Metabolic Syndrome in Childhood Cancer Survivors

RATIONALE: Gathering information about how often metabolic syndrome occurs in young survivors of childhood cancer may help doctors learn more about the disease. PURPOSE: This clinical trial is studying metabolic syndrome in survivors of childhood cancer and in their healthy sisters and brothers.

OBJECTIVES: Primary * Determine the manifestations of metabolic syndrome (MS) in children and adolescents who are survivors of childhood cancer (CCS). * Compare the prevalence of MS in CCS to that of matched healthy siblings of similar age and gender. * Evaluate insulin resistance (as measured by the euglycemic insulin clamp) in CCS and compare to that of healthy siblings of similar age and gender. * Assess the extent to which prevalent obesity and insulin resistance are correlated with other factors that have been identified in the causal pathway associated with the development of the MS that may be altered in the CCS ( e.g., growth-hormone secretion, adipokines \[adiponectin, leptin\], inflammatory mediators \[e.g., interleukin-6\], tumor necrosis factor-α, and C-reactive protein). * Obtain dietary and physical activity assessments of CCS and healthy siblings. Secondary * Explore demographic (age at treatment, sex-specific differences) and treatment-related factors (exposures and dose-related associations with chemotherapeutic agents, radiation, steroids) as potential correlates with insulin resistance, vascular function, and MS in CCS. OUTLINE: Patients undergo a comprehensive medical examination including current and past medical history, family history, review of prescription medications, a physical examination including a body and visceral-fat assessment, and anthropometric (DEXA and bone-age x-ray) and blood pressure measurement. Blood samples are collected to measure growth hormone, adipokines (adiponectin, leptin), cytokines (IL-6 and CRP), fasting insulin, fasting glucose, lipids, oxidized LDL, hypothalami-pituitary-gonadal function (estrogen, FSH, LH, testosterone), and thyroid function (free T4 and TSH). Patients also complete questionnaires on dietary intake and physical activity. Healthy siblings undergo a complete medical examination as patients do, including blood samples collection and questionnaire administration.