NEUROENDOCRINE TUMOURS Updated December 2015 by Dr. Doreen Ezeife (PGY-5 Medical Oncology Resident, University of Calgary) Reviewed by Dr. Cynthia Card (Staff Medical Oncologist, University of Calgary) DISCLAIMER: The following are study notes compiled by the above PGY-5 medical oncology residents and reviewed by a staff medical oncologist. They reflect what we feel is relevant knowledge for graduating medical oncology residents preparing for their final examination. The information has not been surveyed or ratified by the Royal College. Neuroendocrine (NE) cells are located in almost every body tissue. NE cells are part of the Diffuse Endocrine System (DES) that can release hormones in response to a variety of stimuli to regulate normal physiological functions. Neuroendocrine Tumors (NETs) arise from NE cells. NETs are most commonly found in the gastrointestinal tract and pancreas. The term “carcinoid syndrome” refers to the collection of symptoms that are precipitated by secretory NETs. The term “carcinoid” was introduced by Oberndorfer in 1907 to describe NETs. It was previously felt that these tumors were not truly cancerous, so the term carcinoid implied a benign tumor. Unfortunately, this has led to some misconception about NETs. NETs can display variable biological behaviors, ranging from benign to very aggressive tumors. A) PUBLIC HEALTH

EPIDEMIOLOGY - Incidence: 4.7 per 100,0001. - Mortality: Not well-described.

RISK FACTORS - Environmental/Chemical/Infections: Whether there is an association between bronchial NETs

and smoking is unclear. Causality has not been proven. - Genetic: most are sporadic but bronchial NETs can rarely occur in the setting of multiple

endocrine neoplasia type 1 (MEN1). Type 2 gastric NETs can occur in the context of MEN1. Most pancreatic NETs are sporadic but can be associated with MEN1, von Hippel Lindau, neurofibromatosis type 1, and tuberous sclerosis.

PREVENTION & SCREENING - Prevention: nothing described. - Screening: nothing described.

B) PRESENTATION & DIAGNOSIS

SYMPTOMS & SIGNS - Common Symptoms/Signs/Presentations: Organized by site of origin of NET.

! Stomach: • Type 1 – 70-80% of all gastric NETs. Arise from enterochromaffin-like

cells (ECL cells). Associated with chronic atrophic gastritis and pernicious anemia. Patients may be asymptomatic or may present with abdominal pain, anemia, or reflux symptoms.

• Type 2 – 5% of all gastric NETs. Occur in association with gastrinomas (Zollinger-Ellison syndrome), often in the setting of MEN1. Patients may present with hypergastrinemia symptoms of peptic ulcer disease.

• Type 3 – 20% of all gastric NETs and are usually the most aggressive. Local or hepatic mets is usually found on presentation. Fasting serum gastrin levels are usually normal in these patients.

! Lung • Patients with bronchial NETs can present with a carcinoid syndrome

(flushes, sweats, diarrhea) that is severe and prolonged. This usually occurs in patients that have liver mets as well. Flushes may be associated with disorientation, anxiety and tremor. The majority of tumours arise in the proximal airways and symptoms occur due to an obstructing mass causing bleeding or respiratory symptoms. Beware of inducing a carcinoid crisis in attempts to biopsy. The patient may require pretreatment with a somatostatin analogue prior to biopsy if there is a risk of inducing a carcinoid crisis. Bronchial NETs may be associated with a hilar or a perihilar mass on CXR. The minority of cases can present as a peripheral solitary pulmonary nodule. Some patients may present with a Cushing’s syndrome.

! Pancreas • 50-75% of pancreatic NETs are nonfunctioning while the rest are

functioning and may produce insulin, gastrin, glucagon, somatostatin or VIP. Gastrinomas and insulinomas are the two most common pancreatic NETs. See table 1 below for features of selected syndromes.

