Petra Rümmele

Right Portal Vein Ligation Combined With In Situ Splitting Induces Rapid Left Lateral Liver Lobe Hypertrophy Enabling 2-Staged Extended Right Hepatic Resection in Small-for-Size Settings

Objective:To evaluate a new 2-step technique for obtaining adequate but short-term parenchymal hypertrophy in oncologic patients requiring extended right hepatic resection with limited functional reserve. Background:Patients presenting with primary or metastatic liver tumors often face the dilemma that the remaining liver tissue may not be sufficient. Preoperative portal vein embolization has thus far been established as the standard procedure for achieving resectability. Methods:Two-staged hepatectomy was performed in patients who preoperatively appeared to be marginally resectable but had a tumor-free left lateral lobe. Marginal respectability was defined as a left lateral lobe to body weight ratio of less than 0.5. In the first step, surgical exploration, right portal vein ligation (PVL), and in situ splitting (ISS) of the liver parenchyma along the falciform ligament were performed. Computed tomographic volumetry was performed before ISS and before completion surgery. Results:The study included 25 patients with primary liver tumors (hepatocellular carcinoma: n = 3, intrahepatic cholangiocarcinoma: n = 2, extrahepatic cholangiocarcinoma: n = 2, malignant epithelioid hemangioendothelioma: n = 1, gallbladder cancer: n = 1 or metastatic disease [colorectal liver metastasis]: n = 14, ovarian cancer: n = 1, gastric cancer: n = 1). Preoperative CT volumetry of the left lateral lobe showed 310 mL in median (range = 197–444 mL). After a median waiting period of 9 days (range = 5–28 days), the volume of the left lateral lobe had increased to 536 mL (range = 273–881 mL), representing a median volume increase of 74% (range = 21%–192%) (P < 0.001). The median left lateral liver lobe to body weight ratio was increased from 0.38% (range = 0.25%–0.49%) to 0.61% (range = 0.35–0.95). Ten of 25 patients (40%) required biliary reconstruction with hepaticojejunostomy. Rapid perioperative recovery was reflected by normalization of International normalized ratio (INR) (80% of patients), creatinine (84% of patients), nearly normal bilirubin (56% of patients), and albumin (64% of patients) values by day 14 after completion surgery. Perioperative morbidity was classified according to the Dindo-Clavien classification of surgical complications: grade I (12 events), grade II (13 events), grade III (14 events, III a: 6 events, III b: 8 events), grade IV (8 events, IV a: 3 events, IV b: 5 events), and grade V (3 events). Sixteen patients (68%) experienced perioperative complications. Follow-up was 180 days in median (range: 60–776 days) with an estimated overall survival of 86% at 6 months after resection. Conclusions:Two-step hepatic resection performing surgical exploration, PVL, and ISS results in a marked and rapid hypertrophy of functional liver tissue and enables curative resection of marginally resectable liver tumors or metastases in patients that might otherwise be regarded as palliative.

Minute Gastric Sclerosing Stromal Tumors (GIST Tumorlets) Are Common in Adults and Frequently Show c-KIT Mutations

Multifocal hyperplasia of interstitial cells of Cajal (ICC hyperplasia) is a precursor of hereditary gastrointestinal stromal tumors (GISTs) in patients with germline mutations of c-KIT or PDGFRA, but precursor lesions of sporadic GISTs have not been defined yet. Small hyalinizing stromal tumors of the proximal stomach (referred to in this study as GIST tumorlets) were collected prospectively from 98 consecutive autopsies and additional cases were retrieved from surgical pathology files (total n=57). GIST tumorlets were grossly detectable in 22.5% consecutive autopsies performed in individuals older than 50 years. All lesions were located in the cardia, fundus, or proximal body, and ranged in size from 1 to 10 mm (4 mm). Similar lesions were not detected in the antrum, duodenum, and the remainder of the bowel. Histologically, the spindle cell subtype comprised all cases, with hyalinization and calcification in 57% of cases. The spindle cells were immunohistochemically positive for vimentin, CD117, and CD34. Twenty-four cases yielded sufficient DNA for subsequent molecular analysis, which showed c-KIT mutations in 11 cases (46%) and PDGFRA mutations in 1 case (4%). Sporadic GIST tumorlets of the proximal stomach are common in the general population over the age of 50 years and frequently show somatic c-KIT mutations. GIST tumorlets probably represent the grossly recognizable counterpart of sporadic ICC hyperplasia caused by somatic c-KIT or PDGFRA mutations. Early hyalinization and calcification seems to confer limited growth potential, and complete regression of such lesions is common. GIST tumorlets likely represent preclinical (preneoplastic) lesions that need additional stimuli to evolve into clinical GISTs, raising the possibility of a hyperplasia-neoplasia sequence in the development of sporadic GISTs.

