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Pancreatic Neuroendocrine Tumors (Islet Cell Tumors) Treatment (PDQ®)

Treatment Option Overview

Localized Disease

If technically and medically feasible, primary management of endocrine tumors of the pancreas involves surgical resection with curative intent. Given the rare nature of these tumors, surgical approaches are based upon case series and expert opinion rather than randomized controlled trials.[1] The surgical options listed below are based on retrospective series from single reporting centers.[2-4][Level of evidence: 3iiD or 3iiiD]

Adjuvant therapy has no proven benefit and is, therefore, investigational. There have been no well-controlled trials of adjuvant therapy after complete tumor resection.[5]

Surgical Cytoreduction for Metastases

Surgery plays a role even in the setting of metastatic disease. The symptoms of metastatic functional pancreatic neuroendocrine tumors (NETs) may be ameliorated by the reduction of overall tumor burden through surgical debulking.

The liver is a common site of metastasis from pancreatic NETs. Because of the slow growth rate of many NETs, liver metastases are often resected when technically feasible. Resection of all grossly visible liver metastases can be associated with long-term survival and, in the case of symptomatic hormonally functional tumors, symptom relief.[6] Most symptoms from functional tumors respond to this form of surgical debulking. How much of the favorable survival rates is attributable to patient selection factors is not known (e.g., underlying patient condition, extent of metastases, slow doubling time, and so forth).

A variety of alternative approaches to the management of liver metastases have been reported, including gel-foam embolization or transarterial chemoembolization,[7] radioembolization with radioactive microspheres,[8-10] radiofrequency ablation, cryoablation, and percutaneous alcohol ablation. These alternative approaches have been reviewed.[11]

Results from surgical resection series appear to be more favorable than with these techniques, and surgery is considered to be the standard approach to resectable liver metastases. However, there are no high-quality studies comparing the various approaches. A systematic review of evidence comparing liver resection versus other treatments for patients with resectable liver neuroendocrine metastases found no randomized trials, or even quasi-experimental, cohort, or case-control studies in which the patient population given the alternative therapies was similar enough to the surgery group to draw reliable conclusions.[12] The evidence for resection of all grossly visible liver metastases derives solely from case series.[Level of evidence: 3iiD or 3iiiD]

In most cases, liver metastases are not completely resectable. Cytoreductive surgery, with or without radiofrequency ablation or cryoablation, has been used to palliate symptoms. A systematic review found no randomized or quasi-randomized trials comparing cytoreductive surgery to other palliative approaches such as chemotherapy or tumor product inhibitors.[13] The evidence for surgical cytoreduction of unresectable liver metastases is restricted to case series [Level of evidence: 3iiD or 3iiiD], and interpretation of outcomes may be strongly affected by patient selection factors.

Systemic Therapy for Advanced and Metastatic Disease

Somatostatin analogs may be effective in reducing the symptoms of functional tumors.[14]

Chemotherapy using drugs such as the following, either alone or in combination, has been shown to have antitumor effects, but evidence is weak or conflicting regarding the impact of chemotherapy on overall survival:[15-17]

  • Streptozocin.
  • Doxorubicin.
  • 5-fluorouracil.
  • Chlorozotocin.
  • Dacarbazine.
  • Temozolomide.

More recently, a variety of systemic agents have shown biologic or palliative activity, including:[5,18]

  • Tyrosine kinase inhibitors (e.g., sunitinib).
  • Temozolomide.
  • Vascular endothelial growth factor pathway inhibitors.
  • Mammalian target of rapamycin inhibitors (e.g., everolimus).

Nearly all of the evidence of activity derives from case series.[Level of evidence 3iiiDiv] However, there are ongoing placebo-controlled randomized trials of everolimus [19] and sunitinib [20] that have been reported in abstract form showing an increase in progression-free survival in each case.[Level of evidence 1iDiii]

Favorable responses have been reported in patients with advanced progressive pancreatic NETs after treatment with several radiolabeled somatostatin analogs in which the analogs octreotide, octreotate, lanreotide, or edotreotide are stably attached to the radionuclides 111Indium, 90Ytrium, or 177Lutrium.[21-23] The relative efficacy of these various compounds is unknown. Study designs have been limited to case series with tumor response, biochemical response, or symptom control as the measure of efficacy.[Level of evidence 3iiiDiv]

As noted in each of the clinical situations, there is a paucity or absence of high-level evidence, and a need for randomized controlled trials.[5]

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with islet cell carcinoma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.


