Endocrine Abstracts

Background: Transsphenoidal tumour resection (TSS) is the first-line treatment for Cushing’s disease (CD). With an experienced neurosurgeon, immediate remission rates >80% are expected for patients with microadenomas (<10 mm).

Aim: To report initial and long-term remission rates in a specialist centre, and to ascertain factors associated with disease recurrence after TSS.

Methods: Patients with CD (n=101, 28M, 73F) having TSS by one neurosurgeon (RJW) at Cleveland Clinic between 2004 and 2013, with a minimum one-year follow-up. Glucocorticoids were withheld during and immediately after surgery; ACTH and cortisol were closely monitored postoperatively with a standard protocol to determine initial remission. After discontinuing hydrocortisone for surgically-induced adrenal insufficiency, long-term recurrence was defined by 24 h UFC >ULN, and/or late night salivary cortisol >ULN, and/or 8 AM serum cortisol >1.8 mcg/dl after 1 mg overnight dexamethasone.

Results: Median (range) for age and follow up were 46 (15–87) and 4.33 (1–9.8) years, respectively. 74 patients had microadenoma, 27 macroadenoma. Initial remission rates were: microadenoma 89% (66/74), macroadenoma 63% (17/27). Initial non-remission occurred in 18 patients, ten macro- and eight microadenoma. Six of the 83 patients with initial remission have had recurrence of hypercortisolism requiring either repeat TSS or adjunctive therapy. At last follow-up, continuing remission rates are: microadenoma 90%, macroadenoma 74%; 14 (seven macro, seven micro) have persistent hypercortisolism. Macroadenoma (P=0.003) and tumour invasion beyond the pituitary (P<0.001) were associated with failure of initial remission and greater likelihood of late recurrence. Absence of tumour on pre-operative imaging was not associated with failure of initial remission.

Conclusions: Surgery by a dedicated neurosurgeon in a specialised pituitary centre gives excellent initial and long-term results for CD. Presence of adenoma extension beyond the pituitary and immediate post-operative ACTH and cortisol levels are highly predictive of long-term outcome.