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Neuroendocrine Tumors

a. Non-Pancreatic Neuroendocrine Tumors

Revised 15 July 2013

Staging Diagram & TNM Classification


General Aspects - Introduction

The neuroendocrine tumours (NETs) include gut carcinoids and tumours of the endocrine pancreas. They are uncommon tumours that arise from the diffuse endocrine system (DES) of the gut, which comprises at least 15 specialized epithelial cells of endodermal origin. Gut DES cells and the neoplasms that arise from them express several antigens that they share with neural elements; hence, the designation neuroendocrine tumours. These are uncommon tumours and make up 0.25% of oncologists’ patient load. As treatment continues to improve, a significant proportion of these patients can expect a good intermediate term prognosis. It is important, therefore, that a management plan be in place. Referral to a BC Cancer Agency centre for guidance is recommended. The first part of this section deals with general aspects of diagnosis and management of NETs, while the second section provides more details of specific tumour types.

Clinical aspects

From a clinical standpoint, NETs can be divided into two groups: functioning and nonfunctioning. Functioning NETs hypersecrete hormones that cause specific syndromes (e.g. carcinoid syndrome) and they are named according to the hypersecreted hormone (insulinoma, gastrinoma, etc). The symptoms caused by the hypersecretion of these hormones often lead to their discovery. Nonfunctioning tumours, which account for about one-third to one-half of NETs, are not associated with a hypersecreted-related clinical syndrome. They come to attention because of their “mass effect” due to tumour bulk. Metastatic disease is usually present at diagnosis. Because they are usually slow growing, NETs are frequently diagnosed late in their course. Those arising in the gut can cause intermittent abdominal discomfort for months or years, often interpreted to be a functional disorder. Later, bowel obstruction occurs secondary to desmoplastic reaction of the mesentery or, less commonly, from the tumour.

Pathology

A correct histological diagnosis is critical and this requires an adequate biopsy. A distinction should be made between a well-differentiated and a poorly differentiated neoplasm as well as between well differentiated benign endocrine neoplasms, neoplasms of uncertain behavior and malignant neoplasms. This distinction can be aided by several features of the tumour: size, invasion of adjacent tissue or wall, invasion beyond the submucosa, angioinvasion, perineural invasion, a solid organoid structure, presence of necrosis, >2 mitoses per high power field, Ki67 index >2%, loss of chromogranin A immunoreactivity or hormone expression.

Tumour markers

  1. Chromogranin A is present in the wall of secretory granules and is co-released with the hormones. Serum chromogranin A is a useful marker for both functioning and nonfunctioning NETs
  2. 5-hydroxyindoleacetic acid (5HIAA) is a metabolic product of serotonin and is excreted in the urine. Measurement of this in a 24-hour urine collection is useful for the diagnosis and follow-up of NETS, especially mid-gut NETs (carcinoid tumours)
  3. Other markers are useful for specific subtypes of NETs (e.g. gastrin for gastrinoma or insulin for insulinoma)

Imaging studies

Radiologic studies and nuclear imaging play an important role in the diagnosis and management of patients with NETs.

  1. Conventional imaging
    Conventional imaging, such as ultrasound and CT scan can be helpful in diagnosis and staging of NETs.
    MRI is not routinely used to evaluate NETs, but it is useful when CT scan or ultrasound gives conflicting or inclusive results. 
    Conventional PET with FDG is not useful for well-differentiated NETs, but it may detect the less well-differentiated tumours.
  2. 111In-penetreotide scintigraphy (OctreoScan)
    Penetreotide is a somatostatin analog which shares the receptor-binding profile of octreotide and it concentrates in tumours containing the somatostatin receptors subtypes 2 and 5. It is highly sensitive for NETs, and both functioning and nonfunctioning tumours can be imaged. Small tumours can be detected by OctreoScan, and it is, therefore, useful as a staging test before surgery. Avidity on OctreoScan can also predict a positive response to octreotide therapy.
  3. MIBG scintigraphy
    MIBG (meta-iodobenzylguanidine) is concentrated in NETs and the occasional tumour will take up MIBG and not octroetide. OctreoScan is, however, considered, the superior diagnostic test.

