Dr Lo Hau Ching Michelle Tuen Mun Hospital

Dr Lo Hau Ching Michelle Tuen Mun Hospital Joint Hospital Surgical Grand Round 14 Jan 2017

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ First labelled as “carcinoid” tumor by German pathologist Siegfried Oberndorfer in 1907 § A heterogenous group of neoplasms arising from the neuroendocrine system § Generally characterized by their ability to produce functional hormones or polypeptides § Leading to a wide variety of clinical presentation 1. 2. 3. Hallet, et al. "Exploring the rising incidence of neuroendocrine tumors: A population‐based analysis of epidemiology, metastatic presentation, and outcomes. " Cancer 121. 4 (2015): 589 -597. Delle Fave, et al. "ENETS consensus guidelines for the management of patients with gastroduodenal neoplasms. " Neuroendocrinology 95. 2 (2011): 74 -87. Sato, Yuichi, et al. "Management of gastric and duodenal neuroendocrine tumors. " World Journal of Gastroenterology 22. 30 (2016): 6817.

§ More than 50% of neuroendocrine tumor arises from gastrointestinal tract § Overall incidence § Gastric NET: § 0. 33/100000 (US data) § 1. 67/100000 (Japan data) § 6% of all neuroendocrine tumors § Duodenal NET: § 0. 19/100000 (US data) § 0. 17/100000 (Japan data) § 3. 8% of all neuroendocrine tumors 1. 2. 3. Hallet, et al. "Exploring the rising incidence of neuroendocrine tumors: A population‐based analysis of epidemiology, metastatic presentation, and outcomes. " Cancer 121. 4 (2015): 589 -597. Sato, Yuichi, et al. "Management of gastric and duodenal neuroendocrine tumors. " World Journal of Gastroenterology 22. 30 (2016): 6817. Yao, James C. , et al. "One hundred years after “carcinoid”: epidemiology of and prognostic factors for neuroendocrine tumors in 35, 825 cases in the United States. " Journal of Clinical Oncology 26. 18 (2008): 3063 -3072.

§ Increasing incidence worldwide resulting from widespread use of endoscopy and increasing awareness among clinicians and pathologists 1. Tsai, Hui-Jen, et al. "The epidemiology of neuroendocrine tumors in Taiwan: a nation-wide cancer registry-based study. " PLo. S One 8. 4 (2013): e 62487.

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ Anemia (72%) § GI bleeding (32%) § Abdominal pain (69%) § Carcinoid syndrome (11%): diarrhea, flushing, wheeze § Serotonin released by NET into portal circulation is metabolized by the liver § Carcinoid syndrome seldom occurs in primary GI-NET (unless in extensive liver metastasis) and it is more common in extra-GI NET (such as bronchial NET) § Associated autoimmune abnormalities § Atrophic gastritis (67%) § Pernicious anemia (58%) § Not uncommonly, as incidental finding on endoscopic examination or upon histological assessment 1. Gough, David B. , et al. "Diverse clinical and pathologic features of gastric carcinoid and the relevance of hypergastrinemia. " World journal of surgery 18. 4 (1994): 473 -479. 2. Hoffmann, K. Martin, Masayuki Furukawa, and Robert T. Jensen. "Duodenal neuroendocrine tumors: classification, functional syndromes, diagnosis and medical treatment. " Best Practice & Research Clinical Gastroenterology 19. 5 (2005): 675 -697. 3. Jayasena, Channa N. , and Waljit S. Dhillo. "Carcinoid syndrome and neuroendocrine tumours. " Medicine 41. 10 (2013): 566 -569.

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

1. Chan, David L. , et al. ”Neuroendocrine tumors: models for rare tumour management. ” Cancer Forum March 2015 Vol 39 Issue No 1.

1. Delle Fave, G. , et al. "ENETS consensus guidelines update for gastroduodenal neuroendocrine neoplasms. " Neuroendocrinology 103. 2 (2016): 119 -124.

§ Important to identify possible association with hormonal or hereditary syndromes (e. g. MEN) as this would guide further investigation or treatment § Gastrinoma (60%) § 15 -30% clinical Zollinger Ellison Syndrome § Rest of the gastrinoma are clinically silent § Most gastrinoma are found in “gastrinoma triangle” § Somatostatin rich NET (15 -20%) § Gangliocytic paraganglioma § Duodenal neuroendocrine carcinoma

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ Conventional endoscopy with white light imaging § Smooth hemispherical submucosal lesions § Polypoid lesions § Look for presence of background atrophic gastritis § Magnifying endoscopy with narrow band imaging (NBI) § Gastric mucosal pit structures preserved § Endoscopic ultrasonography (EUS) § Hypoechoic structure arising from submucosal layer 1. Sato, Yuichi, et al. "Management of gastric and duodenal neuroendocrine tumors. " World Journal of Gastroenterology 22. 30 (2016): 6817.

