Predictors of long-term remission after transsphenoidal surgery in Cushing's disease☆

Abstract There is no consensus on the remission criteria for Cushing's disease or on the definition of disease recurrence after transsphenoidal surgery, and comparison of the different published series is therefore difficult. A long-term recurrence rate of Cushing's disease ranging from 2% to 25% has been reported. Predictors of long-term remission reported include: (1) adenoma-related factors (aggressiveness, size, preoperative identification in MRI), (2) surgery-related factors, mainly neurosurgeon experience, (3) clinical factors, of which dependence on and duration of glucocorticoid treatment are most important, and (4) biochemical factors. Among the latter, low postoperative cortisol levels, less than 2 mcg/dL predict for disease remission. However, even when undetectable plasma cortisol levels are present, long-term recurrence may still occur and lifetime follow-up is required. We report the preliminary results of the first 20 patients with Cushing's disease operated on at our hospital using nadir cortisol levels less than 2 mcg/dL as remission criterion.