Endocrine Abstracts

Cushing’s disease (CD) may recur despite early remission following transsphenoidal surgery (TSS). We evaluated whether early post-operative serum cortisol (sF) levels on post-operative days 3, 4, 5 predict recurrence.

Methods: Patients with CD treated at NIH completed a questionnaire regarding remission status, treatment, and recent biochemistry. We analyzed patients with adenomectomy or hemihypophysectomy at initial TSS, with ACTH-staining tumor and at least one year follow-up. Pituitary irradiation was an exclusion criterion.

Results: Follow-up data was available on 322 patients (age at TSS 36.1±0.8 yrs, 80% female, 83% Caucasian). 87.9% of patients had apparent long-term remission (4.8±0.5 yrs). sF on post-operative days 3, 4 and 5 was <55 nmol/l in 77.4%, 76.2 and 72.0% and was <138 nmol/l in 93.0%, 91.9% and 89.6% respectively. 277 of 319 patients (86.8%) achieved at least one sF <55 nmol/l. Of 277 patients with at least one sF <55 nmol/l, 250 (90%) achieved long-term remission vs. 27 (10%) who recurred. Conversely, 73.8% (31/42) of patients with higher sF had long-term remission while 26.2% (11/42) recurred. The predictive value for long-term remission of a sF <55 nmol/l was 90% (250/277; 95% CI 86–94%) and the predictive value for recurrence of higher sF was 26% (11/42; 95% CI 14–42%). No sF value excluded all patients with recurrence.

Conclusion: An early post-operative sF < 55 nmol/l has high predictive value for long-term remission from CD. Immediate re-operation is not required for all patients with higher values, as most achieve long-term remission.