IS THERE A ROLE FOR SOMATOSTATIN AND ITS ANALOGS IN CUSHINGS-SYNDROME

The effects of somatostatin and its analogs have been studied in diffe rent subclasses of patients with Cushing's syndrome (due to Cushing's disease, ectopic corticotropin [ACTH]- and/or corticotropin-releasing hormone [CRH]-secreting tumors, or ACTH-independent Cushing's syndrome ) and in patients with Nelson's syndrome. In most patients with untrea ted Cushing's disease, octreotide does not suppress ACTH release, a fi nding that is supported by in vitro studies. However, octreotide or so matostatin inhibits pathological ACTH secretion in Nelson's syndrome. Short-term octreotide treatment has caused a significant initial respo nse (decreased serum cortisol, ACTH, and cortisoluria) in 24 of 38 (64 %) patients with ectopic ACTH/CRH Cushing's syndrome, and long-term tr eatment caused a persistent response in 10 of 14 (71%) cases. Pentetre otide scintigraphy may help to identify those patients with ectopic AC TH/CRH tumors who will have an initial response to octreotide, and is useful for locating ectopic ACTH/CRH-secreting tumors and their metast ases. To date, octreotide has been shown to temporarily suppress gastr ic inhibitory peptide (GIP)-induced cortisol secretion in GIP-dependen t (ACTH-independent) Cushing's syndrome, but has not shown any therape utic benefit in other forms of ACTH-independent Cushing's syndrome. Co pyright (C) 1996 by W.B. Saunders Company