- Email: [email protected]
950 The Prognostic Superiority of Log Odds of Lymph Nodes in Stage III Colon Cancer
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that expression of SP is increased during chronic inflammation whereas NEP tissue levels are unaltered. In the SP pathway, it would appear that NEP is unable to sufficiently degrade the increased amount of SP, which may in part explain the perpetuation of pancreatic inflammation. Removal of pancreatic inflamed tissue, the “pacemaker” of neuroimmune inflammation, resulted in the reduction of the circulating level of SP, supporting the hypothesis of neuroimmune crosstalk in CP. Furthermore the correlation between serum and tissue levels of SP suggest that this neuropeptide might also represent a reliable marker of neurogenic inflammation in CP.
Signal Detection: A New Statistical Method to Predict NASH in Gastric Bypass Patients John M. Morton, Gavitt A. Woodard, Tina Hernandez-Boussard Background: Non-alcoholic steatohepatitis (NASH) is associated with morbid obesity, cardiac risk factor abnormalities, and metabolic syndrome. Currently, there are no adequate preoperative predictive models for NASH identification. We present a new statistical method to address this need. Methods: Signal detection affords the ability to identify patients at risk with both homogeneous outcomes and risk predictors and has been used in cardiac risk assessment. Potential risk factors for NASH were entered into the Signal Detection model by Kraemer et al. All patients underwent laparoscopic gastric bypass surgery with intraoperative liver biopsy at a single academic institution by a single surgeon. Preoperatively, liver function tests, cardiac risk factors, and comorbidities were assessed. We dichotomized liver pathology into NASH vs Steatosis (SS) per Brunt criteria for analysis by T-test or ChiSquare analysis as appropriate. Results: 141 patients successfully underwent laparoscopic Roux-en-Y gastric bypass surgery. Patient demographics were mean age, 45; female, 88%; mean BMI, 49; diabetic, 38%; hypertensive, 62%; and hepatitis or alcohol abuse, 0%. Liver biopsy results were Normal (2%), Steatosis (60%) and NASH (38%). The model identified the following variables in order as most discriminating in identifying patients with NASH: ALT>31, excess weight >109 kg, Lipoprotein A>21 and Hemoglobin A1C >6.9. This model identified this subgroup as having an 81% chance of having a pathologic NASH diagnosis. Conclusion: In this study, ALT, excess weight and hemoglobin A1C were correlated with NASH. This innovative new statistical technique affords a new ability to successfully identify gastric bypass patients with biopsy proven NASH.
948 The Role of ERCC1 RNA Expression in Blood As a Non-Invasive Predictor of Response to Neadjuvant Radio-Chemotherapy in Patients with Locally Advanced Cancer of the Esophagus Jan Brabender, Daniel Vallböhmer, Frederike C. Ling, Andreas C. Hoffmann, Georg Lurje, Elfriede Bollschweiler, Arnulf H. Hölscher, Paul M. Schneider, Ralf Metzger
780 Visceral Sensitivity Is Increased During the Initial Development of Postoperative Ileus in Mice Mario H. Mueller, Mia Karpitschka, Andrej Sibaev, Jörg Glatzle, Bing Xue, Michael S. Kasparek, Martin E. Kreis Introduction: Neurogenic, inflammatory and pharmacological alterations during surgery contribute to the pathophysiology of postoperative ileus (POI). We hypothesized that during the initial hours after surgery, afferent nerve fibers supplying the intestine are sensitized for the pain mediator bradykinin and mechanical stimuli which may contribute to efferent reflex inhibition of intestinal motility. We, therefore, aimed to explore intestinal afferent nerve sensitivity and motility during the early development of POI in mice. Methods: Under enflurane anesthesia, C57BL/6 mice underwent laparotomy followed by sham treatment or standardized small