Principles of management

The principal goal of management is tumour resection for cure. When this is not achievable, the goals of treatment include symptom control, biochemical control (i.e. controlling excess bioactive peptides), objective tumour control and improving patient quality of life. In recent years, the management has become complex with the introduction of a number of new strategies; hence, a multidisciplinary approach is recommended.

Surgery

Surgery is the mainstay of management for localized disease and offers the best chance of cure. Small pancreatic NETs or localized NETs of the gut are amenable to surgical resection even in the presence of regional nodal metastases. Small tumours (<2 cm) can be excised, but more radical surgery is required for larger tumours. Complete surgical resection may be hindered by the large bulk of the tumour or the presence of unresectable regional or distant metastases. Because of the slow growth of NETs in general, cytoreductive therapy should be considered. This includes tumour resection, radiofrequency ablation, and tumour embolization. These measures often improve hormone-related symptoms. A meta-analysis of cytoreductive partial hepatectomy in patients with carcinoid tumour showed a 5-year survival rate of 71% and complete resolution of the carcinoid syndrome in 86% of patients, which lasted 4 to 120 months.

Hepatic artery embolization alone or in combination with intra-arterial chemotherapy (doxorubicin, 5FU or mitomycin C) can reduce clinical symptoms. In 70-90% of patients, there is a biochemical response, and in 30-50% there is significant tumour reduction. Patients with NET of the mid-gut should be considered for palliative resection even in the presence of metastatic disease, since the mesenteric fibrosis that develops can make later resection difficult.

Liver transplantation may be an option for young patients with no extra-hepatic sites of metastases. Recurrence of disease within months or years has, however, been observed in patients who have undergone liver transplantation.

Medical treatment

This site is under construction. If you are concerned about care for a specific patient, please contact the oncologist at your local centre.

Specific Sites

Foregut Neuroendocrine Tumours

The foregut NETs include tumours arising in the stomach, duodenum, pancreas as well as in the lung and thymus.

Stomach Neuroendocrine Tumors

The incidence of stomach NETs is 0.2 per 100,000 population.

Pathology

The majority are well-differentiated and composed of enterochromaffin-like cells (ECL). Rarely, gastrin-producing (G), somatostain-producing (D) or serotonin-producing (EC) cell tumours may occur. Four types are identified:

  • Type 1 is the most common, representing 70-85% of stomach NETs. They are more common in women. Multiple, small benign polyps are present (WHO group 1). They are secondary to hypergastrinemia associated with chronic atrophic gastritis, and ECL-cell hyperplasia is always evident. The prognosis is excellent.
  • Type 2 is rare and is associated with primary hypergastrinemia. This type is part of the Zollinger-Ellison syndrome (ZES) associated with MEN-1. They are multiple benign polyps and only rarely are they malignant. The prognosis is very good with median survival of 84 months.
  • Type 3 accounts for 13-20% of gastric NETs. There is no definite predisposing factor. The tumour appears as a single lesion and belongs to WHO group 2: Ki-67 >2%, >2cm in diameter, infiltrative growth and metastases to regional nodes and liver. A small minority (5%) may produce histamine, causing the “atypical carcinoid syndrome”. The median survival is 28 months.
  • Poorly differentiated tumours with positive staining for synaptophysin occur rarely (<5%). They are highly malignant (WHO group 3). The prognosis is poor with median survival of 7 months.

Clinical presentation

Stomach NETs are usually asymptomatic. They may be found incidentally or in patients with pernicious anemia. Larger tumours can bleed. An atypical carcinoid syndrome can occur with generalized flushing, lacrimation, wheezing and diarrhea.

