Recurrence of Cushing’s disease (CD) after transsphenoidal surgery (TSS) occurs in about 25% of cases. Twenty percent of patients with immediate postsurgical corticotroph deficiency will present late recurrence.Objective:
The aim of the study was to evaluate a coupled dexamethasone desmopressin test (CDDT) as a predictor of recurrence of CD.Design:
We conducted a prospective bicenter study (Marseille and Grenoble, France).Patients:
We studied 38 patients treated by TSS for CD with a mean follow-up of 60 months.Intervention(s):
We evaluated 24-h urinary free cortisol, ACTH, and cortisol plasmatic levels and performed low-dose dexamethasone suppression test and CDDT 3 to 6 months after surgery and then yearly.Main Outcome Measures:
After CDDT, ACTH ratio (ACTHr) was defined as (PeakACTH − BaseACTH)/BaseACTH. Cortisol ratio (Cortisolr) was defined as (PeakCortisol − BaseCortisol)/BaseCortisol. Basal values were observed after low-dose dexamethasone suppression test. Receiver operator characteristics curve defined ACTHr and Cortisolr giving the best sensitivity and specificity associated with recurrence.Results:
Ten patients presented recurrence. ACTHr and Cortisolr were superior or equal to 0.5 in all patients with recurrence and in three of 28 patients in remission (100% sensitivity, 89% specificity). The test became positive in eight of 10 patients with recurrence 6-60 months before classical markers of hypercortisolism. Six patients with immediate postsurgical corticotroph deficiency presented recurrence. All of them presented CDDT positivity during the 3 yr after surgery, and recurrence 6 to 60 months after CDDT positivity.Conclusions:
CDDT is an early predictor of recurrence of CD and could be of particular interest in the first 3 yr after surgery, by selecting patients at high risk of recurrence despite falsely reassuring classical hormonal markers.