Long-Term Endocrine Outcomes Following Endoscopic Endonasal Transsphenoidal Surgery for Acromegaly and Associated...

Long-term remission rates from endoscopic transsphenoidal surgery for acromegaly and their relationship to prognostic indicators of disease aggressiveness are not well documented.

To investigate long-term remission rates in patients with acromegaly after endoscopic transsphenoidal surgery, and correlate this with molecular and radiographic markers of disease aggressiveness.

We identified all patients undergoing endoscopic transsphenoidal surgery for acromegaly from 2005 to 2013 at Cedars-Sinai Pituitary Center. Hormonal remission was established by normal insulin-like growth factor (IGF)-1, basal serum growth hormone <2.5 ng/mL, and growth hormone suppression to <1 ng/mL following oral glucose tolerance test. Oral glucose tolerance test was performed at 3 months after surgery, and then as indicated. IGF-1 was measured at 3 months and then at least annually. We evaluated tumor granularity, nuclear expression of p21, Ki67 index, and extent of cavernous sinus invasion, and correlated these with remission status.

Fifty-eight patients that underwent surgery had follow-up from 38 to 98 months (mean 64 ± 32.2 months). There were 21 microadenomas and 37 macroadenomas. Three months after surgery 40 of 58 patients (69%) were in biochemical remission. Four additional patients were in remission at 6 months after surgery, and 1 patient had recurrence within the first year after surgery. At last follow-up, 43 of 44 (74.1%) of patients remained in remission. Cavernous sinus invasion by tumor predicted failure to achieve remission.

Prognostic markers of disease aggressiveness other than cavernous sinus invasion did not correlate with surgical outcome. Long-term remission after surgery alone was achieved in 74% of patients, indicating long-term efficacy of endoscopic surgery.