Fluorescence endoscopy for the detection of low and high grade dysplasia in ulcerative colitis using systemic or local 5-aminolaevulinic acid sensitisation

Background and aims: Longstanding ulcerative colitis (UC), especially in the presence of epithelial dysplasia, is associated with an increased risk of developing cancer. As dysplasia is not visible during routine endoscopy, at least 40–50 random biopsies in four quadrants every 10 cm are recommended. Fluorescence endoscopy after sensitisation with 5-aminolaevulinic acid (5-ALA) was assessed for the detection of dysplasia in ulcerative colitis by taking optical guided biopsies. 5-ALA is converted intracellularly into the sensitiser protoporphyrin IX which accumulates selectively in neoplastic tissue allowing the detection of dysplasia by typical red fluorescence after illumination with blue light. Methods: In 37 patients with UC, 54 examinations were performed with fluorescence endoscopy after oral (20 mg/kg) or local (either with an enema or by spraying the mucosa with a catheter) sensitisation with 5-ALA. A total of 481 biopsies of red fluorescent (n=218) and non-fluorescent (n=263) areas of the colonic mucosa were taken. Results: Forty two biopsies in 12 patients revealed either low grade (n=40) or high grade (n=2) dysplasia. Sensitivity of fluorescence for dysplastic lesions was excellent and ranged from 87% (95% confidence interval (CI) 0.73–1.00) to 100% (95% CI 1.00–1.00) after local sensitisation, in contrast with only 43% (95% CI 0.17–0.69) after systemic administration. Specificity did not differ for both forms of local sensitisation (enema 51% (95% CI 0.44–0.57) and spray catheter 62% (95% CI 0.51–0.73)); after systemic sensitisation specificity was 73% (95% CI 0.69–0.83). Negative predictive values of non-fluorescent mucosa for exclusion of dysplasia were very high; 89% after systemic sensitisation and 98–100% after local sensitisation. Positive predictive values were 13% and 14% after local sensitisation with enema and spray catheter, and 21% after oral sensitisation with 20 mg/kg ALA. The overall number of biopsies per examination was less than five from fluorescent positive areas. Conclusion: Fluorescence endoscopy after 5-ALA sensitisation is a possible tool to visualise dysplastic lesions in ulcerative colitis using 5-ALA sensitisation. Local sensitisation is a promising alternative approach compared with systemic administration of 5-ALA. A randomised controlled study is now indicated to compare the efficacy of endoscopic fluorescence detection with the standard technique of four quadrant random biopsies.

Glucose Transporter 1 Gene Expression is Related to Thyroid Neoplasms with an Unfavorable Prognosis: An Immunohistochemical Study

PURPOSE An accelerated rate of glucose metabolism mediated by overexpression of key regulatory glycolytic enzymes and glucose transporters is among the most characteristic biochemical marker of malignant transformed cells. In thyroid neoplasms, however, an increased uptake of glucose [measured by 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) and positron emission tomography (PET)] seems to be restricted to more aggressive and high-grade tumors, whereas tumors with favorable prognosis demonstrate no significant tracer uptake. We therefore studied the expression of glucose transporters in thyroid carcinomas with different grades of malignancy. METHODS Sections of formalin-fixed and paraffin-embedded tissue obtained from 45 patients with thyroid cancer (5 anaplastic, 20 papillary and 20 follicular tumors) were investigated. Polyclonal rabbit antiglucose transporter antibodies, reactive with glucose transporters 1-5 (GLUT1-5), were used after heat pretreatment of the sections. Staining was performed by the avidin-biotin conjugate immunoperoxidase reaction and evaluated semiquantitatively. RESULTS Expression of GLUT1 transporter on the cell membrane was closely related to the grade of malignancy in thyroid neoplasms (Fisher exact test p < 0.05). All anaplastic tumors showed a high level of GLUT1 expression in the cytoplasm and on the cell membrane. Positive membranous staining in differentiated tumors was detected predominantly in neoplasms with unfavorable prognosis, e.g., in widely invasive follicular or metastatic tumors, whereas low or no immunoreactivity could be seen in well-differentiated tumors or in normal thyroid epithelium. CONCLUSIONS These data indicate that overexpression of GLUT1 on the cell membrane of thyroid neoplasms is closely related to tumors demonstrating a more aggressive biological behavior. Therefore, determination of GLUT1 expression in thyroid cancer tissue may be a prognostic marker, and FDG-PET may be a helpful technique in identifying patients at a higher risk.

