Endocrine Abstracts

Purpose: Transsphenoidal endoscopic surgery (TSS) is the first-line treatment for Cushing’s disease (CD). Persistence and recurrence of hypercortisolism after TSS considered important problem. In this case search for CD remission predictors is actual.

Aim: To study the role of preoperative oral high-dose dexamethasone suppression test (HDDST) in the prognosis of CD remission after TSS.

Materials and methods: 60 patients with Cushing’s disease (nine men, 51 women, mean age 41 years (15–73) who had underwent TSS were included. HDDST was performed in all cases before the TSS. Postoperative examination was done one and two years after surgery. Remission criteria were: secondary adrenal insufficiency (the need for glucocorticoid replacement) or combination of normal midnight serum cortisol level, normal 24 h urine free cortisol (UFC) excretion and serum cortisol suppression less than 50 nmol/l in 1-mg dexamethasone test. The optimal threshold value of serum cortisol suppression in the HDDST for prediction of CD remission after TSS was calculated by ROC-analysis.

Results: One year after surgery CD remission was confirmed in 39 patients, whereas in 21 patients hypercortisolism persisted, after two years – in 36 and 24 patients, respectively. The optimal threshold value of serum cortisol suppression in the HDDST for prediction of CD remission in one year after TSS was 72%. Test’s sensitivity and specificity were 82% and 84%, respectively. The probability of wrong prediction was 17% (P=0.0001).Two years after TS optimal threshold value of serum cortisol suppression remained 72%, with sensitivity and specificity 86% and 80%,the probability of wrong prediction was 16% (P=0.001).

Conclusion: According to our data serum cortisol suppression more than 72% in HDDST may be used as a prognostic criterion for CD remission after TSS.