Special Diagnostic Procedures

  1. Tumour imaging
    Gastroscopy and endoscopic ultrasound (EUS), abdominal ultrasound or abdominal CT scan, and octreotide scintigraphy
  2. Biochemistry
    Chromogranin A and gastrin 
    Parietal cell antibodies
    MEN-1 is excluded by measurement of ionized calcium, PTH and possibly pituitary hormones

Management

  1. Surgery
    This is a potentially curative modality.
    Type 1 and 2 tumours
    Polyps < 1 cm in diameter: Surveillance yearly
    Polyps > 1 cm in diameter: If 1-6 polyps - endoscopic resection and surveillance
    If > 6 polyps, extension to muscularis, repeated recurrences – surgical resection or antrectomy (to reduce gastrin stimulation from antral cells)
    Any evidence of malignant transformation: partial or total gastrectomy
    Type 3 tumours and poorly differentiated tumours
    Partial or total gastrectomy with lymph node dissection (similar to gastric adenocarcinoma)

Systemic Therapy

This site is under construction. If you are concerned about care for a specific patient, please contact the oncologist at your local centre.

Duodenal Neuroendocrine Tumours

Duodenal NETs are rare (<1 per 100,000 population). Patients present with dyspepsia with duodenal ulcer. Anemia may be present. Most are found incidentally. Overall five-year survival is 51%; for localized disease the five-year survival is 66%, for regional disease 28%, and for distant metastases 17%.

Pathology

The majority is well-differentiated and composed of gastrin-producing (G) cells, somatostatin-producing (D) or serotonin-producing (EC) cells.

Special Diagnostic Procedures

  1. Tumour Imaging
    Endoscopy, EUS, CT scan and octreotide scintigraphy
  2. Biochemistry
    Chromogranin A
    Further tests depending on clinical presentation: gastrin, calcitonin, somatostatin, urinary 5HIAA

Management

  1. Surgery
    Surgery is curative for localized disease. Small duodenal tumours may be resected by endoscopy or surgery. Large tumours require pancreaticoduodenal resection or Whipple’s resection. Unresectable tumours may be stented or a surgical by-pass procedure performed.
  2. Systemic

This site is under construction. If you are concerned about care for a specific patient, please contact the oncologist at your local centre.

For gastrin-producing tumours, proton pump inhibitors should be used to control acid-related symptoms.

Pancreatic Neuroendocrine Tumours

See next section for Pancreatic Neuroendocrine Tumours​.

Neuroendocrine Midgut Tumours

Epidemiology

The incidence of endocrine midgut tumours is 0.28-0.8 per 100,000 population. The terminal ileum, close to the ileocecal valve, is the most common site. Both men and women are affected equally and the disease has a peak incidence in the 6th and 7th decade. The cancers are often multicentric, and in 15% of patients there may be a metachronous cancers, such as GI adenocarcinoma or breast cancer. Appendiceal NETs account for 19% of all GI NETs. They are more common in women and occur commonly in the 4th and 5th decade of life.

Clinical Presentation

Nonfunctioning tumours are usually discovered incidentally or during a search for liver metastases of neuroendocrine origin. The main symptom is intermittent abdominal discomfort for months or years, caused by angulation of the small bowel from the desmoplastic reaction of the mesentery. Appendiceal NETs are mostly found during appendectomy. They can cause appenditis by blocking the lumen.

Functioning NETs can give rise ot carcinoid syndrome (flushing, diarrhea, intermittent brochospasm and carcinoid heart disease), which is the present in 4-10% of patients at diagnosis. Abdominal discomfort may also occur. Rarely, a pellagra-like rash is present.

Special Diagnostic Procedures

In addition to the usual diagnostic tests, colonoscopy may identify a primary in the distal ileum or the ileocecal valve region. Small bowel enteroclysis can be useful. Capsule endoscopy is a promising new method to find a primary in the small intestine.

Management

  1. Surgery
    Midgut NETs: Surgery can be curative for NETs confined to the bowel or with regional nodal metastases. In the presence of liver metastases, cytoreductive surgery can be considered if >90% of the tumour can be safely removed. Removal of the primary tumour should be considered even in the presence of metastases to prevent intestinal obstruction or ischemic complications due to fibrotic reaction in the mesentery.

    Selective chemoembolization is a useful option when surgery is not feasible as a cytoreductive procedure. For chemoembolization, doxorubicin is the agent most often used. Local ablative therapy by radiofrequency ablation is indicated in suitable patients with metastatic liver disease.

