Prevalence and Predictors of Remission in Patients with Acromegaly Undergoing Microscopic or Endoscopic Transsphenoidal Surgery: Long-Term Outcomes from a Tertiary Care Centre

Introduction: Transsphenoidal surgery (TSS) is the primary treatment of choice for growth hormone (GH)-secreting pituitary adenomas. However, surgical cure rates vary. We aimed to investigate factors determining remission and the need for adjuvant therapy after TSS in patients with acromegaly managed at a tertiary care centre. Methods: In this retrospective single-centre study, data on patients who underwent TSS at a tertiary care centre were collected from 2010 to 2022. Multivariate regression models were used to identify predictors of endocrine remission according to the 2014 consensus criteria (random GH <1 μg/L and insulin-like growth factor 1 normalised for age) and of the requirement for adjuvant therapy. Results: This study included 169 patients (56% female, mean age 37.8 ± 4.9 years), with a mean time from symptom onset to diagnosis of 4.9 ± 3.9 years. Fifty-three (31.3%) achieved remission with a mean follow-up of 5.2 ± 3.4 years. Adjuvant therapy was required in 78 patients, and redo surgery was performed in eight patients. Baseline GH levels were the only significant predictor of disease activity at the last follow-up. Baseline tumour size ( P = 0.003) and nadir GH levels ( P = 0.02) were the only independent factors associated with endocrine remission and the need for adjuvant therapy. Conclusion: Long-term remission in acromegaly following TSS is achieved in 31.3% of patients. Baseline tumour size and pretreatment nadir GH levels are the primary factors associated with achieving endocrine remission and the need for adjuvant therapy.