Aggressive surgery improves long-term survival in neuroendocrine pancreatic tumors: an institutional experience

OBJECTIVE: To evaluate surgical strategies for neuroendocrine pancreatic tumors (NEPT) in the light of the new WHO classification from 2004 and to draw conclusions for future surgical concepts. BACKGROUND:: The extent of surgical resection in primary and recurrent NEPT is unclear. METHODS: Between 1987 and 2004, 62 patients with sporadic NEPT were treated at our institution and sections from biopsy and resection specimen were histopathologically reclassified. Clinical presentation, surgery, metastases, and pattern of recurrence were related to survival. RESULTS: Fifteen well-differentiated tumors (WDT, 24%), 39 low-grade carcinomas (LGC, 63%), and 8 high-grade carcinomas (HGC, 13%) were identified. Median observation time was 30.5 months; 48 of 62 patients (78%) were surgically resected, and in 45 patients R0/R1 status was achieved. Overall 2- and 5-year survival in the latter group was 80% and 64%, respectively. Retrospective WHO classification revealed that organ-preserving segmental resections had been performed in 10 LGC and 1 HGC. These patients showed equal outcome as radically resected counterparts (n = 19). Liver and other organ metastases were present in 19 of 62 patients (31%), and resection was accomplished in 7 of 19 patients, which conferred better overall survival (P = 0.026, log-rank test); 21 of 45 R0/R1-resected patients (47%) suffered from recurrence, and reoperation was accomplished in 9 patients, which resulted in better overall survival (P = 0.066). CONCLUSION: Organ-preserving resections offer sufficient local control in LGC; therefore, radical resections do not seem to be justified. On the other hand, radical resection is indicated even in metastasized patients or in case of loco-regional recurrence. The silent and slow course of the disease facilitates long-term surgical control.     

L1 (CD171) is highly expressed in gastrointestinal stromal tumors.

The treatment strategy for mesenchymal tumors of the gastrointestinal tract is based upon typing of the tumor. Especially differential diagnosis of gastrointestinal stromal tumors (GISTs) to leiomyomas is crucial for determining radicality of surgery. L1 cell adhesion molecule (CD171) plays an essential role in tumor progression. The aim of this study was to determine expression of L1 in GISTs, smooth muscle tumors, desmoid-type fibromatosis and peripheral nerve sheath tumors (PNSTs). We retrospectively analyzed a total of 129 surgically resected primary tumors or metastases of 72 GISTs, 29 smooth muscle tumors, seven PNSTs and 21 desmoid-type fibromatosis by immunohistochemistry for c-kit, CD34, smooth muscle actin, desmin, vimentin, S-100 and L1 expression. L1 expression was detected in 53 (74%) of 72 GISTs but in none of 29 smooth muscle tumors or 21 desmoid-type fibromatosis (P<0.01 by Fisher's test). In all, four (57%) of seven peripheral nerve sheath tumors were L1-positive. Survival analysis of 55 surgically completely resected GISTs presenting without metastasis at initial diagnosis revealed no tumor-specific death among L1-negative patients (P=0.13 by log-rank test; median follow-up time 41 months) and one recurrence was observed (P=0.12). Interestingly high levels of L1 were seen in tumor vascular endothelial cells of smooth muscle tumors and PNSTs, but not in GISTs. Our data show that L1 is highly expressed in GISTs but not in smooth muscle tumors and desmoid-type fibromatosis being important differential diagnoses. The trend towards a reduced survival of L1-positive patients in this study has to be further evaluated in future trials with higher patient numbers.     

Diamond-Blackfan syndrome: evidence against cell-mediated erythropoietic suppression

The profound anemia of Diamond-Blackfan syndrome (DBS) is due to marrow red cell failure, but the pathogenesis is not understood. Studies by others indicated cell-mediated erythropoietic suppression in this condition. To explore this mechanism further, Ficoll-Hypaque--separated peripheral blood lymphocytes (PBL) from four anemic untreated patients with DBS, or from normals were cocultured with control marrow in vitro and the growth of erythropoietin-responsive stem cell colonies (CFU-E) was dermined. CFU-E numbers obtained from cultures with added normal PBL were not significantly different from the number without PBL. Similarly, CFU-E from cultures with added DBS PBL were not significantly different from the number without PBL (215 versus 220, 229 versus 220 and 84 versus 60, 74 versus 94/10(5) cells, respectively). Mixing marrows from a control and one DBS patient in ratios of 2:1, 1:1, or 1:2 prior to culture failed to disclose a decrease of colony growth. We could not show cellular inhibition of erythropoiesis in these patients with DBS. The mechanism of anemia in this disorder remains an open question.     

