Postoperative testing to predict recurrent Cushing disease in children.

CONTEXT: Postoperative testing after transsphenoidal surgery (TSS) for Cushing disease (CD) in children and its usefulness in predicting residual disease or recurrence are not well studied.

OBJECTIVE: The objective of the study was to identify which one of three tests that are routinely performed in our institution after TSS performs better in the identification of noncured patients or predict relapse for CD.

DESIGN: This was a retrospective review of clinical data of 72 children who received surgery for CD (age range 5.8-18.3 yr).

SETTING: The study was conducted at a tertiary care center.

METHODS: After TSS, plasma ACTH and serum cortisol (at 0800 h), urinary free cortisol (UFC) values and an ovine CRH (oCRH) stimulation test were obtained. Patients were followed up for 24-120 months by a formal protocol.

RESULTS: Of 72 children with CD, 66 (94%) achieved sustained remission after TSS. Two children had persistent disease after TSS, whereas four children appeared cured at first but relapsed later. All four had low or undetectable UFCs that were not different from cured patients (P > 0.0.1). Children who remained in remission had significantly lower morning ACTH and cortisol levels after TSS compared with those who relapsed (P < 0.001). During an oCRH stimulation test, ACTH and cortisol values were higher in patients who relapsed vs. those in remission (P <0.001). Lack of histological confirmation of an adenoma, normal serum cortisol or ACTH, a normal response to oCRH, and glucocorticoid replacement for less than 6 months after surgery were associated with relapse.

CONCLUSION: In pediatric patients with CD, low UFCs after TSS are not good predictors of sustained remission; morning ACTH and cortisol values and/or an oCRH test after TSS predicted patients that recurred.