Study of Adrenal Gland Tumors

The adrenal glands are the major source in the body of the steroid hormones. In normal physiology, the pituitary hormone ACTH regulates the secretion of glucocorticoids, while the secretion of mineralocorticoids such as aldosterone is controlled by the renin-angiotensin system. In addition to these two classes of steroids, the adrenal gland secretes lesser amounts of intermediate metabolites as well as dehydroepiandrosterone (DHEA) and its sulfated product (DHEAS) and androstenedione, testosterone, estrogen, and estrone. Dysregulated secretion of any of these hormones can be caused by sporadic adrenocortical adenomas or carcinomas, with the development of specific clinical syndromes depending on the identity of the hormones secreted. In at least a subset of cortisol-producing adrenocortical neoplasms, the presence of ectopic or abnormal receptors has been described, resulting in the regulation of cortisol and/or aldosterone by non-physiologic stimuli. The present study will serve as a mechanism to investigate individuals with steroid hormone-secreting adrenocortical tumors of all types for the purpose of identifying hereditary, congenital, or acquired defects leading not only to hormone oversecretion, but also to tumor formation. One of the first goals of the study was (until very recently) to examine the prevalence of ectopic receptor expression in cortisol- and/or aldosterone- hormone secreting adrenocortical tumors. This led to the understanding of the ontogeny of these tumors and the development of novel therapeutic strategies (e.g., receptor antagonists) to control hormone oversecretion. We currently use this information for the evaluation and treatment of our patients. An important research goal of the study is to identify novel genetic defects leading to tumors of the adrenal gland. This is done through a set of methods, from sequencing of the collected DNA to analysis of the expression of large sets of genes using gene array/gene chip analysis. This information may help to identify patients who would benefit from more aggressive intervention strategies, especially those with potentially malignant tumors. This study also provides the patient cohort necessary for the establishment of a bank of tissues of varying tumors of the adrenal cortex, which may serve in the future as an experimental resource to test new diagnostic and therapeutic methods. Finally, an important and more recent goal of this study is to investigate the effects of excess aldosterone on renal, cardiac, metabolic, and bone systems in patients with primary hyperaldosteronism, an important subgroup of patients with adrenocortical tumors. Patients with hyperaldosetronism have not been studied with the same rigor as patients with hypercortisolism in the past; this study aims at investigating the relative contribution of hyperaldosteronism in the etiopathogenesis of a number of clinical problems in patients with adrenocortical lesions and hypertension.