bowel manipulation to induce ileus. Then, after 1h, 3h or 9h, extracellular multi-unit mesenteric afferent nerve recordings were established In Vitro from 2 cm segments of jejunum (each subgroup n=6) continuously superfused with Krebs buffer (32°C, gassed with an O2/CO2 mixture). The segment was cannulated from both ends to monitor luminal pressure and intestinal motility simultaneously. Afferent discharge to luminal distension (080 cmH2O) and bradykinin (1µM) was recorded. Peak discharge frequency and intestinal motor events were analyzed by two-way ANOVA. Results: The mean amplitude of intestinal contractions was 0.8±0.2cmH2O 1 h after induction of POI and 5±0.8 cmH2O in segments taken after 1 h from sham controls (p<0.05). A similar difference was observed for segments harvested at the 3h and 9h time point (both p<0.05). Serosal bradykinin was followed by an increase in afferent discharge to 61±6 impsec-1 after 1h, 217±25 impsec-1 after 3h and 217±6 impsec-1 after 9h in ileus segments increased compared to 46±3 impsec-1 after 1h, 57±10 impsec-1 after 3h and 140±13 impsec-1 after 9h in sham controls (*P<0.05). The afferent response during ileus was augmented at high threshold luminal distension at 80 cmH2O (912±79 impsec-1 after 1h, 933±30 impsec-1 after 3h and 1131±63 impsec-1 after 9h) when compared to sham controls (639±39 impsec-1 after 1h, 714±40 impsec-1 after 3h and 1165±30 impsec-1 after 9h), (P<0.05). Conclusions: Afferent discharge to bradykinin and high pressure luminal distension is augmented in the early stage of postoperative ileus. As high-threshold mechanosensitivity and the algesic mediator bradykinin activate predominantly spinal afferents, spinal sensitization seems to occur at the initial stage of postoperative ileus which may trigger a reflex inhibition of intestinal motility perpetuating postoperative ileus.
949 Strong Prognostic Value of Nodal Microinvolvement in Patients with Carcinoma of the Papilla of Vater Receiving No Adjuvant Chemotherapy Dean Bogoevski, Paulus G. Schurr, Jussuf T. Kaifi, Guell Cataldegirmen, Oliver Mann, Yogesh K. Vashist, Emre F. Yekebas, Jakob R. Izbicki Background: To assess the prognostic significance of nodal microinvolvement in patients with carcinoma of the Papilla of Vater. Methods: From 1993 to 2003 at the University Clinic Hamburg, 777 patients were operated upon pancreatic and periampullary carcinomas. The vast majority of patients were operated upon pancreatic ductal adenocarcinoma (n=566, 73%), followed by carcinoma of the papilla of Vater (n=112, 14%), neuroendocrine carcinoma (n=39, 5%), IPMN (n=33, 4%) and distal bile duct carcinoma (n=27, 3%). Fresh-frozen tissue sections from 169 LN's classified as tumor free by routine histopathology from 57 patients with R0 resected carcinoma of the papilla of Vater who had been spared from adjuvant chemotherapy were immunohistochemically (IHC) examined, using a sensitive IHC assay with the anti-epithelial monoclonal antibody Ber-EP4 for tumor cell detection. With regard to histopathology, 39(63%) of the patients were staged as pT1/pT2, 21(37%) as pT3/pT4, 30(53%) as pN0, while 38(67%) as G1/G2. Results: Of the 169 “tumor free” LN's, 91 LN'S (53.8%) contained Ber-EP4-positive tumor cells. These 91 LN's were from 40(70%) patients. The mean overall survival in patients without nodal microinvolvement of 35.8 months (median-not yet reached) was significantly longer than that in patients with nodal microinvolvement (mean 16.6; median 13) (p=0.019). Multivariate Cox regression analysis for overall survival revealed that grading was the most significant independent prognostic factor (p=0.001), followed by nodal microinvolvement (p=0.013). Conclusions: The influence of occult tumor cell dissemination inLN's of patients with histologically proven carcinoma of the papilla of Vater supports the need for further tumor staging through immunohistochemistry.
