The rules for predicting remission in patients with Cushing disease after successful endoscopic transnasal adenomectomy

BACKGROUND: The recurrence rate after successful transnasal adenomectomy in Cushings disease (CD) can reach 47%. We have previously shown that patients with ACTH levels less than 7 pg/ml recurred over 3 years 4.5 times less often than patients with higher levels of ACTH, patients with cortisol levels below 123 nmol/l in 3.4 times less than at higher values of this hormone, however, these indicators are dissociated in 41% of cases, so it is not possible use them for prediction separately. AIM: To develop a method for managing patients after successful transnasal adenomectomy depending on prognosis. METHODS: A monocenter retrospective comparative study included 349 patients (52 men, 297 women) with a confirmed diagnosis of CD, who underwent effective endoscopic transsphenoidal adenomectomy in 20072014. Various combinations of postoperative morning levels of ACTH and cortisol were analyzed. RESULTS: Based on the developed forecasting methods and their best characteristics, the following rules were formulated. If postoperative morning ACTH is less than 7 pg/ml and/or postoperative morning cortisol is less than 123 nmol/l, then the patient will remain in remission for 1 year with probability of 99% (95% CI 97%100%) and for 3 years with probability of 86% (95% CI 80%91%). CONCLUSION: The rules for predicting remission for 1 and 3 years for patients after neurosurgical treatment for CD are proposed. These rules are based on combinations of ACTH and cortisol levels.