    Appendiceal NETs: These can be cured by appendectomy if the tumour is located at the tip of the appendix and the tumour diameter is <1cm. A right hemicolectomy is indicated if any of the following feature is present: tumour diameter >1cm; vascular or perineural invasion, location of the tumour at the base of the appendix; histology consistent with goblet cell carcinoid or mixed endocrine-exocrine tumour, tumour between 1 and 2 cm in size with meso-appendiceal involvement and/or positive margins.

Medical management

  1. Octreotide is effective in improving symptoms in 40-80% of patients and is indicated for functioning midgut NETs.
  2. Systemic chemotherapy is not effective in patients with well differentiated NETs. For fast-growing tumours, cisplatin plus etoposide may be effective.
  3. Somatatostatin receptor radionuclide therapy. Patients whose tumours are receptor-positive, as proven by an OctreoScan, are candidates for radionuclide therapy.  Patients being considered for radionuclide therapy should be reviewed at a BCCA GI multidisciplinary conference.

Carcinoid heart disease

About 50% of patients with carcinoid syndrome are at risk of developing carcinoid heart disease, which characteristically affects the right side of the heart and can lead to right-sided heart failure and death. Screening for carcinoid heart disease should be performed on a regular basis in these patients, especially if the urinary 5HIAA is >50mg/24 hours. A baseline echocardiogram should be done at diagnosis of carcinoid syndrome, and then yearly. Those patients with any cardiac changes should be followed by a cardiologist. Patients with valvular heart damage should be referred to a cardiac surgeon for consideration of valve replacement. Because the morbidity and mortality of cardiac surgery in carcinoid patients is high when symptoms of right heart failure are advanced, early intervention is favored. The role of octreotide in suppressing 5HIAA levels to protect against heart damage is controversial, but it seems reasonable to suppress 5HIAA levels as low as possible with adequate doses of octreotide.

Neuroendocrine Tumours of the Hindgut

Hindgut NETs are located distal to the watershed in the transverse colon (middle colic artery).

Epidemiology

Most are in the rectum and the incidence appears to be increasing. They account for 27% of all GI NETs. Colonic NETs are uncommon and make up about 8% of NETs.

Clinical presentation

Rectal NETs: They may cause bleeding per rectum or lower bowel symptoms (tenesmus, rectal discomfort or a change in bowel pattern) or can be found incidentally at endoscopy. Symptoms of carcinoid syndrome are rare.

Colon NETs: They tend to present late with metastatic disease. Patients have symptoms of fatigue, weight loss and abdominal discomfort or pain. The presumptive diagnosis is often colon adenocarcinoma until confirmed by histology.

Special Diagnostic Procedures

  1. Biochemistry
    ​Chromogranin A is likely to be elevated, but 5HIAA is usually normal. Serum acid phosphatase and HCG levels may be elevated.
  2. Endoscopy
    A full colonoscopic assessment is required to rule out a concomitant bowel lesion, such as carcinoma. An endorectal ultrasound is recommended to assess the tumour size depth of invasion and pararectal nodal involvement for rectal carcinoids.

Management

  1. Surgery
    Rectal NETs can be cured by surgery if localized. For more advanced disease, the benefits of surgery are unclear. Features which favor poor outcome include tumour size >2cm, high grade, poorly differentiated histology, invasion beyond the muscularis propria, lymphatic or vascular invasion, perineural invasion, and high mitotic index (high Ki67 index).

    Lesions < 1cm should be completely resected endoscopically or by another transanal technique. Lesions >2cm have a high risk of metastases (about 60-80%). It is unclear if radical surgery will improve patient outcome. Lesions between 1 and 2 cm have a metastatic potential between 10% and 15% and it is not certain whether radical surgery is more beneficial than local surgery. However, tumours with cellular atypia or invasion beyond the muscularis propria should be treated aggressively.

    Colonic NETs of the hindgut are treated similarly as adenocarcinoma by localized colectomy and resection of the lymph nodes.