781 Tissue and Serum Levels of Substance P Correlate in Patients with Chronic Pancreatitis Giuseppe Mascetta, Fabio Francesco di Mola, Federico Selvaggi, Massimo Falconi, Claudio Bassi, Nathalia Giese, Markus W. Buechler, Helmut M. Friess, Pierluigi Di Sebastiano The pathophysiology of pain in chronic pancreatitis (CP) is still unclear. Recent data suggest a role for neuropeptides such as substance P (SP) and the neuroimmune interaction in the inflammatory process of the pancreas. SP degradation is mediated by the endogenous extracellular metalloenzyme called neutral endopeptidase (NEP). Actually, no data are available regarding the relationship between tissue and serum levels of SP in CP. In this study we aimed to investigate a possible correlation between SP mRNA expression in pancreatic tissue and serum levels of SP in patients undergoing surgical resection for CP and to test the hypothesis that neuroimmune inflammation is a pathogenetic factor in CP. Materials and Methods. SP and NEP mRNA levels were analyzed by quantitative RT-PCR in pancreatic tissue specimens from 30 patients undergoing pancreatic resection for CP and 8 healthy organ donors. In addition, SP serum levels were determined before and after surgery and in 8 healthy individuals (control group) using an ELISA test. Results. Quantitative RT-PCR demonstrated increased SP mRNA expression in CP tissues (P<0.05) compared to controls, while NEP mRNA expression showed no significant changes between CP and healthy controls. The SP preoperative serum levels correlated with SP tissue levels in CP patients. After pancreatic resection, the majority of CP patients exhibited a significantly reduced expression of SP serum levels compared with preoperative levels. Conclusions: The present data show
950 The Prognostic Superiority of Log Odds of Lymph Nodes in Stage III Colon Cancer Jiping Wang, James M. Hassett, Merril T. Dayton, Mahmoud N. Kulaylat Background: Recent literature has shown that lymph node ratio (LNR) and log of odds (LODDS) of positive lymph nodes (LN) can equally predict prognosis in patients with breast cancer. We hypothesize that in patients with stage III colon cancer, LODDS is even superior to LNR. Methods: 24,477 stage III colon cancer cases from SEER are included. Based on
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Background: Only patients with locally advanced cancer of the esophagus with a major response to neadjuvant radio-chemotherapy do benefit from this treatment. Unfortunately, no non-invasive molecular marker exists that can reliably predict response to neadjuvant therapy in this disease. To improve the treatment of patients with cancer of the esophagus, molecular predictors of response are desperately needed. Aim of this study was to determine the value of ERCC1 RNA-Expression in peripheral blood of patients with cancer of the esophagus as a non-invasive molecular predictor of response to neoadjuvant therapy. Material and methods: A total of 29 patients with locally advanced cancer of the esophagus were included in this study. Blood samples were drawn from each patient prior to neoadjuvant therapy (cis-Platin, 5-FU, 36Gy). Transthoracic en-bloc esophagectomy was performed in all patients following completion of neadjuvant therapy. After extraction of cellular tumorRNA from blood samples, quantitative expression analysis of ERCC1 and the internal reference gene beta-Actin was done by real-time RT-PCR. Histomorphological regression was defined as major response when resected specimen contained <10% of residual vital tumor cells, and minor response with >10% of vital residual tumor cells. Results: Nineteen of 29 (65.5%) patients showed a minor histopathological response and 10(34.5%) showed a majorresponse to neadjuvant therapy. ERCC1 RNA expression in blood of patients was detectable for ERCC1 in 82.8% and 100% for beta-Actin. The median ERCC1 expression was 0.62 (min.: 0.00, max.: 2.48) in minor-responders and 0.24 (min.: 0.00, max.: 0.45) in majorresponders (p=0.004). No significant associations were detected between ERCC1 expression levels and patients clinical variables (histology, tumor stage, gender etc.). Relative ERCC1 expression levels above 0.452 were not associated with major histopathological response (sensitivity: 68.4; specificity: 100%) and 13 of 19 patients with minor response to the delivered neadjuvant therapy could be unequivocally identified. Conclusion: The applied method is technically feasable for the analysis of cellular ERCC1 RNA expression in blood of patients with cancer of the esophagus. Minor-responders to the applied therapy show a significant higher ERCC1 expression level in their blood compared to major-resonders prior to therapy. ERCC1 expression levels in blood appear to be highly specific to predict minorresponse to neoadjuvant radiochemotherapy in patients with esophageal cancer and could be applied to prevent expensive, noneffective, and potentially harmful therapies in a substantial number (45%) of patients.
