Detection and Treatment of Endocrine Abnormalities in Childhood Cancer Survivors and Hematopoietic Stem Cell Transplant Recipients

This study will determine the prevalence of endocrine-related side effects in children who have been treated for cancer and establish a database and registry organized according to cancer diagnosis, treatments and endocrine side effects. In children, the endocrine system, which includes glands and hormones that help to control metabolism, growth, development and reproduction, is particularly vulnerable to long-term side effects associated with cancer and its treatments. The study will also serve to help train medical fellows, residents and students in identifying and managing endocrine abnormalities in children who have been diagnosed with and treated for cancer. Children between 2 and 24 years of age who have been treated for a childhood cancer and have been disease-free for at least 1 year may be eligible for this study. All participants undergo the following procedures: * Review of cancer treatment record * Review of medical and family history * Blood draw for DNA studies * Physical examination and body measurements (height, weight, waist, body proportions) * Completion of child health questionnaires * Individualized screening and counseling program * Review of the following endocrine systems: growth, pituitary and hypothalamic function, thyroid function, ovary and testicular function, bone health, risk of obesity and diabetes The following additional studies may be done, as clinically indicated: * Magnetic resonance imaging (MRI) of the brain * Thyroid, testicular or ovarian ultrasound * DEXA scan to measure bone density * Wrist x-ray to measure bone age * Blood tests * Urine pregnancy test for girls who are old enough to have menstrual periods * Stimulation testing (tests that involve giving medicine by mouth or in the vein and then measuring blood levels of substances afterwards, such as oral glucose tolerance test, arginine-clonidine growth hormone stimulation test, ACTH stimulation test, and gonadotropin-releasing hormone stimulation test) Children with endocrine abnormalities are offered standard treatments.