Genotype-phenotype Pancreatic Neuroendocrine Tumor Relationship in Multiple Endocrine Neoplasia Type 1 Patients: A 23-year Experience at a Single Institution

Background: The aim of this study was to investigate the genotype-phenotype relationship of pancreatic neuroendocrine tumors in patients with multiple endocrine neoplasia type 1 treated at our institution.

Methods: We conducted a retrospective chart review of all patients with multiple endocrine neoplasia type 1 treated at our center from January 1993 to December 2015. Presence of a pancreatic neuroendocrine tumor was determined based on imaging performed at any time from presentation to conclusion of follow-up.

Results: We reviewed 188 patients. The most common site of multiple endocrine neoplasia type 1 mutation was in exon 2 (34/188; 18%). Of 188 patients, 125 had a pancreatic neuroendocrine tumor (61%). Among all patients, 30 of 34 (88%) with an exon 2 mutation had a pancreatic neuroendocrine tumor compared with 95 of 154 (62%) with a mutation in exons 3-10 (P = .002). In the age group of 20 to 40 years, 8 of 9 patients with an exon 2 mutation had a pancreatic neuroendocrine tumor, compared with 24 of 52 patients (46%) with a mutation in exons 3-10 (P = .028). Patients with an exon 2 mutation had a greater frequency of pancreatic neuroendocrine tumor distant metastasis (53% vs 23%, P = .049).

Conclusion: Young patients with multiple endocrine neoplasia type 1 and an exon 2 mutation appear to have a 2-fold greater risk for developing a pancreatic neuroendocrine tumor, and patients with an exon 2 mutation may be at greater risk for developing distant metastasis. Consideration should be given to more intensive screening and more liberal application of primary operative intervention in this potentially high-risk group.