PROGNOSTIC FACTORS FOR SURVIVAL OF MEN1 PATIENTS WITH DUODENOPANCREATIC TUMORS METASTATIC TO THE LIVER: RESULTS FROM THE DMSG.

OBJECTIVE: Duodenopancreatic neuroendocrine tumors (DP-NETs) develop in a majority of patients with multiple endocrine neoplasia type 1 (MEN1) and are the leading cause of death. Overall survival (OS) and prognostic factors for patients with liver metastases from DP-NETs are not known. METHODS: This was a cohort study using the Dutch National MEN1 database, which includes >90% of the Dutch MEN1 population treated between 1990 and 2014. OS was assessed with time to event analysis, and prognostic factors were evaluated. RESULTS: A total of 56% of the MEN1 patients (n = 220) were diagnosed with a DP-NET, of who 34 (15%) developed DP-NET liver metastases. Median age at liver metastases diagnosis was 53 years (range 31-74). Of those patients, 16 patients (47%) had died after a median follow-up of 4 years (range 0.3-12.3). OS at 2, 5, and 10 years were 91%, 65%, and 50%, respectively. A trend towards worse survival was seen in males compared to females (5-year OS 58% versus 75%, P = .07) and also in patients with multiple liver metastases compared to patients with solitary liver metastasis (59 versus 83%, P = .09). CONCLUSION: Despite the fairly indolent course of DP-NET liver metastases in MEN1 patients, half of the population was deceased after 10 years. Sex and tumor load at diagnosis of liver metastases are possible prognostic factors for worse survival. ABBREVIATIONS: DMSG = DutchMEN1 Study Group; D-NET = duodenal neuroendocrine tumor; DP-NET = duodenopancreatic neuroendocrine tumor; HPF = high-power field; Ki67 LI = Ki67 labeling index; MEN1 = multiple endocrine neoplasia type 1; NET = neuroendocrine tumor; OS = overall survival; P-NET = pancreatic neuroendocrine tumor; PPI = proton pump inhibitor; ULN = upper limit of normal; WHO = World Health Organization