Nonfunctioning
neuroendocrine tumors of the pancreas are rare slow-growing
tumors with a more indolent natural history compared with pancreatic
adenocarcinoma. This retrospective report reviews the surgical experience with nonfunctioning
neuroendocrine tumors in an academic referral center. Statistical analysis was performed using Student's t test and Kaplan-Meier method compared with log-rank tests. Thirty-eight patients (24 males and 14 females) underwent surgery for a
neuroendocrine tumor of the pancreas from 1984 through 1999. Twenty-eight patients with a mean age of 59.9 years had nonfunctioning
islet cell tumors and 10 patients with a mean age of 59.1 years had functioning
islet cell tumors (four
gastrinomas, three
glucagonomas, two
insulinomas, and one
vipoma). The nonfunctioning
islet cell tumors were located in the head, neck, or uncinate process in 14 patients (50%), the body in seven (25%), and the tail in seven (25%). Operative procedures for the nonfunctioning
islet cell tumors included nine
pancreaticoduodenectomies, 12 distal
pancreatectomies, three palliative bypasses, and four exploratory
laparotomies without a resection or bypass. Mean survival for the four patients explored and not resected or bypassed was 7 months. Median survival for node-negative patients was 124 months, for node-positive patients 75 months, and for patients with
metastasis to the liver 9 months. Estimated 2-year actuarial survival for the node-negative patients was 77.8 per cent, for node-positive patients 71.4 per cent, and for patients with
metastasis to the liver 36.4 per cent. Six patients (60%) with node-negative disease, three (43%) with node-positive disease, and one (9%) with
metastasis to the liver are alive at a mean follow-up of 41.8 months (range 1-167). Significant differences in median survival and 2-year survival were demonstrated between the node-positive/node-negative patients and those with
metastasis to the liver (P = 0.003). Patients with localized nonmetastatic disease should be considered for pancreatic resection as estimated median survival is 75 months or greater. Hepatic
metastasis is a major predictor of survival.