LNR, patients are categorized into four groups, LNR1 to 4, according to cutoff points 1/14, 0.25 and 0.50 and on LODDS, patient are divided into five groups, LODDS 1 to 5, according to cutoff points -2.2, -1.1, 0 and 1.1. Kaplan-Meier and Cox proportional hazard model were used to evaluate the prognostic effect and estimate the relative risk (RR) and 95% confidence interval (CI). Results: In stage III colon cancer, both LNR and LODDS are in agreement in staging patients except LNR4. When stratify LNR4 into LODDS4 and LODDS5, patients have significant different 5-year survival (33.5% vs. 23.3%, p<0.0001). The observed 5-year survival for stage IIIB patients classified as LODDS1 to LODDS5 is 63.7%, 54.4%, 44.4%, 35.8% and 30.6% respectively (p<0.0001). On the other hand, the observed 5-year survival for patients with stage IIIC diseases who are classified as LODDS2 to LODDS5 is 49.7%, 41.7%, 29.8% and 18.8% respectively (p<0.0001). Univariate analysis shows that LODDS, LNR, age, race, number of negative LN (NNLN) or total number of LN examined (TNLN), tumor grade, size, and number of positive LN are significantly associated with survival. Whereas, in the multivariate Cox model, NNLN or TNLN, and LNR are not independently associated with survival after adjusting for LODDS. Conclusion: Patients with stage IIIB and IIIC colon cancer represent a heterogeneous group of patients with the majority either over-staged or under-staged. Patients with LNR4 also represent a heterogeneous group. In patients with stage III colon cancer, LODDS is a more accurate prognostic method than AJCC N staging, NNLN, and TNLN. Multivariate Cox model
952 VEGF Gene Therapy Improves Anastomotic Healing in the Gastrointestinal Tract: Applications in Esophageal Surgery Kristian Enestvedt, Shelley R. Winn, Brian S. Diggs, Luke Hosack, Barry Uchida, Robert W. O'Rourke, Blair A. Jobe Background: Anastomotic leak related to ischemia is a source of significant morbidity and mortality. The aim of this study was to utilize VEGF gene therapy for the purpose of upregulating angiogenesis, increasing anastomotic strength, and ultimately preventing dehiscence. Methods: An opossum esophagogastrostomy model was employed. The vascular endothelial growth factor (VEGF165) gene was incorporated into a circular recombinant plasmid. The plasmid was complexed with a non-viral synthetic vector, Jet-PEI. Control animals received plasmid devoid of VEGF165 (n=6). The experimental group received VEGF165 plasmid (n=5). After esophagogastrectomy and gastric tubularization, plasmid was injected into the submucosa of the neoesophagus at the anastomotic site. Conduit arteriography was performed before and 10 days after injection. Euthanasia occurred on post-injection day 10 and the anastomosis was removed en bloc. Blood flow was measured with laserDoppler prior to euthanasia. Ex vivo anastomotic bursting pressure was performed. Tissue samples were procured for RNA extraction and Factor VIII staining. Microvessel counts were obtained by 2 blinded observers. VEGF mRNA transcript levels were measured with quantitative RT-PCR using custom primers. Results: There were no deaths in either group. There was one leak in the control group. Experimental animals demonstrated significantly increased bursting pressure and neovascularization compared to controls (Table). In addition, there was a strongly positive correlation between the number of microvessels and bursting pressure (r=0.808, p=0.015, Pearson's). On angiographic examination, treated animals demonstrated more neovascularization compared to controls. RT-PCR demonstrated a 2.1 fold increase in VEGF mRNA tissue transcript levels in treated animals compared to controls (p=0.05, t-test). Discussion: This first description of successful gene therapy in the gastrointestinal tract using VEGF165 transfection demonstrates improved anastomotic healing in a clinically relevant model which may directly translate to human application.