Medical therapy

  1. Biotherapy
    Carcinoid syndrome is uncommon in hindgut NETs. In the uncommon case of a functioning hindgut NET, octreotide is indicated.
  2. Systemic chemotherapy
    This has limited value for slow-growing NETs, but may be indicated for poorly differentiated, fast-growing tumours (cisplatin-etopside).

References

  1. Crocetti E, Paci E. Malignant carcinoids in the USA, SEER 1992-1999. Anepidemiological study with 6830 cases. Eur J Cancer Prev 2003;12(3):191-4.

  2. Fjallskog ML, Granberg DP, Welin SL, Eriksson C, Öberg KE, Janson ET, Eriksson BK. Treatment with cisplatin and etoposide in patients with neuroendocrine tumours. Cancer 2001;92(5):1101-7.

  3. Florman S, Toure B, Kim L, Gondolesi G, Roayaie S, Krieger N, Fishbein T, Emre S, Miller C, Schwartz M. Liver transplantation for neuroendocrine tumours. J Gastrointest Surg 2004;8(2):208-12.

  4. Kaltsas G, Rockall A, Papadogias D, Reznek R, Grossman AB. Recent advances in radiological and radionuclide imaging and therapy of neuroendocrine tumours. Eur J Endocrinol 2004;151(1):15-27.

  5. Kaltsas G, Korbonits M, Heintz E, Mukherjee JJ, Jenkins PJ, Chew SL, Reznek R, Monson JP, Besser GM, Foley R, Britton KE, Grossman AB. Comparison of somatostatin analog and meta-iodobenzylguanidine radionuclides in the diagnosis and localization of advanced neuroendocrine tumours. J Clin Endocrinol Metab 2001;86(2):895-902

  6. Modlin IM, Lye KD, Kidd M. A 5-Decade Analysis of 13,715 Carcinoid Tumours. Cancer 2003;97:934-59.

  7. Modlin IM, Lye KD, Kidd M. A 50-year analysis of 562 gastric carcinoids: small tumour or larger problem? Am J Gastroenterol 2004;99(1):23-32.

  8. Moertel CG, Kvols LK, O'Connell MJ, Rubin J. Treatment of neuroendocrine carcinomas with combined etoposide and cisplatin. Evidence of major therapeutic activity in the anaplastic variants of these neoplasms. Cancer 1991;68(2):227-32.

  9. Moller JE, Connolly HM, Rubin J, Seward JB, Modesto K, Pellikka PA. Factors associated with progression of carcinoid heart disease. N Engl J Med 2003;348(11):1005

  10. Di Luzio S, Rigolin VH. Carcinoid Heart Disease. Curr Treat Options Cardiovasc Med 2000;2(5):399-406.

  11. National Comprehensive Cancer Network (NCCN). Clinical Practice Guidelines in Oncology. Neuroendocrine Tumours – v.1.2005. (accessed at http://www.nccn.org/professionals/physician_gls/PDF/neuroendocrine.pdf

  12. Nehar D, Lombard-Bohas C, Olivieri S, Claustrat B, Chayvialle JA, Penes MC, Sassolas G, Borson-Chazot F. Interest of Chromogranin A for diagnosis and follow-up of endocrine tumours. Clin Endocrinol 2004;60(5):644-52.

  13. Öberg K, Astrup L, Eriksson B, Falkmer SE, Falkmer UG, Gustafsen J, Haglund C, Knigge U, Vatn MH, Valimaki M; Nordic NE Tumour Group. Guidelines for the management of gastroenteropancreatic neuroendocrine tumours (including bronchopulmonary and thymic neoplasms). Part I – general overview. Acta Oncol 2004;43(7):617-25.

  14. Öberg K. Interferon in the management of neuroendocrine GEP-tumours: a review. Digestion 2000;62 Suppl 1:92-7.

  15. Öberg K, Astrup L, Eriksson B, Falkmer SE, Falkmer UG, Gustafsen J, Haglund C, Knigge U, Vatn MH, Valimaki M; Nordic NE Tumour Group. Guidelines for the management of gastroenteropancreatic neuroendocrine tumours (including 15 bronchopulmonary and thymic neoplasms). Part II – specific NE tumour types. Acta Oncol 2004;43(7):626-36

  16. Öberg K, Kvols L, Caplin M, Delle Fave G, de Herder W, Rindi G, Ruszniewski P, Woltering AE, Wiedenmann B. Consensus report on the use of somatostatin analogs for the management of neuroendocrine tumours of the gastroenteropancreatic system. Ann Oncol 2004;15:966-973.