Table 1 – Features and Investigations of Selected Syndromes

! Small bowel – many patients are asymptomatic at presentation and the small bowel NET is found incidentally. Among symptomatic patients, abdominal pain is the most common presenting symptom. Some patients may present with a bowel obstruction, intussusception, or bowel ischemia. Liver mets is very common. Can present with a carcinoid syndrome (see table 1).

! Appendix – Most patients are asymptomatic. When the tumour occurs at the base of the appendix, they may cause bowel obstruction leading to appendicitis.

o NETs arising from the colon, rectum and GU tracts are usually nonsecretory and NOT associated with a carcinoid syndrome, even when they metastasize.

! Colon – usually asymptomatic unless the tumours are large. If there are symptoms, they are similar to colorectal adenocarcinoma symptoms of changes in bowel habits, obstruction or bleeding. Patients may also present with abdominal pain, anorexia or weight loss. The majority of colonic NETs are located in the right colon, particularly in the cecum.

! Rectum – vast majority are asymptomatic and found incidentally on rectal exam or endoscopy.

! GU – hindgut NETs arising from the renal or testicular systems have been described in case reports. These lesions typically present as an abdominal or testicular mass. Some can occasionally present with a carcinoid syndrome.

! Ovary – Primary NETs are usually unilateral and often arise within a cystic teratoma or dermoid tumour. In contrast, metastatic ovarian NETs are usually bilateral, originate in the small intestine and can present with peritoneal carcinomatosis. The ovary drains directly into the systemic circulation so ovarian carcinoids can produce carcinoid syndrome without hepatic mets. Some ovarian carcinoids can produce a hormone that decreases gut motility and causes severe constipation.

INVESTIGATIONS Laboratory: - Serum chromogranin A: useful marker for both functioning and nonfunctioning NETs - 24hr urine 5-HIAA: useful for the diagnosis and follow-up of NETs, especially mid-gut NETs.

Measure 24hr urine 5-HIAA even if not presenting with carcinoid syndrome symptoms. If elevated, patients need to be on surveillance for carcinoid heart disease.

- Other: specific to the secreted hormone – ex. Insulin for insulinoma, gastrin for gastrinoma, etc. - Parietal cell antibodies for stomach NETs - MEN1 is excluded with normal serum calcium, PTH and possibly pituitary hormones - Calcitonin, somatostatin - Serum acid phosphatase and HCG levels may be elevated in patients with hindgut NETs.

Pathology: - Well vs poorly differentiated appearance - Expression of NE markers such as synaptophysin and chromogranin on immunohistochemistry

(IHC) - Ki67 (+/- mitotic rate) to determine if G1, G2 or G3 - IHC staining for specific hormones as dictated by clinical presentation

Diagnostic Imaging: - Anatomic imaging with CT or MRI. - Conventional PET is not useful for well-differentiated NETs but can be useful for poorly

differentiated NETs. - Octreotide scan (using 111Indium-penetreotide scintigraphy): useful for both functioning and

nonfunctioning NETs. Octreotide scan avidity can predict response to octreotide therapy. - MIBG (metaiodobenzylguanidine) scintigraphy: some NETs will take up MIBG and not octreotide. - Consider Echocardiogram if concerned about carcinoid heart syndrome or elevated 24hr urine 5-

HIAA.

Diagnostic Procedures: may need to pursue endoscopy to obtain a tissue diagnosis. Beware of inducing a carcinoid crisis in attempts to biopsy suspected bronchial NETs. If there is a risk of inducing a carcinoid crisis, pretreat the patient with a somatostatin analogue.