*all numbers are mean values 953 Loss of Heterozygosity Portends Poor Survival of Patients with Resected Periampullary Cancer Jan Franko, Alyssa M. Krasinskas, Marina N. Nikiforova, Yuri E. Nikiforov, Steven J. Hughes, Kenneth K. Lee, David L. Bartlett, Herbert Zeh, Arthur J. Moser
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951 High Expression of Heparanase Is Significantly Associated with Dedifferentiation and Lymph Node Metastasis in Patients with Pancreatic Ductal Adenocarcinomas and Correlated to PDGFA and Via HIF1a to HB-EGF and bFGF Andreas C. Hoffmann, Ryutaro Mori, Daniel Vallbohmer, Jan Brabender, Uta Drebber, Stephan E. Baldus, Mizutomo Azuma, Ralf Metzger, Christina Hoffmann, Arnulf H. Hölscher, Kathleen D. Danenberg, Klaus L. Prenzel, Peter V. Danenberg
Background: Traditional AJCC staging system for periampullary adenocarcinoma has been well validated but improvements in prognostic accuracy are still needed. We hypothesized that molecular and genetic methods may predict biological behavior and postoperative survival independently of stage. Methods: Pancreatic ductal and ampullary carcinomas treated by pancreaticoduodenectomy in 2006 (n=50) were subjected to laser capture microdissection followed by loss of heterozygosity (LOH) analysis at 14 different chromosomal loci including 5q (APC), 6q (thrombospondin), 9p (p16), 10q (Pten), 12q (MDM2), 17p (p53), and 18q (DDC/DPC4). Mutations at k-ras exon 1 (codons 12 and 13) were assessed by PCR. The relationship between genetic alterations and clinical outcome was studied. Results: Negative resection margins were achieved in 43 (86%) cases. AJCC stage distribution was: Ia/b (3), IIa (16), IIb (29), and III (2). K-ras mutations were observed in 31 cases (62%). Allelic losses were identified in 26 (52%) with a median fractional allelic loss score of 18% (range 7-64%). There was no concordance between LOH and k-ras mutations (McNemar p=0.405). Survival was significantly shorter in patients with allelic losses (17.5 versus 21.2 months; p=0.039). Both higher AJCC stage (HR=1.29, p=0.018) and presence of LOH (HR=6.60, p=0.027) were identified as independent predictors of shorter survival in a Cox regression model. Increased fractional allelic loss portended worsened survival (HR=1.043 per percent loss, p=0.034), whereas age and k-ras mutations did not. Conclusion: Loss of heterozygosity predicts survival independently from stage in resected periampullary cancer. Allelic losses indicate more aggressive tumor biology and may improve risk stratification in future clinical trials.
Background: Pancreatic cancer still has the worst prognosis of all cancers with a 5-year survival rate of 5%. Due to late symptoms of pancreatic cancer and therefore often late diagnosis, only 10-20% of the patients are eligible for complete resection with curative intention, making it necessary to find markers or gene-sets which would further classify patients into different risk categories and thus allow more individually adapted multimodality treatment regimens. Some of the most promising genes described also in other entities are linked to angiogenesis. Especially HPSE has recently been discussed as a key factor in pancreatic cancer. Materials and Methods: Paraffin-embedded tissue samples were obtained from 41 patients with pancreatic adenocarcinoma with a median age of 65 years (range 34 - 85 years) at time of operation who were scheduled for primary surgical resection. After laser capture microdissection direct quantitative real-time reverse transcriptase PCR (RTPCR, TaqMan™) assays were performed in triplicates to determine HPSE, HIF1a, PDGFA, HB-EGF and bFGF gene expression levels. Gene expression was normalized with betaActin. Decision tree analysis and the maximal chi-square method were adapted to determine which gene expression value best segregated patients into lymph node negative and positive, and high and low dedifferentiation subgroups. Results: HPSE was significantly correlated to PDGFA (p=0.04) and to HIF1a (p=0.04). The correlation of HIF1a to bFGF and HBEGF expression was significant (p = 0.04, p = 0.02). We put all clinical, histopathological parameters and the used genes as independent variables in a stepwise multiple linear regression model with lymph node metastasis as the dependent variable. The overall model fit had a significance level of p = 0.029 (<0.05) with HPSE as the only significant predictor of lymph node metastasis, though pT was almost included. Using a stepwise multiple regression analysis to evaluate the most influential of the accessible factors on the dedifferentiation of the tumor the overall model fit was significant at a level of p = 0.003 (<0.05). The most significant independent factor was HPSE for predicting the grade of dedifferentiation. Conclusions: Considering the fact that Heparanase seems to be a highly significant independent variable for lymph-node metastasis (p = 0.029; <0.05) as well as for dedifferentiation (p = 0.003; <0.05) we assume that HPSE plays a crucial role for the aggressiveness of pancreatic cancer. Though these results were obtained on a relatively small number of patients, larger studies including patients treated with actual chemotherapeutics seem to be warranted.
