Gross total resection in low-grade and pretreated high-grade invasive growth hormone pituitary adenomas promises favorable outcomes.

INTRODUCTION

Growth hormone (GH)-secreting pituitary tumors cause serious systemic comorbidities, necessitating the achievement of gross total resection (GTR) and biochemical remission. This study aims to identify predictors of resection status and biochemical remission.

METHODS

We retrospectively reviewed the records of 54 GH adenoma patients receiving endoscopic endonasal transsphenoidal approach (EETSA). Medical records and magnetic resonance imaging were reviewed for tumor size, volume, resection status, invasion status, and Knosp and Hardy-Wilson grades. We also classified invasion status into high- and low-grade groups. Biochemical remission was defined as an insulin-like growth factor 1 value within sex- and age-adjusted reference or a random GH level < 1.0 ng/mL.

RESULTS

The degrees of horizontal and vertical invasion based on preoperative Knosp and Hardy-Wilson grade were highly associated with intraoperative resection status (p = 0.0054, 0.0043 and 0.013 respectively). We also found more significant differences between resection status and higher-grade invasion (p = 0.0018, 0.006 and 0.0018, respectively). Hardy-Wilson grades and resection status were significantly associated with biochemical remission (p = 0.0484, 0.0252, and 0.0007, respectively). Although we observed no difference between outcomes with respect to micro- vs. macroadenoma, tumor size and volume were significantly associated with outcomes (p = 0.017, 0.0032, respectively). More significant differences were observed between biochemical remission and higher-grade Hardy-Wilson invasion grade (p = 0.0053 and 0.0075). Multivariate analysis showed that higher-grade Hardy-Wilson invasion correlated with resection status (p = 0.0481 and 0.0125); only resection status was associated with biochemical remission (p = 0.0101).

CONCLUSIONS

EETSA remains the best treatment option for GH adenomas. Biochemical remission was highly associated with invasion status and the possibility of achieving GTR. Aggressive resection for low-grade and pretreated high-grade tumors promises favorable outcomes.