PATHOLOGY & MOLECULAR BIOLOGY - Common Histology: WHO Classification 2010 is used for digestive tract NETs; the 2004 is used

for bronchial NETs. o Digestive tract NETs:

! Neuroendocrine tumor grade 1 (G1) (carcinoid) ! Neuroendocrine tumor grade 2 (G2) ! Neuroendocrine carcinoma (large cell or small cell type) ! Mixed adenoneuroendocrine carcinoma (MANEC) ! Hyperplastic and preneoplastic lesions

o Bronchial NETs: ! Typical carcinoid (1-2%): < 2 mitotic figures per 10 HPF; no necrosis ! Atypical carcinoid (0.1-0.2%): 2-10 mf/10HPF ! Large cell neuroendocrine tumour (3%) ! Small cell neuroendocrine tumour (20%) -> aka poorly differentiated

- Common Metastatic Sites: liver, omentum, ovaries - Relevant Molecular Biology: none known.

STAGING - TNM: There is a separate TNM staging system for NETs of the appendix, pancreas, stomach,

small bowel/ampulla of Vater, and colorectal primary sites3. - Other: European Neuroendocrine Tumour Society/World Health Organization Nomenclature and

classification for NETs2 o Well-differentiated:

! Low grade (G1) – mitotic count <2 per 10 high power field (HPF), Ki-67 <3% ! Intermediate grade (G2) – mitotic count 2-20 per HPF, Ki-67 3-20%

o Poorly differentiated: ! High grade (G3) – mitotic count >20 per 10 HPF, Ki-67 > 20%

C) TREATMENT Treatment of NETs has be divided into:

i) GastroEnteroPancreatic NETs (GEP-NETs) - The term “GastroEnteroPancreatic” (GEP-NETs) is now used to encompass the broad range of NETs arising from the GI tract or pancreas. GEP-NETs are subdivided into: - Pancreatic NETs - Midgut GEP-NETs (ie. Ileo-jejunal and appendix) - Other GEP-NETs (ie. Stomach and duodenal) ii) Colorectal NETs – arising from the colon or rectum. iii) Bronchial NETs – arising from the bronchopulmonary system.

GEP-NETs: PANCREATIC NETs - Bottom Line General Approach:

- Role of surgery/local therapies: - For pancreatic NETs (pNETs), surgery can be curative. Cytoreductive surgery can be considered

in the presence of liver mets if the majority of the tumour can be safely removed. Consider cytoreductive surgery in the presence of liver mets to delay disease progression.

- Patients with extensive liver mets with functional pNET can also be considered for liver-directed therapies such as radiofrequency ablation, embolization, chemoembolization and radiolabeled microspheres.

- Surgery can also be considered in cases of advanced symptomatology due to hormone excess state.

Biotherapy

- Somatostatin analogues are the primary treatment in patients with symptomatic functioning pNETs, particularly those of low proliferation (G1) (see PROMID study summarized in table below; also see CLARINET study listed in references). Somatostatin analogues may also delay tumour progression.

Chemotherapy and Targeted Agents

- Well-differentiated pNETs: o First-line therapy: Streptozocin-based chemotherapy is recommended for metastatic

pNETs. Streptozocin is used in combination with 5-FU or Doxorubicin. Capecitabine and temozolomide is also effective in metastatic pNETs.

o Historically, interferon has shown some effectiveness in pNET patients, especially in symptom-control, dating back to the 1980’s. However, the toxicity profile and inconvenient dosing of interferon have rendered it no longer recommended for treatment of pNET patients.

o Second-line therapy: Patients may be treated with targeted agents sunitinib or everolimus. Sunitinib and everolimus are generally considered after the failure of systemic chemotherapy. However, the choice and sequence of systemic therapy is determined by disease-related factors, patient preferences, potential therapy-related adverse effects and assessed by the medical oncologist.

o Third-line therapy: Patients with progressive and/or symptomatic NETs whose tumours are MIBG and/or octreotide-avid, and the avidity is durable, may be considered for peptide receptor radionuclide therapy (PRRT)1. This therapy is still considered largely experimental in most of the world.

o In Alberta, Dr Sandy McEwan and colleagues at the Cross Cancer Centre in Edmonton have been using PRRT since the late 1990’s in NET patients. Two PRRT’s are currently available: I-131 MIBG and Lutetium-177 Octreotide.