Survival of patients with resected periampullary cancer stratified by LOH status.
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that expression of SP is increased during chronic inflammation whereas NEP tissue levels are unaltered. In the SP pathway, it would appear that NEP is unable to sufficiently degrade the increased amount of SP, which may in part explain the perpetuation of pancreatic inflammation. Removal of pancreatic inflamed tissue, the “pacemaker” of neuroimmune inflammation, resulted in the reduction of the circulating level of SP, supporting the hypothesis of neuroimmune crosstalk in CP. Furthermore the correlation between serum and tissue levels of SP suggest that this neuropeptide might also represent a reliable marker of neurogenic inflammation in CP.
Signal Detection: A New Statistical Method to Predict NASH in Gastric Bypass Patients John M. Morton, Gavitt A. Woodard, Tina Hernandez-Boussard Background: Non-alcoholic steatohepatitis (NASH) is associated with morbid obesity, cardiac risk factor abnormalities, and metabolic syndrome. Currently, there are no adequate preoperative predictive models for NASH identification. We present a new statistical method to address this need. Methods: Signal detection affords the ability to identify patients at risk with both homogeneous outcomes and risk predictors and has been used in cardiac risk assessment. Potential risk factors for NASH were entered into the Signal Detection model by Kraemer et al. All patients underwent laparoscopic gastric bypass surgery with intraoperative liver biopsy at a single academic institution by a single surgeon. Preoperatively, liver function tests, cardiac risk factors, and comorbidities were assessed. We dichotomized liver pathology into NASH vs Steatosis (SS) per Brunt criteria for analysis by T-test or ChiSquare analysis as appropriate. Results: 141 patients successfully underwent laparoscopic Roux-en-Y gastric bypass surgery. Patient demographics were mean age, 45; female, 88%; mean BMI, 49; diabetic, 38%; hypertensive, 62%; and hepatitis or alcohol abuse, 0%. Liver biopsy results were Normal (2%), Steatosis (60%) and NASH (38%). The model identified the following variables in order as most discriminating in identifying patients with NASH: ALT>31, excess weight >109 kg, Lipoprotein A>21 and Hemoglobin A1C >6.9. This model identified this subgroup as having an 81% chance of having a pathologic NASH diagnosis. Conclusion: In this study, ALT, excess weight and hemoglobin A1C were correlated with NASH. This innovative new statistical technique affords a new ability to successfully identify gastric bypass patients with biopsy proven NASH.
948 The Role of ERCC1 RNA Expression in Blood As a Non-Invasive Predictor of Response to Neadjuvant Radio-Chemotherapy in Patients with Locally Advanced Cancer of the Esophagus Jan Brabender, Daniel Vallböhmer, Frederike C. Ling, Andreas C. Hoffmann, Georg Lurje, Elfriede Bollschweiler, Arnulf H. Hölscher, Paul M. Schneider, Ralf Metzger
780 Visceral Sensitivity Is Increased During the Initial Development of Postoperative Ileus in Mice Mario H. Mueller, Mia Karpitschka, Andrej Sibaev, Jörg Glatzle, Bing Xue, Michael S. Kasparek, Martin E. Kreis Introduction: Neurogenic, inflammatory and pharmacological alterations during surgery contribute to the pathophysiology of postoperative ileus (POI). We hypothesized that during the initial hours after surgery, afferent nerve fibers supplying the intestine are sensitized for the pain mediator bradykinin and mechanical stimuli which may contribute to efferent reflex inhibition of intestinal motility. We, therefore, aimed to explore intestinal afferent nerve sensitivity and motility during the early development of POI in mice. Methods: Under enflurane anesthesia, C57BL/6 mice underwent laparotomy followed by sham treatment or standardized small bowel manipulation