Background: Recent population-based studies have demonstrated significant differences in outcome between patients with pancreatic and ileal neuroendocrine tumors. The objective of this study was to examine the clinicopathologic differences between ileal and pancreatic neuroendocrine tumors following resection.
Methods: A retrospective chart review was performed and data on clinicopathologic variables, biochemical markers, and follow-up of patients with resected ileal (INETs) and pancreatic (PNETs) neuroendocrine tumors were collected. The t test or analysis of variance (ANOVA) was used to compare means. Survival analysis was performed using the Kaplan-Meier method.
Results: Between 1998 and 2010, 122 patients with PNETs and INETs were explored (70 PNETs and 52 INETs). Several variables were found to be significantly different between patients in both groups. INETs were more often associated with flushing (44 vs. 14%; P < 0.001) and diarrhea (63 vs. 16%; P < 0.001) and were more often associated with elevation in preoperative serum levels of pancreastatin (88 vs. 42%; P < 0.001), chromogranin A (78 vs. 54%; P = 0.036), and serotonin (90 vs. 43%; P < 0.001). INETs more frequently had vascular invasion on pathology (96 vs. 60%; P < 0.001), and presented more often with nodal and/or distant metastases (77 vs. 37%; P < 0.001). There was no significant difference in overall survival between patients in both groups.
Conclusion: In this series, patients with INETs presented with a more advanced stage of disease compared with PNETs, had higher preoperative levels of 3 markers, and were more often symptomatic. Despite these factors, there was no significant difference in overall survival between patients with these 2 tumor types.