A Report from Xth International Pituitary Congress

By Dr. Ed Laws

The Pituitary Congress, a biannual meeting focusing on all aspects of the pituitary gland, was held in Chicago, June 5-7, 2007. The meeting was very successful. There was an excellent turnout, and the topics and organization were of great interest to most of the endocrinologists and neurosurgeons who attended. While this meeting contained very useful information on all aspects of the pituitary gland, those specific to Cushing's included a quite interesting 'Meet the Professors' session entitled 'The Pitfalls in the Diagnosis and Treatment of Cushing's Syndrome,' presented by Drs. X. Bertagna from France and G. Arnaldi from Italy.

One of the symposia had to do with neuroendocrine aspects of obesity and appetite and was primarily focused on the action of Ghrelin. There was, however, a presentation from Sharon Wardlaw on the melanocortin system and its importance in the regulation of energy balance and neuroendocrine function. This is the same class of hormones that are elevated (over-expressed) in patients with Cushing's disease and surely play a role in the typical obesity associated with that condition.

On the second day, the initial plenary lecture was on pituitary cell to cell communication, by Dr. E. Artz of Argentina. In this lecture, the importance of the compound BMP-4 in altering the activity of ACTH-producing cells was emphasized. In addition, there was a discussion of the effect of retinoic acid on inhibiting the growth of ACTH-producing cells. In animal studies this proved to be effective at a dose of 10 mg/kg.

Of importance to patients with Cushing's disease was the excellent lecture given by Richard N. Clayton of the United Kingdom on the assessment of the HPA axis in patients with pituitary disease. They do things a little differently in the U.K., but the basic principles of making the diagnosis and confirming it are essentially the same. Dr. Paul Stewart, also of the U.K., discussed the nuances of glucocorticoid replacement therapy, with no striking new information of practical importance for patients with Cushing's disease.

Among the 'hot topics' was a paper on the molecular mechanisms of glucocorticoid resistance in Cushing's disease. This was from an outstanding European group, and they looked at the molecular mechanisms behind the lack of feedback by circulating glucocorticoid on ACTH-producing cells in Cushing's disease and narrowed this down to a mechanism that involved the aberrant expression of Brg1 and HDAC2 genes, which are involved in the repression of POMC. They are decreased (under-expressed) in patients with Cushing's disease, explaining the mechanism of resistance.

There was a symposium on new aspects of regulation of the HPA axis, with discussions of the influence of mineralocorticoid antagonists, dopamine, and somatostatin on the control of this important axis. There were also a series of abstracts presented as oral presentations and posters related to Cushing's disease. One was on the effect of short-term high-dose Cabergoline on the disease, and it was noted that this drug blunted cortisol secretion in a small subset of patients. Its extensive use will be limited by its cardiac toxicity. The group at the University of Virginia presented their early outcomes of endoscopic transsphenoidal pituitary surgery for hormonally-active pituitary tumors, including good results in patients with Cushing's disease. There was an abstract on silent corticotroph adenomas, emphasizing their aggressiveness. The Chicago group led by Ivan Ciric presented their 40-year experience in 132 patients operated upon for Cushing's disease.

The initial plenary lecture was by John Marshall of the University of Virginia on the complex mechanisms involved in the control of the onset of puberty. Another symposium on the neuroendocrinology of aging, looking at endocrine and gonadal aspects of aging and emphasizing the fact that obesity significantly contributes to numerous problems as we get older. There was also a symposium on growth hormone and prolactin signaling, which was mainly a molecular biology review. A workshop focused on the approach to patients with pituitary insufficiency, and this included problems in patients with traumatic brain injury and non-functioning pituitary tumors.

The final symposium was on the roles for autocrine and paracrine hormone action, primarily focusing on growth hormone and prolactin. The Presidential Address was related to gonadotropic insufficiency and was given by Dr. John Wass of Oxford.

In summary, this was an outstanding meeting, with a significant focus on Cushing's disease and ACTH abnormalities and regulation, along with the various tumors associated with these problems.

Editor's Note: Dr. Ed Laws is currently Professor of Neurosurgery at Stanford University, Stanford, CA. Dr. Laws has been involved with pituitary surgery for 30 years and has performed over 4900 pituitary operations.

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