Ischemic-like cholangiopathy with secondary sclerosing cholangitis in critically Ill patients

OBJECTIVES:Sclerosing cholangitis in critically ill patients (SC-CIP) is a newly described entity of severe biliary disease with progression to liver cirrhosis. The mechanisms leading to this form of cholangiopathy with stricture formation and complete obliteration of bile ducts are unknown.PATIENTS AND  METHODS:In the last 2 yr, sclerosing cholangitis was diagnosed in 26 patients during or after their stay on the intensive care unit by ERCP and/or liver histology. Complete patient records were available for 17 patients. Histological evaluations of liver biopsies and of four explanted livers, parameters of cardiovascular and respiratory conditions, treatment modalities, and accompanying infections were analyzed to find further hints for the pathomechanisms leading to SC-CIP.RESULTS:With the beginning of cholestasis, the earliest endoscopic findings were intrahepatic biliary casts with impairment of the biliary flow and subsequent biliary infection, in most cases with Enterococcus faecium. Liver biopsy confirmed cholangitis and histology of explanted livers revealed ulcerated biliary epithelium with hemorrhagic exudates in the bile ducts. In the further course, progressive sclerosis with formation of multiple strictures of the bile ducts was observed. All patients suffered severe respiratory insufficiency with the need for mechanical ventilation (40.7 ± 32.9 days). The PaO2/FiO2 ratio until beginning of cholestasis was 150.5 ± 43.1. Half of the patients (9/17) were treated with high-frequency oscillatory ventilation and 12/17 patients by intermittent prone positioning. All patients required catecholamines for hemodynamic stabilization.CONCLUSIONS:SC-CIP is a severe and in most cases rapidly progressive complication of intensive care patients. Ischemic injury of the biliary tree with the formation of biliary casts and subsequent ongoing biliary infection due to multiresistant bacteria seem to be major pathogenic mechanisms in the development of this new entity of sclerosing cholangitis.

Google Goes Cancer: Improving Outcome Prediction for Cancer Patients by Network-Based Ranking of Marker Genes

Predicting the clinical outcome of cancer patients based on the expression of marker genes in their tumors has received increasing interest in the past decade. Accurate predictors of outcome and response to therapy could be used to personalize and thereby improve therapy. However, state of the art methods used so far often found marker genes with limited prediction accuracy, limited reproducibility, and unclear biological relevance. To address this problem, we developed a novel computational approach to identify genes prognostic for outcome that couples gene expression measurements from primary tumor samples with a network of known relationships between the genes. Our approach ranks genes according to their prognostic relevance using both expression and network information in a manner similar to Googles PageRank. We applied this method to gene expression profiles which we obtained from 30 patients with pancreatic cancer, and identified seven candidate marker genes prognostic for outcome. Compared to genes found with state of the art methods, such as Pearson correlation of gene expression with survival time, we improve the prediction accuracy by up to 7%. Accuracies were assessed using support vector machine classifiers and Monte Carlo cross-validation. We then validated the prognostic value of our seven candidate markers using immunohistochemistry on an independent set of 412 pancreatic cancer samples. Notably, signatures derived from our candidate markers were independently predictive of outcome and superior to established clinical prognostic factors such as grade, tumor size, and nodal status. As the amount of genomic data of individual tumors grows rapidly, our algorithm meets the need for powerful computational approaches that are key to exploit these data for personalized cancer therapies in clinical practice.

Analysis of intestinal haem-oxygenase-1 (HO-1) in clinical and experimental colitis.

Haem‐oxygenase‐1 (HO‐1) has been shown to exert anti‐inflammatory, anti‐apoptotic and anti‐proliferative effects. We investigated HO‐1 expression in patients with inflammatory bowel disease (IBD) and could demonstrate a scattered expression of HO‐1 in the intestinal epithelium of severely inflamed colonic mucosa of patients with IBD compared to control specimens such as diverticulitis, suggesting dysregulated expression in IBD. To further analyse potential mechanisms of HO‐1 induction in the intestine we employed an in vitro epithelial cell apoptosis model and an experimental colitis model. In vitro induction of HO‐1 by the HO‐1 inducer cobalt protoporphyrin (CoPP) resulted in a dose‐dependent down‐regulation of caspase‐3 activation in HT‐29 cells, indicating an anti‐apoptotic function of HO‐1 in the intestine. In vivo, preventive HO‐1 induction by CoPP in acute dextran sodium sulphate (DSS)‐induced colitis led to a significant down‐regulation of colonic inflammation (P < 0·01) with a concomitant reduction in interferon (IFN)‐γ − but unaffected interleukin (IL)‐10‐secretion by isolated mesenteric lymph nodes (P < 0·01). Additionally, TUNEL staining of colonic sections demonstrated fewer apoptotic epithelial cells in the colon of CoPP treated animals. No beneficial effects were observed if HO‐1 was induced by CoPP after the onset of acute colitis or in chronic DSS‐induced colitis. In conclusion, the data suggest a protective role of HO‐1 if it is induced before the onset of inflammation. However, as shown by the lack of effects in established acute or in chronic colitis, the induction of HO‐1 may not be a promising approach for the treatment of IBD.

