdominally irradiated survivors (27.5%) than in non-irradiated survivors (9.1%, P = 0.018). CONCLUSIONS Nephroblastoma and neuroblastoma survivors are at increased risk for developing components of metabolic syndrome, especially after abdominal irradiation. We emphasize that survivors treated with abdominal irradiation need alternative adiposity measurements for assessment of metabolic syndrome.