Gastric neuroendocrine neoplasias: manifestations and comparative outcomes.

Although gastric neuroendocrine neoplasias (gNEN) are an orphan disease, their incidence is rising. The heterogeneous clinical course powers the ongoing discussion of the most appropriate classification system and management. Prognostic relevance of proposed classifications was retrospectively analysed in 142 patients from a single tertiary referral centre. Baseline, management and survival data were acquired for statistical analyses. The distribution according to the clinicopathological typification was gNEN-1 (n = 86/60.6%), gNEN-2 (n = 7/4.9%), gNEN-3 (n = 24/16.9%) and gNEN-4 (n = 25/17.6%), while hypergastrinemia-associated gNEN-1 and -2 were all low-grade tumours (NET-G1/2), formerly termed sporadic gNEN-3 could be subdivided into gNEN-3 with grade 1 or 2 and gNEN-4 with grade 3 (NEC-G3). During follow-up 36 patients died (25%). The mean overall survival (OS) of all gNEN was 14.2 years. The OS differed statistically significant across all subgroups with either classification system. According to UICC 2017 TNM classification, OS differed for early and advanced stages, while WHO grading indicated poorer prognosis for NEC-G3. Cox regression analysis confirmed the independent prognostic validity of either classification system for survival. Particularly careful analysis of the clinical course of gNEN-1 (ECLomas, gastric carcinoids) confirmed their mostly benign, but recurrent and extremely slowly progressive behaviour with low risk of metastasis (7%) and an efficient long-term control by repetitive endoscopic procedures. Our study provides evidence for the validity of current classifications focusing on typing, grading and staging. These are crucial tools for risk stratification, especially to differentiate gNEN-1 as well as sporadic gNET and gNEC (gNEN-3 vs -4).

[Endoscopic therapy for gastroduodenal neuroendocrine neoplasms]. / Endoskopische Therapie gastroduodenaler neuroendokriner Neoplasien.

Neuroendocrine neoplasms (NEN) represent a group of potentially malignant tumors, which can be located in every section of the gastrointestinal tract, the pancreas and the bronchopulmonary system. Gastroduodenal NENs have a relatively good prognosis in comparison to other subentities, e.g. pancreatic or ileojejunal NENs. In the stomach there are four different types of NENs, while in the duodenum there are five types and all vary in the malignant potential and the therapeutic approach. Due to the simple access endoscopic methods not only have diagnostic but also important therapeutic relevance in this subgroup. Lesions smaller than 1 cm can easily be resected with forceps or snare resection and for larger lesions up to 2 cm more invasive strategies, such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are available. Important criteria in gastric NEN for the risk evaluation of endoscopic treatment alone are the size of the lesion, depth of invasion and the tumor biology, e.g. neuroendocrine tumor (NET) G1/G2 versus neuroendocrine carcinoma (NEC) G3. In duodenal NEN the aforementioned risk factors also apply and in addition only lesions outside the ampulla of Vater should be endoscopically resected whereas periampullary lesions need to be addressed surgically. As an individualized therapeutic approach the possibility of a combined endoscopic and laparoscopic resection technique exists. Follow-up endoscopic investigations are necessary, especially in gastric type 1 NENs, which have a tendency to relapse.

[Neuroendocrine tumours of the GI tract--data from the German NET Registry]. / Neuroendokrine Tumoren des Verdauungstrakts - Daten des deutschen NET-Registers.

BACKGROUND: Neuroendocrine tumours (NET) are rare and heterogeneous neoplasia. To obtain valid data on epidemiology, diagnostics, therapy, prognosis and risk factors is the aim of the German NET registry. PATIENTS AND METHODS: Data from 2009 histologically proven NET were collected from 35 NET centres between 1999 and 2010. Data collection has been performed prospectively since 2004. Results: Median follow-up was 34.5 months and median age at diagnosis 56.4 years. Primary tumour localisations were pancreas (34.2%), midgut (5.8%), stomach (6.5%), bowel (6.9%), duodenum (4.8%) and neuroendocrine CUP (12.6%). Synchronous metastases were seen in 46% and second malignancies in 12%. From 860 patients, 402 (46.7%) had functional tumours with the following hormone excess syndromes: carcinoid syndrome (19.1%; n = 164), persistent hyperinsulinaemic hypoglycaemia (17.7%; n = 152), Zollinger- Ellison syndrome (7.1%; n = 61), glucagonoma (0.7%; n = 15), Verner-Morrison syndrome (0.4%; n = 8) and somatostatinoma syndrome(0.1%; n = 2). Surgical therapy was performed in 78%, therapy with somatostatin receptor analogues(SSA) in 28%, peptide radioreceptor therapy (PRRT) in 19%, chemotherapy in 18% and interferon therapy in 6.5%. Only surgery was done in 47%, whereas 53% received a second therapy. General mortality rate during follow-up was 14.9%. The tumour-specific survival rates for 2, 5 and 10 years were 94, 85 and 70%. The 5-year survival is dependent on the surgical or non-surgical therapy (82 versus 61%, p < 0.001) and also on the primary tumour site (90/30% for midgut, 85/65% for pancreas, p < 0.001). Grading (G1, G2, G3) based on proliferation index Ki-67 recommended by the ENETS guidelines and WHO classification is highly correlated to the 5-year survival rate (88, 82, 33%, p < 0.001). CONCLUSION: The German NET registry provides valid multicentric data on NET in Germany. Surgical therapy is the most frequent and important therapy with good clinical outcome. In non-resectable, metastatic tumours, systemic therapies are common. Continuation and evaluation of the new WHO and TNM classifications for NET and their therapies will be a future focus of the registry.