- Poorly-differentiated pNETs: o Patients with poorly-differentiated pNETs should be treated with cisplatin and etoposide

chemotherapy. o The majority of patients present with advanced disease but some can present with

localized disease amenable to surgical resection. Patients should be referred to medical oncology after surgery for consideration of adjuvant chemotherapy.

Prognosis: Well-differentiated pNETs have an overall survival rate of 80% at 5 years. Median survival for advanced well differentiated PNETs is 60 months. For poorly differentiated pNETs, median survival statistics are similar to what is quoted for other small cell cancers, with ~1 month without treatment, but 8-10 months with chemotherapy.

- Important Phase III Clinical Trials:

Placebo-controlled, double-blind, prospective, randomized study on the effect of octreotide LAR in the control of tumor growth in patients with metastatic neuroendocrine midgut tumors: a report

from the PROMID Study Group. Rinke A et al. J Clin Oncol. 2009;27(28):4656.

Regimen • Octreotide LAR 30mg intramuscularly q monthly vs placebo Mechanism of Action of Experimental Drug

• Somatostatin analog. Binds to somatostatin receptors and inhibits serotonin secretion

Primary Endpoint • TTP Inclusion/Exclusion Criteria

• Unresectable midgut NET with no prior systemic treatment • Well-differentiated histology • KPS > 60% • No curative therapeutic options

Size (N) • 85 patients randomized Results • Survival: HR for OS was 0.81

• DFS/PFS/TTP: median TTP in octreotide group vs placebo was 14.3 mos vs 6 mos, respectively

• Response Rate: X vs. X • Quality of Life:

Toxicity • Hematologic toxicity • Nausea/diarrhea • Fatigue • fever

Conclusion • Octreotide LAR significantly lengthens time to tumor progression compared with placebo in patients with functionally active and inactive metastatic midgut NETs. Because of the low number of observed deaths, survival analysis was not confirmatory.

Other Comments • Small numbers

Sunitinib malate for the treatment of pancreatic neuroendocrine tumors.

Raymond E et al. N Engl J Med. 2011;364(6):501.

Regimen • Sunitinib 37.5mg po od vs. placebo Mechanism of Action of Experimental Drug

• Tyrosine kinase receptor inhibitor. Inhibits multiple tyrosine kinase receptors including platelet-derived growth factors (PDGFRα and PDGFRβ), vascular endothelial growth factors (VEGFR1, VEGFR2, and VEGFR3), FMS-like tyrosine kinase-3 (FLT3), colony-stimulating factor type 1 (CSF-1R), and glial cell-line-derived neurotrophic factor receptor (RET).

Primary Endpoint • PFS Inclusion/Exclusion Criteria

• Well-differentiated pancreatic NET • Unresectable • ECOG 0 or 1

Size (N) • 171 patients Results • Survival: median OS for sunitinib vs placebo 30.5 mos vs. 24.4

mos, respectively. • DFS/PFS/TTP: median PFS for sunitinib vs placebo 11.4 mos vs.

5.5 mos, respectively. • Response Rate: Objective RR in sunitinib group vs placebo 9.3%

vs. 0%, respectively. • Quality of Life: no overall difference was noted between the two

arms. Toxicity • Diarrhea, nausea, vomiting, fatigue, asthenia Conclusion • Continuous daily administration of sunitinib at a dose of 37.5 mg

improved progression-free survival, overall survival, and the objective response rate as compared with placebo among patients with advanced pancreatic neuroendocrine tumors.

Other Comments • (e.g. any criticisms about the study)

Everolimus for Advanced Pancreatic Neuroendocrine Tumors (RADIANT-3)

Yao JC et al. N Engl J Med. 2011;364(6):514

Regimen • Everolimus 10mg po od vs placebo Mechanism of Action of Experimental Drug

• Mechanistic target of rapamycin (mTOR) inhibitor. Reduces protein synthesis and cell proliferation by binding to the FK binding protein-12 (FKBP-12), an intracellular protein, to form a complex that inhibits activation of mTOR (mechanistic target of rapamycin) serine-threonine kinase activity. Also reduces angiogenesis by inhibiting vascular endothelial growth factor (VEGF).