to induce ileus. Then, after 1h, 3h or 9h, extracellular multi-unit mesenteric afferent nerve recordings were established In Vitro from 2 cm segments of jejunum (each subgroup n=6) continuously superfused with Krebs buffer (32°C, gassed with an O2/CO2 mixture). The segment was cannulated from both ends to monitor luminal pressure and intestinal motility simultaneously. Afferent discharge to luminal distension (080 cmH2O) and bradykinin (1µM) was recorded. Peak discharge frequency and intestinal motor events were analyzed by two-way ANOVA. Results: The mean amplitude of intestinal contractions was 0.8±0.2cmH2O 1 h after induction of POI and 5±0.8 cmH2O in segments taken after 1 h from sham controls (p<0.05). A similar difference was observed for segments harvested at the 3h and 9h time point (both p<0.05). Serosal bradykinin was followed by an increase in afferent discharge to 61±6 impsec-1 after 1h, 217±25 impsec-1 after 3h and 217±6 impsec-1 after 9h in ileus segments increased compared to 46±3 impsec-1 after 1h, 57±10 impsec-1 after 3h and 140±13 impsec-1 after 9h in sham controls (*P<0.05). The afferent response during ileus was augmented at high threshold luminal distension at 80 cmH2O (912±79 impsec-1 after 1h, 933±30 impsec-1 after 3h and 1131±63 impsec-1 after 9h) when compared to sham controls (639±39 impsec-1 after 1h, 714±40 impsec-1 after 3h and 1165±30 impsec-1 after 9h), (P<0.05). Conclusions: Afferent discharge to bradykinin and high pressure luminal distension is augmented in the early stage of postoperative ileus. As high-threshold mechanosensitivity and the algesic mediator bradykinin activate predominantly spinal afferents, spinal sensitization seems to occur at the initial stage of postoperative ileus which may trigger a reflex inhibition of intestinal motility perpetuating postoperative ileus.
949 Strong Prognostic Value of Nodal Microinvolvement in Patients with Carcinoma of the Papilla of Vater Receiving No Adjuvant Chemotherapy Dean Bogoevski, Paulus G. Schurr, Jussuf T. Kaifi, Guell Cataldegirmen, Oliver Mann, Yogesh K. Vashist, Emre F. Yekebas, Jakob R. Izbicki Background: To assess the prognostic significance of nodal microinvolvement in patients with carcinoma of the Papilla of Vater. Methods: From 1993 to 2003 at the University Clinic Hamburg, 777 patients were operated upon pancreatic and periampullary carcinomas. The vast majority of patients were operated upon pancreatic ductal adenocarcinoma (n=566, 73%), followed by carcinoma of the papilla of Vater (n=112, 14%), neuroendocrine carcinoma (n=39, 5%), IPMN (n=33, 4%) and distal bile duct carcinoma (n=27, 3%). Fresh-frozen tissue sections from 169 LN's classified as tumor free by routine histopathology from 57 patients with R0 resected carcinoma of the papilla of Vater who had been spared from adjuvant chemotherapy were immunohistochemically (IHC) examined, using a sensitive IHC assay with the anti-epithelial monoclonal antibody Ber-EP4 for tumor cell detection. With regard to histopathology, 39(63%) of the patients were staged as pT1/pT2, 21(37%) as pT3/pT4, 30(53%) as pN0, while 38(67%) as G1/G2. Results: Of the 169 “tumor free” LN's, 91 LN'S (53.8%) contained Ber-EP4-positive tumor cells. These 91 LN's were from 40(70%) patients. The mean overall survival in patients without nodal microinvolvement of 35.8 months (median-not yet reached) was significantly longer than that in patients with nodal microinvolvement (mean 16.6; median 13) (p=0.019). Multivariate Cox regression analysis for overall survival revealed that grading was the most significant independent prognostic factor (p=0.001), followed by nodal microinvolvement (p=0.013). Conclusions: The influence of occult tumor cell dissemination inLN's of patients with histologically proven carcinoma of the papilla of Vater supports the need for further tumor staging through immunohistochemistry.
