A clinicopathological prediction model for remission after transsphenoidal surgery for acromegaly: A retrospective single-center cohort study

Transsphenoidal surgery (TSS) is the primary treatment of choice in acromegaly. Previous research on predicting remission after TSS was mainly based on clinical and radiological data, lacking histopathological evaluation. Our aim is to produce a clinicopathological prediction model for remission after TSS in acromegaly, enabling clinicians to better inform patients on expected treatment outcomes. This single-center study involved retrospective data collection in a large tertiary referral center in The Netherlands. One hundred patients in whom TSS was performed as primary therapy between January 2000 and July 2019 were included. Uni- and multivariate regression models were used to identify predictors of early biochemical remission according to the consensus criteria, long-term remission (defined as an age- and sex-normalized Insuline growth like factor 1and the absence of postoperative treatment (radiation therapy, repeat surgery, or medical therapy) at last follow-up, irrespective of residual tumor on postoperative magnetic resonance imaging ), and long-term remission without residual tumor (defined by the same biochemical and treatment criteria with the additional absence of residual tumor on postoperative magnetic resonance imaging ). In univariate logistic regression, a larger tumor volume, a larger maximum tumor diameter, a higher modified Knosp classification grade, the presence of cavernous sinus invasion, and a higher random growth hormone at diagnosis were significantly associated with lower remission rates. Tumor subtype and proliferation markers were not. In multivariate logistic regression, a simple model with only maximum tumor diameter as an independent variable predicted best for early biochemical remission (OR 0.85, 95% CI 0.78-0.93, P < .001, sensitivity 78.9%, specificity 71.8%), long-term remission (OR 0.79, 95% CI 0.70-0.88, P < .001, sensitivity 79.5%, specificity 73.7%), and long-term remission without residual tumor (OR 0.75, 95% CI 0.66-0.86, P < .001, sensitivity 79.4%, specificity 78.0%). Maximum tumor diameter was the best predictor, while histopathological characteristics were not predictive for remission after TSS in acromegaly in this cohort.