Primary Endpoint • PFS Inclusion/Exclusion Criteria

• Low-grade or intermediate-grade unresectable pancreatic NET • ECOG 0 or 1 • Prior antineoplastic therapy was NOT an exclusion criterion

Size (N) • 410 patients Results • Survival: hazard ratio for disease progression or death from any

cause with everolimus, 0.35 • DFS/PFS/TTP: median PFS for everolimus vs placebo 11.0 vs. 4.6

months, respectively.

Toxicity • Grade 1 or 2: Stomatitis, rash, diarrhea, fatigue, infections (primarily upper respiratory), pneumonitis, interstitial lung disease

• Grade 3 or 4: Anemia, hyperglycemia, stomatitis, thrombocytopenia, diarrhea, hypophosphatemia, and neutropenia.

Conclusion • Everolimus, as compared with placebo, significantly prolonged progression-free survival among patients with progressive advanced pancreatic neuroendocrine tumors and was associated with a low rate of severe adverse events.

Other Comments • (e.g. any criticisms about the study)

- Other Important Published Data: 1. PRRT: Kwekkeboom DJ, de Herder WW, Kam BL, et al: Treatment with the radiolabeled

somatostatin analog [ 177 Lu-DOTA 0 ,Tyr 3 ]octreotate: toxicity, efficacy, and survival. J Clin Oncol 2008; 26: 2124–2130.

2. CLARINET study: Caplin et al. Lanreotide in Metastatic Enteropancreatic Neuroendocrine Tumors. N Engl J Med 2014; 371:224-233.

GEP-NETs: MIDGUT NETs

- Midgut NETs are those arising from the midgut (lower jejunum, ileum and appendix).

- Bottom Line General Approach:

- Role of surgery/local therapies: - For midgut NETs confined to the bowel, surgery can be curative. Cytoreductive surgery can be

considered in the presence of liver mets if the majority of the tumour can be safely removed. Consider removal of the primary tumour even in the presence of mets to prevent intestinal obstruction or ischemic complications. If unresectable, selective chemoembolization with doxorubicin chemotherapy is a feasible option. Patients with liver mets can also be considered for radiofrequency ablation.

- There is no indication for adjuvant or neoadjuvant chemotherapy for jejuno-ileal NETs. - For appendiceal NETs, appendectomy can be curative if the tumour is located at the tip of the

appendix, is well-differentiated and is <2cm. A right hemicolectomy is indicated if: tumour is 1-2cm with positive or unclear margins or with deep meso-appendiceal involvement, vascular or perineural invasion is present, location of the tumour at the base of the appendix, histology is

consistent with goblet cell carcinoid or mixed endocrine-exocrine tumour. Tumours >2cm should be treated with right hemicolectomy.

- Patients with goblet-cell carcinomas of the appendix should be referred to a medical oncologist after surgical resection for consideration of adjuvant chemotherapy with FOLFOX (similar to adjuvant treatment of colonic adenocarcinomas). Biotherapy

- Somatostatin analogues are indicated for patients with functional midgut NETs, especially in patients with carcinoid syndrome; it is effective in 50% of patients (see PROMID study summarized in table below; also see CLARINET study listed in references). Somatostatin analogues may also delay tumour progression.

