Predictors of biochemical remission after transsphenoidal surgery in a large cohort of acromegaly patients.

Purpose: The objective of this study was to characterize the clinical characteristics and factors predictive of biochemical remission in patients with symptomatic acromegaly undergoing transsphenoidal surgery (TSS) at an academic tertiary care center, as defined by the 2022 Acromegaly Consensus Conference guidelines.

Methods: In this single institution, longitudinal, retrospective study, a large cohort of 158 patients with a preoperative diagnosis of acromegaly undergoing surgery at a large, academic, tertiary care center were examined. We excluded 38 patients as IGF-1 testing was performed less than 12 weeks postoperatively.

Results: The majority of tumors were intrasellar macroadenomas (75%), receiving endoscopic surgery (98.3%). Patients who failed remission appeared to have higher raw IGF-1 levels preoperatively (732 ± 313 ng/mL) compared to those who attained remission (278 ± 313 ng/mL), and trended towards higher rates of GH hypersecretion (93.1% vs. 78.4%). Patients failing remission had higher GH levels and IGF-1 levels postoperatively and experienced a lower percentage reduction in raw IGF-1 levels. Multivariable logistic regression demonstrated that the magnitude of preoperative IGF-1 (OR: 1.001, 95% CI: 1.00, 1.003) and the percentage change in IGF-1 (OR: 1.021, 95% CI: 1.01, 1.04) were predictive of remission failure. Radiographic characteristics such as tumor size, suprasellar extension, and location were not necessarily predictive of worse postoperative outcomes.

Conclusions: Lesions which failed to achieve biochemical remission appeared to display distinctive preoperative endocrinological characteristics, with preoperative IGF-1 levels and percentage changes in IGF-1 levels being predictive of biochemical remission status.