Analysis of Prospective Endocrine Surgery Trials in 2025 From the ClinicalTrials.gov National Registry.

INTRODUCTION: Prospective clinical trials are among the highest levels of evidence in research. However, surgical fields have historically trailed medical specialties in trial quantity and methodological rigor. Endocrine surgery follows this pattern, with guidelines largely based on observational evidence and expert consensus. Therefore, we aimed to compare the number and characteristics of active endocrine surgery trials to those of medical endocrinology studies in the 2025 clinical trial pipeline. METHODS: This is a cross-sectional study of ClinicalTrials.gov, a trial registry maintained by the U.S. National Institutes of Health. We identified active phase I-IV endocrine studies (accessed January 1, 2025) using search terms encompassing thyroid, parathyroid, and adrenal diseases. Trials were categorized into endocrine surgery and nonendocrine surgery studies based on study interventions and available data. Endocrine surgery trials were stratified by study intervention and outcomes based on the surgical phase of care. Descriptive statistics were used for the analysis. RESULTS: Of 341 endocrine clinical trials identified, 43 (13%) were endocrine surgery studies. Among endocrine surgery studies, thyroid disease was the predominant focus (N = 28, 65%), with 6 (14%) parathyroid and 7 (16%) adrenal conditions. Two (5%) were dual thyroid-parathyroid trials. Of 28 thyroid trials, 19 (68%) focused on thyroid cancer treatment. Three (50%) parathyroid studies were technique trials, while the remaining three (50%) assessed diagnostic accuracy. Adrenal trials were primarily diagnostic (71%) and centered around preoperative detection of primary aldosteronism. CONCLUSIONS: Endocrine surgery trials remain underrepresented and are heavily concentrated in thyroid cancer. Parathyroid and adrenal diseases are comparatively understudied, highlighting opportunities for a broader prospective investigation.