- Chemotherapy and Targeted Agents - Well-differentiated midgut NETs:

o Chemotherapy is generally not used in well-differentiated midgut NETs as the response rates are < 10%. Agents that can be considered are: single-agent doxorubicin or 5-FU, dacarbazine and the combination of dacarbazine, 5-FU and epiadriamycin.

o The role of targeted agents is currently being studied. o Patients with progressive and/or symptomatic NETs whose tumours are MIBG and/or

octreotide-avid, and the avidity is durable, may be considered for peptide receptor radionuclide therapy (PRRT)1. This therapy is still considered largely experimental in most of the world.

o In Alberta, Dr Sandy McEwan and colleagues at the Cross Cancer Centre in Edmonton have been using PRRT since the late 1990’s in NET patients. Two PRRT’s are currently available: I-131 MIBG and Lutetium-177 Octreotide.

- Poorly-differentiated midgut NETs: - For poorly-differentiated NETs, cisplatin plus etoposide chemotherapy may be effective.

- Carcinoid heart disease - Carcinoid heart disease should be followed with annual echocardiogram +/- MRI. Referral to a

cardiac surgeon is encouraged in patients with tricuspid and/or pulmonary valvular heart disease. The role of octreotide in suppressing 5-HIAA levels to protect against heart damage is controversial.

- Prognosis: - The prognosis of patients with metastatic distal small bowel NETs with liver mets is 10yr OS of

15-25%. - Most patients with appendiceal NETs present with localized disease and have 5yr OS of 85-95%.

- Important Phase III Clinical Trials: - See PROMID study summarized in table above.

- Other Important Published Data: 1. Caplin ME et al. Lanreotide in metastatic enteropancreatic neuroendocrine tumors (CLARINET).

N Engl J Med. 2014 Jul;371(3):224-33.

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.

OTHER GEP-NETs Stomach NETs

- Bottom Line General Approach:

- Localized/Adjuvant/Locally Advanced Disease: - For type 1 and type 2:

o <1 cm: surveillance with OGD yearly o Multiple or >1 cm: endoscopic resection, then yearly OGD o Locally advanced or recurrent: resection or antrectomy o For type 3 and poorly differentiated tumours, partial or total gastrectomy with lymph node

dissection. There is no standard for adjuvant or systemic treatment and depends on the clinical centre.

o Recurrent disease despite local resection: gastrectomy and LN dissection o Somatostatin analogues can control disease for type 1 and type 2.

- Metastatic Disease: o Somatostatin analogues can control the secretory symptoms of the tumour o Well-differentiated stomach NETs: streptozocin/5-FU chemotherapy is recommended. o Poorly-differentiated stomach NETs: platinum and etoposide.

- Prognosis: Type 1: recurrence-free survival of 24 months and 100% survival6. Types 2 and 3 are more likely to metastasize and so the prognosis is poorer, exact prognosis not well described.

- Important Phase III Clinical Trials: none. - Other Important Published Data: none.

Duodenal NETs

- Bottom Line General Approach: Surgical removal of the tumour or pancreaticoduodenal resection/Whipple’s procedure can be curative for localized disease.

- There is no standard for adjuvant or systemic treatment and depends on the clinical centre. - See “Metastatic Disease for stomach NETs” as systemic treatment is similar for duodenal NETs. - For gastrin-producing tumours, proton pump inhibitors should be used to control acid-related

symptoms. - Prognosis: The 5-year survival of duodenal NETs is felt to be similar to all GI foregut NETs

which is 80–95% for local disease, 65–75% with regional involvement only, and 20–40% for the 5–10% of patients with liver or distant disease.

- Important Phase III Clinical Trials: none. - Other Important Published Data: none.

COLORECTAL NETs These are NETs involving the colon and/or rectum.

- Bottom Line General Approach:

- Localized/Adjuvant/Locally Advanced Disease: - Colonic NETs > 2cm in size, tumours with muscularis invasion, and G3 tumours should be

treated according to colon adenocarcinoma guidelines (ie. Surgical resection with hemicolectomy).

- Rectal NETs > 2cm in size, T3 or T4 stage, with G3 grading, or lymph node-positive rectal tumours should be treated according to rectal adenocarcinoma guidelines (ie. Surgical resection with total mesorectal excision or abdominoperineal resection depending on distance from anal verge).