§ Conventional endoscopy with white light imaging § Smooth hemispherical submucosal lesions § Polypoid lesions § Central depression or crater as tumor grows § Magnifying endoscopy with narrow band imaging (NBI) § Duodenal mucosal pit structures preserved § Pit structures may be absent and replaced by cyan coloured, corkscrew shaped capillaries over the central depression § Endoscopic ultrasonography (EUS) § Hypoechoic structure arising from submucosal layer 1. Sato, Yuichi, et al. "Management of gastric and duodenal neuroendocrine tumors. " World Journal of Gastroenterology 22. 30 (2016): 6817.

1. Chak, Amitabh. "EUS in submucosal tumors. " Gastrointestinal endoscopy 56. 4 (2002): S 43 -S 48.

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ Conventional imaging § CT / MRI § Limited value for small type 1 and 2 gastric NET and duodenal NET in terms of cost-benefit ratio § PET with 18 -FDG (fluorodeoxyglucose) § May identify high grade neuroendocrine tumors as they are more metabolically active § Somatostatin receptor imaging § Octretide scan (Octreo. Scan) § PET with 68 -Gallium labelled tracers (-DOTATOC, -DOTANOC, DOTATATE) 1. Bushnell, et al. "Standard imaging techniques for neuroendocrine tumors. " Endocrinology and metabolism clinics of North America 40. 1 (2011): 153 -162. 2. Johnbeck, et al. "PET tracers for somatostatin receptor imaging of neuroendocrine tumors: current status and review of the literature. " Future Oncology 10. 14 (2014): 2259 -2277. 3. Maxwell JE, Howe JR. Imaging in neuroendocrine tumors: an update for the clinician. International journal of endocrine oncology. 2015; 2(2): 159 -168. doi: 10. 2217/ije. 14. 40.

§ Chromogranin A (Cg. A) § Elevated in 60 -100% of NET § Produced by chromaffin cells of the adrenal medulla, paraganglia, enterochromaffin-like cells and beta cells of pancreas § Serum level reflects tumor load § Serial measurement as the most important parameter for monitoring of disease status § 24 hr urine 5 -hydroxyindolacetic acid (5 -HIAA) § Serotonin metabolite excreted in urine § Elevated levels generally imply the presence of liver metastasis 1. Vinik AI, Woltering EA, Warner RR et al. NANETS consensus guidelines for the diagnosis of neuroendocrine tumor. Pancreas. 2010; 39: 713 -734.

§ Measurement of gut hormones § Gastrin – gastrinoma § Insulin – insulinoma § Other biochemical screening tests for MEN type 1 § Serum calcium § Parathyroid hormone § Prolactin § Insulin-like growth factor-1 (IGF-1) 1. Vinik AI, Woltering EA, Warner RR et al. NANETS consensus guidelines for the diagnosis of neuroendocrine tumor. Pancreas. 2010; 39: 713 -734.

§ Epidemiology § Clinical presentation § Classification § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ Endoscopic resection by means of EMR/ESD § Tumor size ≥ 10 mm § Wedge excision or partial gastrectomy § Positive resection margin § T 2 lesions (invades muscularis propria) or above § Somatostatin analogues (SSA) § No study comparing the use of SSA vs surveillance § Maybe useful in treatment multiple small lesions that are hard to eradicate on OGD § Netazepide § Gastrin receptor anatgonist § Antiproliferative properties in non-controlled studies

§ Treatment is usually dictated by possible presence of duodenal or pancreatic NET as part of MEN-1 § Local or limited excision is recommended § Use of Netazepide for type 2 NET is under trial

§ Follow the same management strategy as in gastric adenocarcinoma § Surgical treatment is recommended if feasible § Partial or total gastrectomy with LN dissection § Systemic therapies for inoperable or stage 4 disease

D-NETs: Duodenal neuroendocrine tumors; EUS: Endoscopic ultrasound; CT: Computed tomography; N+: Lymph node metastasis; M+: Distant metastasis; SRS: Somatostatin receptor scintigraphy; PRRT: Peptide receptor radionuclide therapy; SSA: Somatostatin analogues; CHT: Chemotherapy.

§ Epidemiology § Classification § Clinical presentation § Endoscopic features § Other investigations § Treatment options § Follow up strategy

§ Regular follow up is recommended but the exact time interval for surveillance endoscopy has not been well defined § In general, patients are recommended to repeat OGD at least every 2 years

§ Gastroduodenal neuroendocrine tumors is a rare disease entity § Endoscopic and relevant hormonal workup are essential § Endoscopic and surgical resection remains the cornerstone of therapy § Importance of regular follow up § Surveillance OGD § Monitoring of biochemical marker: chromogranin A

1. Tan, Huangying. "Advances in the diagnosis and treatment of gastric neuroendocrine neoplasms. " Translational Gastroenterology and Hepatology 1. 9 (2016).