Predictive Value of Early Postoperative Course of Serum Cortisol After Transsphenoidal Surgery for Cushing's Disease

To identify early available predictors for the long-term outcome of patients after transsphenoidal surgery (TSS) in the management of Cushing's disease.

This single-center, retrospective study included 93 consecutive patients with Cushing's disease (follow-up 12-129 months, mean 48, median 38) who underwent TSS (21 had previous operations elsewhere). Six cases had early re-operation, and the resulting data were evaluated instead of the respective first operation. During the postoperative course, serum cortisol levels were assessed every four hours at least until the next morning. An association of parameters with long-term outcomes was tested using binary logistic regression. Receiver operating characteristic curves were used to determine sensitivity, specificity, positive predictive value, and negative predictive value of different cut-off values of serum cortisol in the postoperative course in the event of recurrence after remission.

Eighty out of 93 patients (86%) showed postoperative remission (after primary treatment, 60 out of 72 patients, 90.3%). Of these, 8 patients (10%) developed recurrence of hypercortisolism. Compared to patients with persisting long-term remission, those with recurrence differed in cortisol levels starting from 4 pm on the day of surgery plus an event of increasing cortisol during the early postoperative course ("peak"). Binary logistic regression showed the association between a peak of serum cortisol in the early postoperative course with an increased probability of recurrence.

Patients with a peak of serum cortisol in the early postoperative course show an increased recurrence rate. A cut-off value of serum cortisol for clear identification of patients with later recurrence could not be determined.