- Adjuvant chemotherapy after surgery can be considered for G3/poorly-differentiated tumours with incomplete resection, although the evidence is lacking.

- Metastatic Disease: - Carcinoid syndrome is uncommon in colorectal NETs and should be treated with somatostatin

analogues if occurring. Evidence is lacking for the use of somatostatin analogues as anti-tumour agents.

- Palliative surgery may be considered for debulking.

- Patients with extensive liver mets can also be considered for liver-directed therapies such as radiofrequency ablation, embolization, chemoembolization and radiolabeled microspheres.

- Well-differentiated colorectal NETs: o Systemic chemotherapy is rarely indicated for G1 or G2 colorectal NETs. In the setting of

progressive disease, streptozocin-based chemotherapy may be considered. There may also be a role for temozolomide-based chemotherapy.

o Anti-angiogenesis and mTOR inhibitors are not used for colorectal NETs outside the setting of a clinical trial.

o Patients with progressive and/or symptomatic NETs whose tumours are MIBG and/or octreotide-avid, and the avidity is durable, may be considered for peptide receptor radionuclide therapy (PRRT)1. This therapy is still considered largely experimental in most of the world. The evidence for PRRT in the colorectal NET population is minimal, but results in NETs arising from other sites are encouraging.

o In Alberta, Dr Sandy McEwan and colleagues at the Cross Cancer Centre in Edmonton have been using PRRT since the late 1990’s in NET patients. Two PRRT’s are currently available: I-131 MIBG and Lutetium-177 Octreotide.

- Poorly-differentiated colorectal NETs: platinum and etoposide. - Prognosis: Typically years. Exact prognosis not well described. - Important Phase III Clinical Trials: none. - Other Important Published Data: none.

BRONCHIAL NETs

- Bottom Line General Approach:

- Localized/Adjuvant/Locally Advanced Disease: - Complete surgical resection with parenchymal sparing is recommended. Wide resection margins

are not required. For elderly patients or patients who are poor surgical candidates, a bronchoscopic resection can be considered. Systematic lymph node dissection is recommended in lymph node positive disease.

- There is currently no role for adjuvant/neoadjuvant systemic treatment.

- Metastatic Disease: - Carcinoid syndrome can be treated with somatostatin analogues if occurring. - Well-differentiated colorectal NETs:

o Chemotherapy with capecitabine and temozolomide in many expert centres despite the lack of level I evidence for this.

o Anti-angiogenesis and mTOR inhibitors use in bronchial NETs are under investigation. o Patients with progressive and/or symptomatic NETs whose tumours are MIBG and/or

octreotide-avid, and the avidity is durable, may be considered for peptide receptor radionuclide therapy (PRRT)1. This therapy is still considered largely experimental in most of the world.

o In Alberta, Dr Sandy McEwan and colleagues at the Cross Cancer Centre in Edmonton have been using PRRT since the late 1990’s in NET patients. Two PRRT’s are currently available: I-131 MIBG and Lutetium-177 Octreotide.

- Poorly-differentiated colorectal NETs: platinum and etoposide.

- Prognosis: Typical Carcinoid: 94% 5yr OS. Atypical Carcinoid: 72% 5yr OS. D) OTHER REFERENCES (not previously sited above)

- (e.g. Alberta Health Services/Cancer Care Ontario/BC Cancer Agency Clinical Practice Guidelines, ASCO Guidelines, Canadian Cancer Statistics 2015, UpToDate)

- 1. Yao JC et al. One hundred years after "carcinoid": epidemiology of and prognostic factors for neuroendocrine tumors in 35,825 cases in the United States. J Clin Oncol. 2008;26(18):3063.

- 2. Uptodate - 3. American Joint Committee on Cancer 7th edition - 4. Alberta Cancer Guidelines

- 5. BC Cancer Agency Clinical Practice Guidelines - 6. European Neuroendocrine Tumour guidelines 2012