Outcomes after primary tumor resection of metastatic pancreatic neuroendocrine tumors: An analysis of the National Cancer Database

Introduction There is no consensus regarding the role of primary tumor resection for patients with metastatic pancreatic neuroendocrine tumors (panNET). We assessed surgical treatment patterns and evaluated the survival impact of primary tumor resection in patients with metastatic panNET.Methods Patients with synchronous metastatic nonfunctional panNET in the National Cancer Database (2004-2016) were categorized based on whether they underwent primary tumor resection. We used logistic regressions to assess associations with primary tumor resection. We performed survival analyses with Kaplan-Meier survival functions, log-rank test, and Cox proportional hazard regression within a propensity score matched cohort.Results In the overall cohort of 2613 patients, 68% (n = 839) underwent primary tumor resection. The proportion of patients who underwent primary tumor resection decreased over time from 36% (2004) to 16% (2016, p < 0.001). After propensity score matching on age at diagnosis, median income quartile, tumor grade, size, liver metastasis, and hospital type, primary tumor resection was associated with longer median overall survival (OS) (65 vs. 24 months; p < 0.001) and was associated with lower hazard of mortality (HR: 0.39, p < 0.001).Conclusion Primary tumor resection was significantly associated with improved OS, suggesting that, if feasible, surgical resection can be considered for well-selected patients with panNET and synchronous metastasis.