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).

Effects of dialysis modality on blood loss, bleeding complications and transfusion requirements in critically ill patients with dialysis-dependent acute renal failure

Blood loss and bleeding complications may often be observed in critically ill patients on renal replacement therapies (RRT). Here we investigate procedural (i.e. RRT-related) and non-procedural blood loss as well as transfusion requirements in regard to the chosen mode of dialysis (i.e. intermittent haemodialysis [IHD] versus continuous veno-venous haemofiltration [CVVH]). Two hundred and fifty-two patients (122 CVVH, 159 male; aged 61.5±13.9 years) with dialysis-dependent acute renal failure were analysed in a sub-analysis of the prospective randomised controlled clinical trial-CONVINT-comparing IHD and CVVH. Bleeding complications including severity of bleeding and RRT-related blood loss were assessed. We observed that 3.6% of patients died related to severe bleeding episodes (between group P=0.94). Major all-cause bleeding complications were observed in 23% IHD versus 26% of CVVH group patients (P=0.95). Under CVVH, the rate of RRT-related blood loss events (57.4% versus 30.4%, P=0.01) and mean total blood volume lost was increased (222.3±291.9 versus 112.5±222.7 ml per patient, P <0.001). Overall, transfusion rates did not differ between the study groups. In patients with sepsis, transfusion rates of all blood products were significantly higher when compared to cardiogenic shock (all P <0.01) or other conditions. In conclusion, procedural and non-procedural blood loss may often be observed in critically ill patients on RRT. In CVVH-treated patients, procedural blood loss was increased but overall transfusion rates remained unchanged. Our data show that IHD and CVVH may be regarded as equivalent approaches in critically ill patients with dialysis-dependent acute renal failure in this regard.

Impact of octreotide long-acting release on tumour growth control as a first-line treatment in neuroendocrine tumours of pancreatic origin

BACKGROUND

Somatostatin analogues (SSA) are widely used in the treatment of patients with functioning and non-functioning neuroendocrine tumours (NET). The aim of our investigation was to evaluate the antiproliferative effect of SSA in patients with pancreatic NET.

METHODS

We retrospectively analysed records of 43 patients with pancreatic NET treated at our clinic with octreotide long-lasting release as a first-line therapy. The aim of our study was to investigate the overall best response according to the RECIST criteria, overall best response defined as disease control rate (SD+PR), response and disease control rate at 12 months, and time to tumour progression (TTP).

RESULTS

The mean age (± SD) of the patients (16 female/27 male) at initial diagnosis was 54.7 ± 11.86 years. At the start of therapy, 39 of 43 patients were classified as stage IV according to ENETS-TNM. Tumours were graded, based on MiB-1/Ki67 staining, as G1 (n = 8), G2 (n = 30) or unknown (n = 5). The octreoscan was positive in 37 patients, negative in 2 and unknown in 4 cases. Nineteen patients had functioning tumours, 24 patients had non-functioning tumours. Median overall survival was 98 months, and median TTP was 13 months. Analysis of grading showed a statistically significant influence on TTP when comparing the median TTP for Ki67 >10% with Ki67 <5% (p = 0.009) and Ki67 5-10% (p = 0.036).

CONCLUSION

SSA may be considered as a first-line treatment for antiproliferative purposes in metastatic NET of the pancreas. Patients with a proliferation index <10% displayed a more durable response compared to those with a higher proliferation index.

[Neuroendocrine tumours of the GI tract--data from the German NET Registry]

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.

Analysis of sporadic neuroendocrine tumours of the enteropancreatic system by comparative genomic hybridisation

BACKGROUND

Chromosomal instability is observed in a wide spectrum of human cancer syndromes. However, to date, little is known of the characteristic genetic changes in sporadic neuroendocrine tumours of the gastroenteropancreatic system.

AIMS AND METHOD

We have studied copy number aberrations (CNAs) in 26 sporadic neuroendocrine tumours of the enteropancreatic system (12 foregut and 14 midgut tumours) by comparative genomic hybridisation (CGH), allowing simultaneous evaluation of the entire tumour genome.

RESULTS

Nearly all tumours (25/26; that is, 96%) showed chromosomal imbalances, including full chromosomal aneuploidies, losses and gains of chromosome arms, interstitial deletions, and amplifications. Whereas gains of chromosomes 4, 5, and 19 were found in both foregut and midgut tumours, gains of chromosomes 20q (58%), 19 (50%), as well as 17p (50%), and partial losses of chromosomes 1p (42%), 2q (42%), 3p, 4q, and 6q (25% each) were frequently observed only in foregut tumours. In contrast, midgut tumours displayed less CNAs. Gains were detected for chromosomes 17q and 19p (57%). Most frequent losses affected chromosomes 18 (43%) and 9p (21%).

CONCLUSIONS

The results of our CGH analyses revealed new distinct candidate regions in the human genome associated with sporadic neuroendocrine tumours. Some of the genetic alterations were shared by foregut and midgut tumours while others discriminated between the two groups. Thus our results allude to the involvement of identical as well as discriminative genetic loci in tumorigenesis and progression of neuroendocrine neoplasms of the foregut and midgut. Based on these findings potential new candidate genes will be discussed.

New molecular aspects in the diagnosis and therapy of neuroendocrine tumors of the gastroenteropancreatic system

The nature and biology of neuroendocrine cells and of tumors derived therefrom have been the subject of intense research using cell biological and molecular approaches. Diagnostic procedures for establishing the diagnosis of a neuroendocrine tumor have been improved through the development of new serological markers and imaging procedures. Histopathological diagnosis has been refined by the introduction of a broad spectrum of marker proteins for different subtypes of neuroendocrine neoplasms. The high receptor specificity of somatostatin analogues such as octreotide or lanreotide has made these drugs valuable tools in diagnosis and therapy, and some of the achievements made as well as future directions are reviewed in this article. Another substance in use for therapy of neuroendocrine tumors is interferon-a, whose signal transduction mechanism has been investigated considerably during the past several years. In addition to biotherapy with somatostatin analogues and/or interferon-a, chemotherapy is an accepted strategy in the treatment of advanced neuroendocrine tumor disease derived from the foregut. In this context, streptozotocin has caught some attention due to its somewhat selective toxicity against neuroendocrine tumor cells. Some recent studies on the role of the glucose transporter isoform GLUT2 may provide insight into streptozotocin's action. The multiple endocrine neoplasia type-1 gene has recently been cloned, sequenced and identified as a gene potentially involved in the development of the familial cancer syndrome of multiple endocrine neoplasia type 1 (MEN-1). Mutations of this putative tumor suppressor gene have been described, and the abundance of mutations in MEN-1-related tumors as well as sporadic neuroendocrine tumors at MEN-1 locations have been demonstrated. Whether determination of MEN-1 mutations will be valuable for clinical routine is under investigation.