MON-108 - PIONEER-US: An Automated, Prospective, Multicenter Registry of Pituitary Adenomas in the USA

Background: National pituitary adenoma registries enable assessment of clinical outcomes across larger, more diverse cohorts than typically available at single centers. PIONEER-US, the PItuitary adenoma Outcomes aNalysis Evidence-basEd Registry, is a prospective, multicenter registry that uses a standardized, EHR-driven methodology developed to capture longitudinal, high-fidelity data on patients treated at multidisciplinary pituitary centers in the US, enabling rigorous valuation of epidemiology, disease burden, and treatment outcomes. We report baseline characteristics of patients with pituitary adenomas enrolled prior to surgical or medical intervention; pediatric patients were diagnosed within 5 years. Microprolactinomas treated medically are not included.

Methods: Structured data are automatically extracted from the local EHR to site-level REDCap registries using standardized scripts and uniform data dictionaries. After manual validation and de-identification at the local site, data are exported on a scheduled basis to a central REDCap registry, where automated range and logic checks and targeted manual reviews verify data accuracy and completeness. For this analysis, we queried the central registry for demographics, diagnosis, preintervention imaging findings (largest adenoma dimension; any cavernous sinus invasion or Knosp >0; optic chiasm abutment, compression, or displacement), and hypopituitarism and comorbid cardiorespiratory/metabolic disorders identified by ICD-10 code. Results were summarized using counts (n) and percentages (%) for categorical variables, and means with standard deviations (SD) for continuous variables.

Results: Enrollment continues at 6 centers. 355 adults and 14 children were enrolled between May 2023 and March 2026. Mean age in adults was 53 (SD 16) years; 50% were female and 20% Hispanic. NFA was most common (48%), followed by prolactinoma (21%), acromegaly (15%), and Cushing disease (CD, 15%). TSHoma and LH/FSHoma comprised < 1%. Adenoma size averaged 25 (SD 10) mm in those with NFA, 18 (SD 11) mm in acromegaly, 17 (SD 10) in prolactinoma, and 12 (SD 12) in CD. In the pediatric cohort, mean age at diagnosis was 14.5 (SD 2), with 71% female and 36% Hispanic. There were 9 prolactinomas (mean 10 [SD 6] mm]), 3 CD adenomas (mean 18 [SD 5] mm), 1 acromegaly (30 mm) adenoma, and 1 NFA (32 mm). Cavernous sinus invasion was present in 62% of adults and optic chiasm involved in 62%; rates were 29% and 29%, respectively, in the pediatric cohort. Preintervention hypopituitarism was present in 20% of adults and circulatory disorders in 28%; 11% had diabetes/insulin resistance, and 8% sleep apnea/snoring.

Conclusions: The automated prospective, multicenter PIONEER-US registry was developed to enable capture of heterogeneous pituitary adenoma phenotypes, providing a robust platform for studying the US clinical landscape of these rare disorders.

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