  17. Öberg K, Eriksson B. Nuclear medicine in the detection, staging and treatment of gastrointestinal carcinoid tumours. Best Pract Res Clin Endocrinol Metab 2005;19(2):265-76.

  18. Plöckinger U, Rindi G, Arnold R, Eriksson B, Krenning EP, de Herder WW, Goede A, Caplin M, Wiedenmann B, Öberg K, Reubi JC, Nilsson O, Delle Fave G, Ruszniewski P, Ahlman H. Guidelines for the Diagnosis and Treatment of Neuroendocrine Gastrointestinal Tumours. Neuroendocrinology 2004;80:394-424.

  19. Plöckinger U, Wiedenmann B. Diagnosis of Non-Functioning Neuro-Endocrine Gastro-Enteropancreatic Tumours. Neuroendocrinology 2004;80 (Suppl. 1):35-38.

  20. Que FG, Sarmiento JM, Nagorney DM, et al. Hepatic surgery for metastatic gastrointestinal neuroendocrine tumours. Cancer Control 2002;9(1):67-79. Sutcliffe R, Maguire D, Ramage J, Rela M, Heaton N. Management of neuroendocrine liver metastases. Am J Surg 2004;187(1):39-46.

  21. Ramage JK, Davies AH, Ardill J, Bax N, Caplin M, Grossman A, Hawkins R, McNicol AM, Reed N, Sutton R, Thakker R, Aylwin S, Breen D, Britton K, Buchanan K, Corrie P, Gillams A, Lewington V, McCance D, Meeran K, Watkinson A on behalf of UKNETwork for Neuroendocrine Tumours. Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours. Gut 2005;54 Suppl 4:iv1-16.

  22. Roche A, Girish BV, de Baere T, Baudin E, Boige V, Elias D, Lasser P, Schlumberger M, Ducreux M. Trans-catheter arterial chemoembolization as first-line treatment for hepatic metastases from endocrine tumours. Eur Radiol 2003;13(1):136-40.

  23. Sarmiento JM, Heywood G, Rubin J, Ilstrup DM, Nagorney DM, Que FG. Surgical treatment of neuroendocrine metastases to the liver: a plea for resection to increase survival. J Am Coll Surg 2003;197(1):29-37.

  24. Sokmensuer C, Gedikoglu G, Uzunalimoglu B. Importance of proliferation markers in gastrointestinal carcinoid tumours: a clinicopathologic study. Hepatogastroenterology 2001;48(39):720-3.

  25. van der Horst-Schrivers AN, Wymenga AN, Links TP, Willemse PH, Kema IP, de Vries EG. Complications of midgut carcinoid tumours and carcinoid syndrome. Neuroendocrinology 2004;80 Suppl 1:28-32. 

b. Pancreatic Neuroendocrine Tumors

Added 15 July 2013


Pancreatic NETs are uncommon with an annual incidence of 0.4-1.2 per 100,000 population. The endocrine cells give rise to pNETs which account for less than 4% of pancreatic neoplasms. The tumours can occur at any age and both sexes are affected equally.

pNETs can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1; von Recklinghausen disease) and tuberous sclerosis complex (TSC) with the most common association , up to 80%, in MEN1 patients.

Current terminology divides pNETs into:

  1. Non-functional tumours - often present in a manner similar to adenocarcinomas of the pancreas
  2. Functional tumours - excess hormone production results in clinical syndromes (e.g. sometimes in the context of a 'carcinoid syndrome', characterized by facial flushing, diarrhea, bronchial constriction caused by high levels of circulating serotonin). Other syndromes occur as a result of different hormones being produced, for example:
    1. Insulinomas
    2. Gastrinomas
    3. VIPomas
    4. Somatostatinomas
    5. Glucagonomas

Diagnostic and Staging Work-Up

CT scan of the chest and abdomen/pelvis is recommended to assess the extent of local involvement and to exclude distant metastases. A pancreas-protocol CT scan or MRI is indicated if the patient is thought to be an operative candidate. If a mass is not clearly identified or if there is uncertainty regarding vascular involvement, an EUS should be performed.

