Morning adrenocorticotropic hormone and cortisol values or an ovine corticotropin-releasing hormone test were better predictors of recurrence of Cushing’s disease in children following transsphenoidal surgery than low urinary free cortisol values, according to new data.
Researchers at the National Institutes of Health set out to identify which of three routine tests work best at identifying patients with Cushing’s disease who are not cured or for the prediction of relapse of the disease.
The study included 72 children aged 6 to 18 years who underwent transsphenoidal surgery. Following surgery, the researchers obtained plasma adrenocorticotropic hormone and serum cortisol, urinary free cortisol and an ovine corticotropin-releasing hormone stimulation test. Children were followed for two to 10 years.
Ninety-four percent of children with Cushing’s disease achieved sustained remission after transsphenoidal surgery. However, two children had persistent disease following surgery and four children appeared cured, but relapsed later — all four children had low or undetectable urinary free cortisol values that were the same as children with cured disease (P>.01).
When compared with children who relapsed, children who remained in remission had significantly lower morning adrenocorticotropic hormone and cortisol levels after transsphenoidal surgery (P<.001).
A subnormal adrenocorticotropic hormone level of <10.8 pg/ml was the best cutoff value for differentiating between remission and relapse, according to the researchers.
Fifty-seven percent of children who had a normal response to ovine corticotropin-releasing hormone experienced recurrence or disease relapse during the early postoperative period; no delayed relapse was observed among children who did not respond to administration following surgery.
Relapse was also associated with a lack of histological confirmation of an adenoma and glucocorticoid replacement for less than six months after surgery.