Role of Immediate Postoperative Prolactin Measurement in Female Prolactinoma Patients: Predicting Long-Term Remission After Complete Tumor Removal.

Background: Transsphenoidal surgery is one of the important treatment options in the management of prolactinomas; however, complete resection of the tumor does not always lead to endocrinological remission. While many studies have investigated preoperative factors associated with surgical outcome, little has been known about the relationship between postoperative factors and long-term surgical outcomes; moreover, there is no consistency in results. The aim of this study was to demonstrate the reliability of immediate postoperative prolactin levels as predictors of long-term outcomes.

Methods: A total of 105 female patients who underwent complete removal of their histologically confirmed prolactinomas were included, and their medical records were retrospectively reviewed. To evaluate the predictability of immediate postoperative prolactin levels for long-term remission, prolactin levels were measured at 2, 6, 12, 18, 24, 48, and 72 h after surgery.

Results: From the 105 included patients, 95 (90.5%) and 10 (9.5%) belonged to the remission and non-remission groups, respectively. A significant difference was observed in the prolactin level measured 6 h after surgery between the remission and non-remission groups, and this difference stayed apparent until 72 h after surgery. We derived a cut-off value for every postoperative time point that showed a significant relationship with disease remission.

Conclusion: Our study suggests that immediate postoperative measurement of prolactin levels is a reliable predictor of long-term remission and can contribute to early identification of patients who require adjuvant treatment after surgery.