If there appears to be an isolated pancreatic lesion, refer to a hepatobilliary surgeon who will determine if the disease is resectable or unresectable. A biopsy is not always required but may be performed if clinically indicated.

If there are obvious metastases, then the pancreatic mass or metastases can be biopsied percutaneously with ultrasound CT guidance or by endoscopic with fine needle aspiration. In patients who have carcinoid syndrome, a potential carcinoid crisis should be prevented by prophylactic administration of octreotide, given by constant intravenous infusion at a dose of 50 mcg/h for 12 hours prior to and at least 48 hours after the procedure.

PNETs should be staged using 111In-pentetreotide scintigraphy (octreotide scan). Those with negative octreotide scans can be imaged with MIBG scintigraphy.

All patients with PNETs should have 24-hour urinary 5-HIAA and chromogranin A (CgA) measured at diagnosis.

Biliary Decompression 

Patients presenting with jaundice and cholangitis should receive antibiotics and undergo biliary decompression, usually by ERCP.

Patients with jaundice only who are potentially operative candidates do not require stenting unless operative intervention will be delayed by > 1-2 weeks.

Patients without jaundice do not require stenting.

Primary Surgical Therapy

Surgical treatment of pancreatic cancer should be undertaken by surgeons having expertise and experience with these tumours.

For resectable pNETs: definitive resection of the primary tumour should always be performed whenever technically feasible. In patients who have carcinoid syndrome, a potential carcinoid crisis should be prevented by prophylactic administration of octreotide, given by constant intravenous infusion at a dose of 50 mcg/h for 12 hours prior to and at least 48 hours after the procedure.

Prophylactic cholecystectomy should be considered during any surgery for neuroendocrine tumours.

For localized, locoregional, or resectable metastatic pNETs, curative surgery should be considered if technically and clinically feasible.

For unresectable metastatic pNETs, cytoreductive surgery to achieve maximal debulking and palliation of symptoms should be considered if technically feasible and clinically appropriate.

Pathology (per College of American Pathologists 2012)

Specimen: specify

  • Type
  • Procedure

Tumour: specify

  • Site
  • Size
  • Histologic type
  • Histologic grade
  • Microscopic tumour extension
  • Margins
  • Treatment effect (if neo-adjuvant therapy given)
  • Lymph-Vascular invasion
  • Perineural invasion
  • Lymph nodes: number examined, number involved
  • pTNM (AJCC 7th edition)

In addition for pNETs:

  • Functional type
  • Mitotic rate (per 10 HPF)
  • Tumour necrosis
  • Ki-67labellilng index (≤ 2%, 3-20%, >20%)
  • Additional pathologic findings

​Treatment Options:

Treatment options are based on current evidence

Surgery

Surgery is the only curative treatment. Indications for surgery depend upon the size and location of the pNET. Surgical procedures include:

  • pancreaticoduodenectomy (Whipple’s resection: classic or pylorus-preserving)
  • distal pancreatectomy +/- splenectomy
  • tumour enucleation
  • enucleation combined with resection
  • regional lymph node dissection required for 'malignant' (high grade) pNETs

Patients with “limited” metastatic disease should be considered for surgery.

Patients with liver metastases from either functioning or non-functioning tumours where greater than 90% of the tumour mass can be removed may have a delay in disease progression.

Carcinoid crisis: hormonal release can occur with manipulation of the tumour(s) during surgery. A pre-operative anesthesia consultation is recommended and a peri-operative octreotide infusion is indicated.

Cholecystectomy should be done at the same time as any surgery to prevent complications from gallstone formation from any subsequent therapy with octreotide.

Cytoreductive Therapy

May be considered in symptomatic patients - selective embolization of hepatic arteries can reduce hormonal symptoms due to liver metastases.

