Mifepristone Effects on Tumor Somatostatin Receptor Expression in Two Patients with Cushing's Syndrome due to Ectopic Adrenocorticotropin Secretion

Abstract

We describe two patients with ACTH-producing bronchial carcinoids, in whom a direct down-regulatory effect of glucocorticoid levels on tumoral sst(2) receptor expression is suggested by a remarkable change in octreoscan status after successful mifepristone therapy. Further studies will have to demonstrate whether glucocorticoid lowering or antagonizing therapy may be used to improve the diagnostic accuracy of somatostatin receptor scintigraphy in patients with ectopic ACTH production of unknown primary origin.