BACKGROUND Among patients with multiple endocrine neoplasia type 1 (MEN1), 80% develop duodenopancreatic neuroendocrine tumors (dpNETs), of whom 15%–25% die of metastasis. There is a need to identify biomarkers to predict aggressive disease. MEN1 genotype affords an attractive possibility as a biomarker, as it remains constant during life. Currently, patients are clinically diagnosed with MEN1 by the presence of ≥2 primary endocrine tumors (pituitary, parathyroid, and pancreas) or ≥1 primary endocrine tumor with a positive family history. From 10% to 30% of patients diagnosed clinically with MEN1 have no pathogenic germline MEN1 variants.METHODS This was a retrospective study of 162 index patients or probands with genotype-positive and 47 with genotype-negative MEN1 enrolled from 1977 to 2022.RESULTS Compared with patients with genotype-negative disease, patients with genotype-positive disease were younger at diagnosis and had an increased frequency of recurrent parathyroid tumors, dpNETs, and angiofibromas or collagenomas. We propose a weighted scoring system to diagnose genotype-positive MEN1 based on clinical characteristics. No evidence of MEN1 mosaicism was seen in 30 tumors from 17 patients with genotype-negative MEN1. Patients with germline MEN1 variants in exons 2 and 3 had a reduced risk of distant metastases.CONCLUSION The clinical course of genotype-negative MEN1 is distinct from genotype-positive disease, raising uncertainty about the benefits of lifetime surveillance in patients with genotype-negative disease. MEN1 mosaicism is rare.TRIAL REGISTRATION ClinicalTrials.gov NCT04969926FUNDING Intramural Research Program of National Institute of Diabetes and Digestive and Kidney Diseases, NIH (ZIA DK043006-46)
Charlita C. Worthy, Rana Tora, Chandra N. Uttarkar, James M. Welch, Lynn Bliss, Craig Cochran, Anisha Ninan, Sheila Kumar, Stephen Wank, Sungyoung Auh, Lee S. Weinstein, William F. Simonds, Sunita K. Agarwal, Jenny E. Blau, Smita Jha
Study schematic.