[Short-term and long-term remission after endoscopic transnasal adenomectomy in patients with acromegaly].

Background: Neurosurgery is the most effective treatment for acromegaly. As most of the patients present with macroadenomas, surgical treatment is not always successful, even with the expert level of a neurosurgeon. Assessment of the postoperative remission rates in acromegaly preoperative predictors of treatment efficacy is an urgent task of modern research.

Aim: To assess the short-term and long-term remission of acromegaly after endoscopic transnasal adenomectomy in a tertiary medical center and assess preoperative predictors of the treatment effectiveness.

Materials and methods: A single-center, prospective, uncontrolled study was conducted. We included patients with active acromegaly who did not receive medical therapy with somatostatin analogues and were referred for endoscopic transsphenoidal adenomectomy. Plasma miRNA expression was assessed by quantitative reverse transcription PCR. Postoperative samples of adenomas were sent for study, with the determination of the immunohistochemical staining for somatostatin receptors 2 and 5 subtypes and morphology was performed on postoperative adenoma samples.

Results: The study included 44 patients: 32.8% men, median age 47.0 [34.0; 55.0], IGF-1 744.75 ng/ml [548.83;889.85], growth hormone 9.5 ng/ml [4.94; 17.07]. Tumor volume 832 mm3 [419.25; 2532.38]. Early postoperative remission was achieved in 35 patients (79.5%). Patients who achieved short-term remission had higher IGF-1 and basal growth hormone levels. Median follow-up was 19.0 months [12.5;29.0]. Long-term remission was achieved in 61.4% (27 patients), no remission in 9 (20.5%), recurrency in 2 patients (4.5%), 6 patients were to follow-up (13.6%). In patients with long-term remission, we observed lower growth hormone and IGF-1 levels. No differences in miRNA expression was observesd. The predictive value of basal GH before surgery for long-term remission was assessed: area under the curve 0.811 (95% CI: 0.649; 0.973). A cut-off value of 15.55 ng/mL corresponded to a sensitivity of 70.0% (34.8%; 93.3%), a specificity of 85.7% (67.3%; 96.0%), an accuracy of 81.6% (65 .7%; 92.3%), PPV 63.6% (39.3%; 82.5%), NPV 88.9% (75.4%; 95.4%).

Conclusion: Rates of short-term and long-term remission after endoscopic transsphenoidal adenomectomy in our cohort is 79,5% и 61,4%, respectively, and is comparable with literature data for expert pituitary centers. Preoperative GH shows potential value in predicting the long-term remission of acromegaly, but further studies in a larger sample are needed to obtain more accurate cut-off values.