Jörg Sturm

Long-term results of partial pancreaticoduodenectomy for ductal adenocarcinoma of the pancreatic head: 25-year experience.

The prognosis of patients who undergo resection for pancreatic ductal adenocarcinoma with curative intention is generally poor unless they have early-stage disease. Based on our 25-year experience, the results of 194 patients after a standardized Kausch-Whipple resection for adenocarcinoma of the pancreatic head were analyzed and the prognostic factors were evaluated. Between 1972 and 1998 a total of 221 patients were diagnosed for ductal adenocarcinoma of the pancreatic head, and 194 of them subsequently underwent a standardized Kausch-Whipple resection. Long-term results and prognostic factors were examined by multivariate and univariate analyses. The overall postoperative mortality was 3.09%, and the morbidity was 29.9%. By multivariate analysis only curative resection (R0) was significantly related to a favorable prognosis (p < 0.0001). Furthermore, in case of a curative resection, the presence of lymph node metastases showed prognostic significance in the multivariate analysis (p = 0.005). Cumulative survival analysis revealed a 5-year survival rate of 25.4%, a 7-year survival rate of 12.3%, and a 10-year survival rate of 8.2% for patients who underwent curative resection (R0) for adenocarcinoma of the pancreatic head. We demonstrated that the R0 status is the only independent prognostic factor after surgery for adenocarcinoma of the pancreatic head. In the case of a curative resection, the presence of lymph node metastases is of prognostic relevance. In view of considerable surgical morbidity and mortality, resection for cancer of the pancreatic head is the only option if the lesion is resectable. We concluded that surgical treatment is “as good as it gets,” as extended techniques have not proved to produce better results.

High expression of vascular endothelial growth factor predicts early recurrence and poor prognosis after curative resection for ductal adenocarcinoma of the pancreas.

Introduction and Aims Only curative resection for pancreatic adenocarcinoma is related to a favorable prognosis, but the overall survival after surgery still remains poor, and early recurrence is frequently observed. Because recurrence is the limiting factor and the main cause of death after curative resection, the identification of markers that predict early postoperative recurrence is of paramount importance. Angiogenesis is essential for tumor growth and metastases; therefore, we set out to clarify whether vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) correlate with early recurrence and poor prognosis after curative resection. A second goal was to characterize the VEGF-producing cells and the subcellular distribution. Methodology Seventy patients with ductal adenocarcinoma of the pancreas were studied after curative resection with a follow-up of at least 2 years. The MVD quantification was performed immunohistochemically with use of a monoclonal antibody to CD34. The VEGF expression was studied with use of polyclonal antibody. To detect the intracellular localization of specific VEGF mRNA sequences, nonisotopic in situ hybridization was performed. The correlations among VEGF expression and MVD, clinicopathologic parameters, and clinical outcome were then statistically analyzed. Results The VEGF immunoreactivity was 88.6%, and positive mRNA signals were obtained in the cytoplasm of carcinoma and endothelial cells in 81.4%. Furthermore, we observed tumor-associated macrophages close to infiltrating carcinoma cells. All endothelial cells showed positive immunoreactivity to the anti-CD34 antibody, and a median distribution of 85 vessels/×200 field was observed. A significant correlation (p < 0.05) was found between the MVD and the International Union Against Cancer (UICC) stage. Statistical analysis showed a significant correlation between VEGF expression and the height of MVD (p < 0.05). Kaplan–Meier analyses revealed that VEGF expression and MVD had a statistically significant correlation with survival after curative resection (p < 0.05). Furthermore, multivariate analysis indicated that VEGF expression is an independent prognostic marker for cancer recurrence within 8 months after curative surgery (p = 0.003). Conclusion In pancreatic adenocarcinoma, the VEGF expression and the height of MVD are closely correlated, and both—rather than UICC stage and TNM classification (tumor size and nodal involvement)—are markers of prognostic relevance after curative resection. Furthermore, VEGF is a predictor of early recurrence after curative resection. The current study indicates that VEGF may promote the distribution of metastases, leading to early cancer recurrence and poor outcome.

Prognostic implications of routine, immunohistochemical, and molecular staging in resectable pancreatic adenocarcinoma.

