Predictors of long-term remission following trans-sphenoidal surgery in cushing's disease: a systematic review and meta-analysis based on different remission criteria.

Cushing's Disease (CD) is caused by pituitary adenomas, leading to hypercortisolism. This condition burdens patients socioeconomically, with a reduced quality of life and higher mortality. Transsphenoidal surgery (TSS) is the first-line treatment, offering a 78% remission rate. This study aims to identify factors influencing TSS outcomes to find the predictors of remission for improved treatment planning. A systematic search of electronic databases was performed based on the PRISMA guideline. Studies were selected if they reported data on remission and non-remission groups. A comparative meta-analysis was performed based on the variable type. This review included 11,666 patients treated with TSS for CD, with a remission rate of 73.88%. The mean age was 39.1 years, predominantly female (75.21%), with an average follow-up of 53.29 months. Remission rates were higher in patients with positive MRI results (78.47% vs. 66.11%, P < 0.01), microadenomas (79.16% vs. 64.70%, P < 0.01), without cavernous sinus invasion (78.50% vs. 47.54%, P < 0.01), first-time TSS (81.98% vs. 63.80%, P < 0.01), selective adenectomy surgery (81.24% vs. 64.54%, P < 0.01), and positive adenoma pathology (80.37% vs.54.65%, P < 0.01). Patients who achieved long-term remission exhibited significantly lower immediate post-operative serum cortisol, Adrenocorticotrophic Hormone (ACTH), and urinary-free cortisol (UFC) levels. The risk of bias was low across most studies. Our systematic review and meta-analysis demonstrate MRI findings, histopathology, tumor size, post-operative cortisol, ACTH, UFC, tumor invasion, and repetition of surgery as predictors of remission. These factors should be considered in patient selection for TSS to maximize clinical benefits.