Clinico-radiological Parameters, Biochemical and Molecular Alterations Predicting Remission and Recurrence after Surgical Treatment of Corticotroph Adenomas – Cushing’s Disease

OBJECTIVE: Endonasal endoscopic transsphenoidal surgery (TSS) and resection of pituitary adenomas are considered the gold standard treatment for Cushing disease (CD). Even with various recent advances in management, disease persistence and recurrence are common in these patients. The remission rate in the global population after surgery has been reported to vary widely from 64% to 93%. This study aims to determine the various clinical, biochemical, radiological, and histological factors that correlate with persistence and recurrence in patients with CD. This study also aims to understand the clinicopathological significance of EGFR-MAPK, NF-kappa B, and SHH pathway activation and to study the protein expression of activation markers of these pathways (i.e., c-Fos, c-Jun, GLI-1, pMEK, NR4A1, and p44) in functioning corticotroph pituitary adenomas. METHODS: From January 2009 to September 2022, the clinical data of 167 patients who underwent surgical treatment (n = 174 surgeries) for CD with a median follow-up of 8.1 years (range, 1-13.29 years) were ambispectively analyzed. The preoperative clinical, biochemical, and radiological features, operative findings, postoperative clinical and biochemical data, and histopathological and molecular profiles were retrieved from the electronic medical records. The patients were followed up to assess their remission status. RESULTS: Among the 174 surgeries performed, 140 were primary surgeries, 22 were revision surgeries, 24 surgeries were for pediatric patients, and 12 surgeries were for patients with Nelson syndrome. In the primary surgery cohort, 74.3% were female, and the average age was 28.73 +/- 10.15 years. Of the primary surgery cohort, 75% of the patients experienced remission compared with 47.4% after revision surgery. The remission rate for the pediatric patients was 55.5%. The postoperative day 1 plasma cortisol (P < 0.001; area under the curve, 0.8894; range, 0.8087-0.9701) and adrenocorticotropic hormone (P < 0.001; area under the curve, 0.9; range, 0.7386-1) levels were seen to be strong independent predictors of remission in the primary surgery cohort. The remission rate after endoscopic TSS was greater than that after microscopic TSS in patients undergoing primary surgery (81.08% vs. 57.14%; P = 0.008). The presence of adenoma on histopathological examination (HPE) was also a strong predictor of disease remission (P = 0.020). On stratifying by surgical approach and HPE, microscopically operated patients without histopathological evidence of adenoma had significantly higher odds of nonremission (odds ratio, 38.1; 95% confidence interval, 4.2- 348.3) compared with endoscopically operated patients with adenoma found on HPE. A lower immunoreactivity score for NR4A1 was found to correlate with higher remission rates (P = 0.074). However, none of the molecular markers studied (i.e., c-Fos, c-Jun, GLI-1, pMEK, and p44) showed a significant correlation with the preoperative cortisol values. CONCLUSIONS: The remission rate after primary surgery is higher than that after revision surgery and is lower for pediatric patients than for adults. The postoperative day 1 plasma cortisol and adrenocorticotropic hormone levels are strong independent predictors of remission in the primary surgery cohort. An endoscopic approach with histopathological evidence of adenoma is associated with a higher remission rate; thus, endoscopy should be the approach of choice for these patients with the goal of identification of an adenoma on HPE.