Cure for ductal adenocarcinoma of the pancreas is restricted to resectable tumors, but survival after surgery is still poor. Despite apparently curative resection, these cancers rapidly recur. Thus, the present pathologic examination should be enriched by sensitive methods to detect minimal residual disease. In a prospective setting we studied the frequency of minimal residual disease after curative resection by routine histopathology, immunohistology, and polymerase chain reaction (PCR) for mutated K-ras. Furthermore, the prognostic implication of detecting of MRD was determined. Prospectively, tumor tissue and corresponding paraaortic lymph nodes were obtained from 78 patients, who underwent surgery for pancreatic head tumors between 1999 and 2001. Sixty-nine of 78 cases were diagnosed for ductal adenocarcinoma (study group), whereas nine cases were diagnosed for benign pancreatic tumors (control group). Paraaortic lymph nodes were examined in step sections by routine histopathology (hematoxylin and eosin) and immunohistology using a pan-cytokeratin antibody. DNA of the primary tumor and corresponding paraaortic lymph nodes were analyzed by PCR-based assays with respect to mutated K-ras in codon 12. The recurrence-free survival and overall survival were correlated with the results of the latter methods. In 3 of 69 patients tumor cells were detected in paraaortic lymph nodes by routine histopathology and in 5 of 69 patients by immunohistology. K-ras mutations were detected in 42 of 69 ductal adenocarcinomas (61%), whereas 12 (17%) were positive in paraaortic lymph nodes. All of the latter patients had recurrence after surgery and a significant poorer survival than those without mutated K-ras. Furthermore, paraaortic lymph nodes diagnosed for K-ras mutation were independent prognostic markers in multivariate analysis. In the control group K-ras mutations were detected in one adenoma of Vaters papilla but not in paraaortic lymph nodes. Tumor cell DNA can be detected more sensitively by the described PCR method than with hematoxylin and eosin or immunohistologic staining, leading to a higher sensitivity for detection of micrometastases. The described PCR method clearly determines subgroups of patients after curative resection with early recurrence and poor survival and could therefore enrich the pathologic examination.

Microscopy of bacterial translocation during small bowel obstruction and ischemia in vivo--a new animal model.

BackgroundExisting animal models provide only indirect information about the pathogenesis of infections caused by indigenous gastrointestinal microflora and the kinetics of bacterial translocation. The aim of this study was to develop a novel animal model to assess bacterial translocation and intestinal barrier function in vivo.MethodsIn anaesthetized male Wistar rats, 0.5 ml of a suspension of green fluorescent protein-transfected E. coli was administered by intraluminal injection in a model of small bowel obstruction. Animals were randomly subjected to non-ischemic or ischemic bowel obstruction. Ischemia was induced by selective clamping of the terminal mesenteric vessels feeding the obstructed bowel loop. Time intervals necessary for translocation of E. coli into the submucosal stroma and the muscularis propria was assessed using intravital microscopy.ResultsBacterial translocation into the submucosa and muscularis propria took a mean of 36 ± 8 min and 80 ± 10 min, respectively, in small bowel obstruction. Intestinal ischemia significantly accelerated bacterial translocation into the submucosa (11 ± 5 min, p < 0.0001) and muscularis (66 ± 7 min; p = 0.004). Green fluorescent protein-transfected E. coli were visible in frozen sections of small bowel, mesentery, liver and spleen taken two hours after E. coli administration.ConclusionsIntravital microscopy of fluorescent bacteria is a novel approach to study bacterial translocation in vivo. We have applied this technique to define minimal bacterial transit time as a functional parameter of intestinal barrier function.

Influence of TNFA on the formation of liver metastases in a syngenic mouse model

The level of TNFα expression is increased after partial hepatectomy, and experimental evidence exists that TNFα plays a key role in liver regeneration. Contradictory results are reported about the influence of TNFα on tumor growth: on the one hand, stimulation of tumor growth in various animal models and, on the other hand, intraperitoneally administered TNFα leads to reduced metastasis formation. TNFα may be one responsible factor for increased metastasis formation after surgical trauma. The objective of our study was to clarify the influence of TNFα on the formation of liver metastases in a syngenic mouse model in vivo. We used a novel marker system, EGFP transfected C26 tumor cells for in vivo observation of metastasis formation by intravital microscopy. We analyzed the effect of intraperitoneal TNFα‐injection on tumor cell adhesion, extravasation and tumor development. The expression of ICAM‐1, VCAM‐1 and E‐Selectin was measured by Western blot and immunohistochemical staining. Tumor load was assessed by determining EGFP in Western blots. GdCl3 was employed 24 and 48 hr before tumor cell injection to selectively deplete the liver of functioning Kupffer cells. We observed significantly more extravasated tumor cells in the TNFα‐pre‐treated animals at early time points with increased expression of adhesion molecules. Measurement of the EGFP levels showed fewer liver metastases in the TNFα‐pretreated animals at day 8. After GdCl3 pretreatment even lower levels of EGFP, i.e., fewer metastases and also lower expression levels of ICAM‐1, VCAM‐1 and E‐Selectin could be observed. TNFα, acts in a bidirectional manner: whereas TNFα facilitates tumor cell adhesion and extravasation of C26 tumor cells by inducing the expression of adhesion molecules, at later time points, TNFα seems to hinder the formation of liver metastases.