Lactobacillus rhamnosus CNCM I-3690 and the commensal bacterium Faecalibacterium prausnitzii A2-165 exhibit similar protective effects to induced barrier hyper-permeability in mice

Impaired gut barrier function has been reported in a wide range of diseases and syndromes and in some functional gastrointestinal disorders. In addition, there is increasing evidence that suggests the gut microbiota tightly regulates gut barrier function and recent studies demonstrate that probiotic bacteria can enhance barrier integrity. Here, we aimed to investigate the effects of Lactobacillus rhamnosus CNCM I-3690 on intestinal barrier function. In vitro results using a Caco-2 monolayer cells stimulated with TNF-α confirmed the anti-inflammatory nature of the strain CNCM I-3690 and pointed out a putative role for the protection of the epithelial function. Next, we tested the protective effects of L. rhamnosus CNCM I-3690 in a mouse model of increased colonic permeability. Most importantly, we compared its performance to that of the well-known beneficial human commensal bacterium Faecalibacterium prauznitzii A2-165. Increased colonic permeability was normalized by both strains to a similar degree. Modulation of apical tight junction proteins expression was then analyzed to decipher the mechanism underlying this effect. We showed that CNCM I-3690 partially restored the function of the intestinal barrier and increased the levels of tight junction proteins Occludin and E-cadherin. The results indicate L. rhamnosus CNCM I-3690 is as effective as the commensal anti-inflammatory bacterium F. prausnitzii to treat functional barrier abnormalities.     

Increased surface expression of the membrane glycoprotein IIb/IIIa complex induced by platelet activation. Relationship to the binding of fibrinogen and platelet aggregation

Platelet activation altered the binding of three monoclonal antibodies (monovalent Fab' fragment) directed against the glycoprotein (GP) IIb/IIIa complex. An increased binding of two- to threefold occurred after stimulation with thrombin or phorbol myristate acetate (PMA), with slight but significant increase in the dissociation constants (Kd) of two antibodies (LJ-CP8 and LJ-P9). In contrast, no statistically significant changes were observed with ADP-stimulated platelets. The increased binding of LJ-CP3, but not of the other two antibodies, to activated platelets decreased by 30% to 40% in the presence of EDTA at 22 to 25 degrees C. Platelets stimulated by thrombin or PMA bound more fibrinogen than did those stimulated by ADP, and significant differences in the extent but not in the affinity of fibrinogen binding were observed with various platelet agonists. When the pool of GP IIb/IIIa molecules exposed on the surface of unstimulated platelets was reacted with the monoclonal antibody LJ-CP3 to block ADP-induced fibrinogen binding and platelet aggregation, stimulation with thrombin or PMA still induced substantial binding of antibody and fibrinogen, and aggregation ensued. Therefore, platelets exposed to "strong" agonists exhibit an increased number of surface-oriented epitopes associated with GP IIb/IIIa. The GP IIb/IIIa molecules bearing these newly exposed epitopes are functional in that they can bind fibrinogen and mediate platelet aggregation.     

Pathogenesis and the natural course of chronic pancreatitis

This article gives an overview about current thinking in pathogenesis and natural course /therapy in chronic pancreatitis. Alcohol consumption is still the most relevant factor in the development of chronic pancreatitis, a disease with enormous personal and social impact, shortening life expectancy up to 10-20 yrs. Pathogenesis of chronic pancreatitis has to be considered for different symptoms. Particularly pain, the most bothering symptom, is most likely due to a combination of hypertension in the organ and parenchymal alterations. Pathogenesis of pancreatic head enlargement remains largely elusive. In particular it is not known what triggers growth factors to step into action. Most other symptoms like common bile duct stenosis or portal hypertension are secondary to this enlargement of the head of the pancreas.