Long-term control of acromegaly after pituitary surgery in South-Eastern Norway

Purpose Sustained cure of acromegaly can only be achieved by surgery. Most growth hormone ( GH) secreting pituitary adenomas are macroadenomas (>= 10 mm) at diagnosis, with reported surgical cure rates of approximately 50%. Long-term data on disease control rates after surgery are limited. Our aim was to estimate short- and long-term rates of biochemical control after pituitary surgery in acromegaly and identify predictive factors. Methods Patients operated for GH-secreting pituitary adenomas between 2005-2020 were included from the local pituitary registry (n = 178). Disease activity and treatment data were recorded at one-year (short-term) and five-year (long-term) postoperative follow-up. Biochemical control was defined as insulin-like growth factor 1 (IGF- 1) <= 1.2 x upper limit of normal value. Multivariate regression models were used to identify factors potentially predicting biochemical control. Results A total of 178 patients with acromegaly (median age at diagnosis 49 (IQR: 38-59) years, 46% women) were operated for a pituitary adenoma. Biochemical control was achieved by surgery in 53% at short-term and 41% at long-term follow-up, without additional treatment for acromegaly. Biochemical control rates by surgery were of same magnitude in paired samples (45% vs. 41%, p = 0.213) for short- and long-term follow- up, respectively. At short-term, 62% of patients with microadenomas and 51% with macroadenomas, achieved biochemical control. At long-term, the biochemical control rate was 58% for microadenomas and 37% for macroadenomas (p = 0.058). With adjunctive treatment, 82% achieved biochemical control at long-term. Baseline IGF-1 levels significantly predicted biochemical control by surgery at short-term (OR: 0.98 (95% CI: 0.96-0.99), p = 0.011), but not at long-term (OR: 0.76 ( 95% CI: 0.57-1.00), p = 0.053). Conclusion In unselected patients with acromegaly, the long-term biochemical control rate remains modest. Our findings indicate a need to identify patients at an earlier stage and improve therapeutic methods and surgical outcomes.

Automated summary

Surgery is necessary for sustained cure of acromegaly. This study aims to estimate the short- and long-term rates of biochemical control after pituitary surgery in acromegaly and identify predictive factors. The findings indicate that the long-term biochemical control rate remains modest in unselected patients with acromegaly.