Persistent adrenocorticotropin response to desmopressin in the early postoperative period predicts recurrence of Cushing's disease.

CONTEXT:
Patients with Cushing's disease (CD) often show an ACTH and cortisol response to desmopressin (DDAVP).
OBJECTIVE:
We tested whether persistence of a positive response to DDAVP after successful surgery identifies patients at risk of CD recurrence.
DESIGN:
We prospectively included all CD patients who had a positive response to DDAVP before successful surgery from 1995 through 2007.
SETTING:
The study was performed at a university hospital.
PATIENTS:
One hundred seventy-four patients with CD, 148 women and 26 men, mean age 36.1 +/- 0.8 yr, were studied. The median follow-up after surgery was 58 months (interquartile range 22-93 months).
INTERVENTION:
DDAVP test was performed immediately before and after surgery.
MAIN OUTCOME MEASURE:
An ACTH and cortisol increment of at least 30 and 20% above baseline, respectively, were considered as a positive response to DDAVP. The risk of CD recurrence was analyzed according to the postoperative hormonal response to DDAVP.
RESULTS:
Recurrence of CD occurred in 19 patients (10.9%). The recurrence-free survival at 5 yr was 89.8% [95% confidence interval (CI) 84.2-95.4]. Patients with a positive ACTH response had a 5-yr recurrence-free survival of 82.6% (95% CI 70.6-94.6%) as compared with 94.0% (95% CI 88.2-99.8%; P < 0.01) in patients without it. Multivariate analysis showed that persistence of a positive ACTH response to DDAVP was significantly associated with CD recurrence.
CONCLUSION:
Positive ACTH response to DDAVP after surgery is associated with an increased risk of CD recurrence. However, the specificity and predictive value of this finding are low.