The Gut Origin of Bacterial Pancreatic Infection during Acute Experimental Pancreatitis in Rats

Background: Infections are frequent complications and determine clinical course and outcome in severe pancreatitis. A novel animal model was used to assess minimal transit time of bacterial translocation (BT) across the gut mucosa in vivo using green fluorescent protein-transfected Escherichia coli and intravital video microscopy. Methods: Three hours after induction of acute pancreatitis by i.p. injection of 40 µg/kg cerulein, 0.5 ml of a suspension of green fluorescent protein-transfected E. coli were injected into the lumen of a small bowel reservoir formed by ligature in anesthetized Wistar rats. Translocation of E. coli was assessed by intravital microscopy. Animals were sacrificed 5 h after induction of pancreatitis. Results: BT across the mucosa and into the muscularis propria took a mean ± SD of 36.4 ± 8 min and 80.9 ± 9.5 min, respectively, in sham animals. Pancreatitis resulted in a significantly shorter minimal transit time across the mucosa (16.4 ± 4.9 min, p = 0.007) and into the muscularis propria (47.7 ± 2.5 min, p = 0.001). E. coli were detected on frozen cross-sections and on bacteriological examination of pancreatic tissue in animals with acute pancreatitis but not in controls. Discussion: Intravital microscopy of fluorescent bacteria is a new approach towards studying BT in vivo. Minimal transit time of BT serves as a novel functional aspect of mucosal barrier function during acute pancreatitis. The observation of fluorescent bacteria translocating from the small bowel lumen into the pancreas provides substantial experimental proof for the gut-origin-hypothesis of infectious complications in pancreatitis.

Liver regeneration in FGF‐2‐deficient mice: VEGF acts as potential functional substitute for FGF‐2

Background/Aims: The angiogenic properties, its role in mesoderm differentiation and cell culture studies implicate an important role of fibroblast growth factor (FGF‐2) in liver regeneration. The aim of the study was to evaluate this role in a FGF‐2 knockout mouse model.

Multimodal Treatment of Hepatocellular Carcinoma (HCC)

Screening of patients at risk for hepatocellular carcinomas (HCC) and preventive virustatic therapy are the first steps in a multimodal treatment concept, because delayed detection leads to a poor prognosis with median survival of <10 months. Surgical resection of HCC is still the treatment of choice in patients with good residual liver function, however, recurrence-free 5-year survival after curative resection is low (33%). In patients with cirrhosis, only 25% of HCC are resectable, limited by low hepatic functional reserve. HCC in patients with non-cirrhotic livers are the domain of extended resections. In newer reports, transplantation in patients with cirrhosis is rated more positively when restricted to patients with solitary nodules <5 cm or up to 3 tumors <3 cm. A new option in HCC therapy are the local methods for tumor ablation, preferably radiofrequency ablation (RFA), especially in patients with limited liver function, non-resectable or multifocal tumors. A new horizon is opened combining these options and multimodal approaches with transarterial chemoembolisation (TACE). This trend to multimodal approaches promises a yet unknown improvement in the prognosis of patients with HCC. Controlled randomized studies comparing and validating the different methods and defining combined treatments according to liver function and tumor stage are eagerly awaited.

The role of laparoscopy in the treatment of complications after colonoscopy.

Perforations of the colonic wall or splenic injury during colonoscopy are rare complications. Treatment of these complications by laparoscopy is an advisable compromise instead of an invasive surgery with a laparotomy or a noninvasive and potentially risky nonoperative therapy. All surgical procedures that can be performed by open approach can also be performed laparoscopically. We present in this report 15 patients who were treated for a perforation after colonoscopy. In addition, 2 cases of splenic injury after colonoscopy are described. Twelve perforations were sutured laparoscopically and 3 perforations were sutured via laparotomy. Except for 1 minor wound infection, there were no complications. One splenic injury was treated by spleen wrapping via an open approach due to former pancreatic surgery, and 1 injury was treated laparoscopically with a hemostypticum. Mortality was 0%. Early laparoscopic intervention is a safe and effective method in the treatment of serious complications after colonoscopy.

Enhanced green fluorescent protein-transfection of murine colon carcinoma cells: key for early tumor detection and quantification.

Many animal models for metastatic colorectal cancer represent clinical manifestations just inaccurately. We introduce a novel mouse model for metastastatic colorectal cancer. In order to remain close to the clinical disease a syngenic murine colon carcinoma cell line (colon 26 cells) was transfected with enhanced green fluorescent protein (EGFP). The transfected cells maintain the highly malignant attributes of the wild-type cells. Following injection into the portal circulation of Balb/c-mice, liver metastases occur in the same time span. Using the fluorescent attributes of the transfected cells, an approximation of the tumor load in liver tissue can be achieved by fluorescence activated cell sorting (FACS) and fluoroscan analysis. Tumor cell load in liver tissue can be accurately measured by Northern blot and Western blot analysis of liver tissue containing EGFP-transfected colon cancer metastases (1250 cells/mg liver tissue and 1000 cells/mg liver tissue) respectively. Confocal microscopy and intravital microscopy confirmed the growth of tumor metastases, originating from the intravascular compartments. The presented animal model using EGFP-transfected colon 26 cells allows the detecting of tumor growth in vivo and post mortem, as well as an accurate quantification of the tumor load in the liver tissue.