Novel strategy for optimal sequential application of clinical criteria, immunohistochemistry and microsatellite analysis in the diagnosis of hereditary nonpolyposis colorectal cancer.

Clinical criteria, microsatellite analysis (MSA) and immunohistochemistry (IHC) are important diagnostic tools for identification of hereditary nonpolyposis colorectal cancer (HNPCC) patients who are likely to carry pathogenic germline mutations in mismatch repair genes. Based on MSA and IHC results and subsequent mutation analyses of 1,119 unrelated index patients meeting the Amsterdam II criteria or the classical Bethesda guidelines, we analyzed the value of these tools to predict MLH1 and MSH2 mutations with the aim of establishing optimal strategies for their most efficient sequential use. The overall prevalence of pathogenic germline mutations in our cohort was 20.6% (95% CI = 18.3–23.0%) and 61.8% (95% CI = 56.8–66.6%), respectively, after MSA/IHC‐based preselection. IHC was highly predictive (99.1%) and specific (99.6%) with regard to MSA. However, 14 out of 230 mutations (6%) escaped detection by IHC. Thus, IHC cannot be recommended to substitute MSA fully. Nonetheless, IHC is important to indicate the gene that is likely to be affected. To combine both methods efficiently, we propose a novel screening strategy that provides 2 alternative ways of sequential IHC and MSA application, either using IHC or MSA in the first place. A logistic regression model based on the age of the index patient at first tumor diagnosis and the number of fulfilled HNPCC criteria is used to allocate individual patients to that alternative pathway that is expected to be least expensive. A cost analysis reveals that about 25% of the costs can be saved using this strategy.

Elevated nuclear maspin expression is associated with microsatellite instability and high tumour grade in colorectal cancer.

Maspin, a member of the serpin family, has been reported to suppress metastasis and angiogenesis in breast and prostate cancers. Overexpression of maspin was associated with adverse prognostic features in several other tumours. In this study, expression of maspin was analysed in 41 colorectal carcinomas with high‐frequency microsatellite instability (MSI‐H) and 159 microsatellite stable colorectal cancers (MSS/MSI‐L) by immunohistochemistry (IHC) and partly by relative quantitative real‐time RT‐PCR and western blot analyses. Significant upregulation of maspin expression was found in MSI‐H tumours compared to both MSS/MSI‐L tumours and matched benign colonic mucosa. Increased maspin expression was also found in three MSI‐H colon cancer cell lines, but not in three MSS colon cancer cell lines by RT‐PCR and western blot analyses. Regulation of maspin expression depended on promoter methylation as tissue specimens and cell lines expressing maspin showed unmethylated maspin promoters, whereas promoter hypermethylation was found in specimens with loss of maspin expression. Intense nuclear maspin immunostaining was seen specifically in MSI‐H tumours (p = 0.013), de‐differentiated tumours (p = 0.006), and at the invasion front. These findings provide new insights into the role of maspin in colorectal cancer progression and may be useful for diagnosis and treatment strategies. Copyright

Induction of apoptosis before shedding of human intestinal epithelial cells

OBJECTIVES:Human intestinal epithelial cells (IECs) derive from stem cells at the crypt base and migrate along the so-called crypt-villus axis toward the intestinal lumen. As they reach the luminal surface in the colon or the villus tip in the small intestine, IECs are shed and their life cycle is terminated. The role of apoptosis during IEC migration along the crypt-villus axis has been subject to studies with conflicting results. In this study we use a novel approach to identify the initiation of apoptosis within normal human IECs.METHODS:Normal mucosa from the large and small human intestine was analyzed employing a novel antibody directed against activated caspase-3—an early marker of apoptosis.RESULTS:IECs initiate the apoptotic cascade as they approach the area of shedding before displaying evident morphological features of apoptosis. IECs of the small bowel also show caspase-3 activation in the small intestinal crypt base, whereas IECs of the colononic crypt base rarely show evidence of ongoing apoptosis.CONCLUSIONS:These findings indicate that apoptosis is initiated in human IECs as they reach the luminal surface/villus tip and before shedding. Furthermore, they show that different sections of the intestinal tract vary significantly in the rate of IEC apoptosis, possibly reflecting their difference in susceptibility to epithelial cell neoplasia.