Transarterial chemoembolization (TACE) involves injection of cytotoxic drugs (doxorubicin, 5FU or mitomycin C) intra-arterially with embolization material. This requires an assessment by a multidisciplinary team comprised of gastroenterologists, surgeons, radiologists and oncologists.

Transarterial radioembolization (TARE) is available at Vancouver General Hospital (VGH) and requires an assessment by the multidisciplinary team at VGH Liver Rounds. It involves injection of Yttrium-90 glass microspheres (see protocol UGIYTT).

Radiofrequency ablation (RFA) can be used to treat hepatic tumour masses of approximately 3 cm or less and, thus, reduce hormonal symptoms.

Systemic Therapy

Octreotide is the primary treatment for patients with symptomatic functioning pancreatic NET. About 80-90% of patients experience prompt improvement of their symptoms (see protocol UGIOCTLAR).

  • Caution should be taken with the use of octreotide in patients with insulinomas, since concomitant suppression of GH and glucagon can lead to a worsening of hyperglycemia.
  • A significant tumour regression may be observed in <10% of patients, but stabilization of tumour growth may occur in 30-50% of patients.
  • After a period of control, some patients may experience recurrence of their symptoms. The dose of octreotide should be increased or the interval between treatments reduced.

Chemotherapy with streptozocin and doxorubicin can reduce hormonal symptoms and slow progression of PNETs (see protocol GIENDO2).

Poorly-differentiated neuroendocrine tumours with a high proliferation index (Ki67 index greater than 20%) are treated with cisplatin and etoposide (see protocol GIPE).

Targeted agents have recently shown activity in the treatment of PNETs. Patients may be treated with one of the following:

The choice and sequence of systemic therapy is determined by disease-related factors, patient factors and patient preferences as assessed by the medical oncologist.

Consider treatment on a clinical trial, if available

Symptom management (including celiac or intrapleural block for tumour-related pain), best supportive care, and involvement of palliative care services as indicated by patient’s clinical status.

Somatostatin Receptor Radionuclide Therapy

Patients with progressive and/or symptomatic metastatic NETs whose tumours are receptor-positive as proven by an OctreoScan or MIBG scan, and have a ki67 less than or equal to 20% may be candidates for referral to a specialized centre for consideration of radionuclide therapy.

Follow-up:

Low-risk Resected Disease

  • All of the following: primary less than 2 cm, no nodal involvement, and low Ki67 index (<5%)
  • Low risk of recurrence
  • Follow up at the discretion of the treating physician

High-risk Resected Disease

Any of the following: primary greater than 2 cm, nodal involvement, high Ki67 (≥5%)

 Test

 Year 1

 Years 2-5

 5-HIAA (if functional)

 every 3 – 6 months

 every 3 – 6 months

 Chromogranin A

 every 3 – 6 months

 every 6 months

 CT scan

 annually

 annually

 Octreotide or  MIBG scan

 if any of the above are  abnormal

 if any of the above are  abnormal

 

Post-debulking with no visible residual disease

 Test

 Year 1

 Years 2 - 3

 Year 4-5

 5-HIAA (if  functional)

 every 3 – 6  months

 every 6 months

 annually

 Chromogranin  A

 every 3 – 6  months

 every 6 months

 annually

 CT scan

 annually

 annually

 annually

 Octreotide or  MIBG scan

 if any of the  above are  abnormal

 if any of the  above are  abnormal

 if any of the  above are  abnormal

 

Unresected disease (metastatic or residual-positive post-debulking)

 Test

 Year 1

 Years 2-5

 5-HIAA (if  functional)

 every 3 – 6 months

 every 4 – 6 months

 Chromogranin  A

 every 3 months

 every 4 - 6 months

 CT scan

 every 6 months

 every 6 months

 Octreotide or  MIBG scan

 if any of the above are  abnormal

 if any of the above are  abnormal

 Echocardiogram

 annually if 5-HIAA is  over 70 mg/24 hours

 annually if 5-HIAA is  over 70 mg/24 hours

 
SOURCE: Neuroendocrine Tumors ( )
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