  1. Davies K, Conlon KC: Neuroendocrine tumors of the pancreas. Curr Gastroenterol Rep 11 (2): 119-27, 2009. [PUBMED Abstract]
  2. Phan GQ, Yeo CJ, Hruban RH, et al.: Surgical experience with pancreatic and peripancreatic neuroendocrine tumors: Review of 125 patients. J Gastrointest Surg 2 (5): 473-82, 1998 Sep-Oct. [PUBMED Abstract]
  3. Kazanjian KK, Reber HA, Hines OJ: Resection of pancreatic neuroendocrine tumors: results of 70 cases. Arch Surg 141 (8): 765-9; discussion 769-70, 2006. [PUBMED Abstract]
  4. Hochwald SN, Zee S, Conlon KC, et al.: Prognostic factors in pancreatic endocrine neoplasms: an analysis of 136 cases with a proposal for low-grade and intermediate-grade groups. J Clin Oncol 20 (11): 2633-42, 2002. [PUBMED Abstract]
  5. Kulke MH, Siu LL, Tepper JE, et al.: Future directions in the treatment of neuroendocrine tumors: consensus report of the National Cancer Institute Neuroendocrine Tumor clinical trials planning meeting. J Clin Oncol 29 (7): 934-43, 2011. [PUBMED Abstract]
  6. Sarmiento JM, Que FG: Hepatic surgery for metastases from neuroendocrine tumors. Surg Oncol Clin N Am 12 (1): 231-42, 2003. [PUBMED Abstract]
  7. Gupta S, Johnson MM, Murthy R, et al.: Hepatic arterial embolization and chemoembolization for the treatment of patients with metastatic neuroendocrine tumors: variables affecting response rates and survival. Cancer 104 (8): 1590-602, 2005. [PUBMED Abstract]
  8. Nguyen C, Faraggi M, Giraudet AL, et al.: Long-term efficacy of radionuclide therapy in patients with disseminated neuroendocrine tumors uncontrolled by conventional therapy. J Nucl Med 45 (10): 1660-8, 2004. [PUBMED Abstract]
  9. Kennedy AS, Dezarn WA, McNeillie P, et al.: Radioembolization for unresectable neuroendocrine hepatic metastases using resin 90Y-microspheres: early results in 148 patients. Am J Clin Oncol 31 (3): 271-9, 2008. [PUBMED Abstract]
  10. King J, Quinn R, Glenn DM, et al.: Radioembolization with selective internal radiation microspheres for neuroendocrine liver metastases. Cancer 113 (5): 921-9, 2008. [PUBMED Abstract]
  11. Siperstein AE, Berber E: Cryoablation, percutaneous alcohol injection, and radiofrequency ablation for treatment of neuroendocrine liver metastases. World J Surg 25 (6): 693-6, 2001. [PUBMED Abstract]
  12. Gurusamy KS, Ramamoorthy R, Sharma D, et al.: Liver resection versus other treatments for neuroendocrine tumours in patients with resectable liver metastases. Cochrane Database Syst Rev (2): CD007060, 2009. [PUBMED Abstract]
  13. Gurusamy KS, Pamecha V, Sharma D, et al.: Palliative cytoreductive surgery versus other palliative treatments in patients with unresectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours. Cochrane Database Syst Rev (1): CD007118, 2009. [PUBMED Abstract]
  14. di Bartolomeo M, Bajetta E, Buzzoni R, et al.: Clinical efficacy of octreotide in the treatment of metastatic neuroendocrine tumors. A study by the Italian Trials in Medical Oncology Group. Cancer 77 (2): 402-8, 1996. [PUBMED Abstract]
  15. Moertel CG, Lefkopoulo M, Lipsitz S, et al.: Streptozocin-doxorubicin, streptozocin-fluorouracil or chlorozotocin in the treatment of advanced islet-cell carcinoma. N Engl J Med 326 (8): 519-23, 1992. [PUBMED Abstract]
  16. Kouvaraki MA, Ajani JA, Hoff P, et al.: Fluorouracil, doxorubicin, and streptozocin in the treatment of patients with locally advanced and metastatic pancreatic endocrine carcinomas. J Clin Oncol 22 (23): 4762-71, 2004. [PUBMED Abstract]
  17. Kulke MH, Hornick JL, Frauenhoffer C, et al.: O6-methylguanine DNA methyltransferase deficiency and response to temozolomide-based therapy in patients with neuroendocrine tumors. Clin Cancer Res 15 (1): 338-45, 2009. [PUBMED Abstract]
  18. Yao JC, Lombard-Bohas C, Baudin E, et al.: Daily oral everolimus activity in patients with metastatic pancreatic neuroendocrine tumors after failure of cytotoxic chemotherapy: a phase II trial. J Clin Oncol 28 (1): 69-76, 2010. [PUBMED Abstract]
  19. Yao JC, Shah MH, Ito T, et al.: A randomized, double-blind, placebo-controlled multicenter phase III trial of everolimus in patients with advanced pancreatic neuroendocrine tumors (PNET) (RADIANT-3). [Abstract] Ann Oncol 21 (Suppl 8): A-LBA9, viii4-5, 2010.
  20. Raymond E, Niccoli-Sire P, Bang Y: Updated results of the phase III trial of sunitinib (SU) versus placebo (PBO) for treatment of advanced pancreatic neuroendocrine tumors (NET). [Abstract] American Society of Clinical Oncology 2010 Gastrointestinal Cancers Symposium, 22–24 January 2010, Orlando, Florida. A-127, 2010.
  21. Teunissen JJ, Kwekkeboom DJ, de Jong M, et al.: Endocrine tumours of the gastrointestinal tract. Peptide receptor radionuclide therapy. Best Pract Res Clin Gastroenterol 19 (4): 595-616, 2005. [PUBMED Abstract]
  22. Kwekkeboom DJ, de Herder WW, Kam BL, et al.: Treatment with the radiolabeled somatostatin analog [177 Lu-DOTA 0,Tyr3]octreotate: toxicity, efficacy, and survival. J Clin Oncol 26 (13): 2124-30, 2008. [PUBMED Abstract]
  23. Bushnell DL Jr, O'Dorisio TM, O'Dorisio MS, et al.: 90Y-edotreotide for metastatic carcinoid refractory to octreotide. J Clin Oncol 28 (10): 1652-9, 2010. [PUBMED Abstract]
  • Updated: March 7, 2014