781 Tissue and Serum Levels of Substance P Correlate in Patients with Chronic Pancreatitis Giuseppe Mascetta, Fabio Francesco di Mola, Federico Selvaggi, Massimo Falconi, Claudio Bassi, Nathalia Giese, Markus W. Buechler, Helmut M. Friess, Pierluigi Di Sebastiano The pathophysiology of pain in chronic pancreatitis (CP) is still unclear. Recent data suggest a role for neuropeptides such as substance P (SP) and the neuroimmune interaction in the inflammatory process of the pancreas. SP degradation is mediated by the endogenous extracellular metalloenzyme called neutral endopeptidase (NEP). Actually, no data are available regarding the relationship between tissue and serum levels of SP in CP. In this study we aimed to investigate a possible correlation between SP mRNA expression in pancreatic tissue and serum levels of SP in patients undergoing surgical resection for CP and to test the hypothesis that neuroimmune inflammation is a pathogenetic factor in CP. Materials and Methods. SP and NEP mRNA levels were analyzed by quantitative RT-PCR in pancreatic tissue specimens from 30 patients undergoing pancreatic resection for CP and 8 healthy organ donors. In addition, SP serum levels were determined before and after surgery and in 8 healthy individuals (control group) using an ELISA test. Results. Quantitative RT-PCR demonstrated increased SP mRNA expression in CP tissues (P<0.05) compared to controls, while NEP mRNA expression showed no significant changes between CP and healthy controls. The SP preoperative serum levels correlated with SP tissue levels in CP patients. After pancreatic resection, the majority of CP patients exhibited a significantly reduced expression of SP serum levels compared with preoperative levels. Conclusions: The present data show
950 The Prognostic Superiority of Log Odds of Lymph Nodes in Stage III Colon Cancer Jiping Wang, James M. Hassett, Merril T. Dayton, Mahmoud N. Kulaylat Background: Recent literature has shown that lymph node ratio (LNR) and log of odds (LODDS) of positive lymph nodes (LN) can equally predict prognosis in patients with breast cancer. We hypothesize that in patients with stage III colon cancer, LODDS is even superior to LNR. Methods: 24,477 stage III colon cancer cases from SEER are included. Based on
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SSAT Abstracts
Background: Only patients with locally advanced cancer of the esophagus with a major response to neadjuvant radio-chemotherapy do benefit from this treatment. Unfortunately, no non-invasive molecular marker exists that can reliably predict response to neadjuvant therapy in this disease. To improve the treatment of patients with cancer of the esophagus, molecular predictors of response are desperately needed. Aim of this study was to determine the value of ERCC1 RNA-Expression in peripheral blood of patients with cancer of the esophagus as a non-invasive molecular predictor of response to neoadjuvant therapy. Material and methods: A total of 29 patients with locally advanced cancer of the esophagus were included in this study. Blood samples were drawn from each patient prior to neoadjuvant therapy (cis-Platin, 5-FU, 36Gy). Transthoracic en-bloc esophagectomy was performed in all patients following completion of neadjuvant therapy. After extraction of cellular tumorRNA from blood samples, quantitative expression analysis of ERCC1 and the internal reference gene beta-Actin was done by real-time RT-PCR. Histomorphological regression was defined as major response when resected specimen contained <10% of residual vital tumor cells, and minor response with >10% of vital residual tumor cells. Results: Nineteen of 29 (65.5%) patients showed a minor histopathological response and 10(34.5%) showed a majorresponse to neadjuvant therapy. ERCC1 RNA expression in blood of patients was detectable for ERCC1 in 82.8% and 100% for beta-Actin. The median ERCC1 expression was 0.62 (min.: 0.00, max.: 2.48) in minor-responders and 0.24 (min.: 0.00, max.: 0.45) in majorresponders (p=0.004). No significant associations were detected between ERCC1 expression levels and patients clinical variables (histology, tumor stage, gender etc.). Relative ERCC1 expression levels above 0.452 were not associated with major histopathological response (sensitivity: 68.4; specificity: 100%) and 13 of 19 patients with minor response to the delivered neadjuvant therapy could be unequivocally identified. Conclusion: The applied method is technically feasable for the analysis of cellular ERCC1 RNA expression in blood of patients with cancer of the esophagus. Minor-responders to the applied therapy show a significant higher ERCC1 expression level in their blood compared to major-resonders prior to therapy. ERCC1 expression levels in blood appear to be highly specific to predict minorresponse to neoadjuvant radiochemotherapy in patients with esophageal cancer and could be applied to prevent expensive, noneffective, and potentially harmful therapies in a substantial number (45%) of patients.
LNR, patients are categorized into four groups, LNR1 to 4, according to cutoff points 1/14, 0.25 and 0.50 and on LODDS, patient are divided into five groups, LODDS 1 to 5, according to cutoff points -2.2, -1.1, 0 and 1.1. Kaplan-Meier and Cox proportional hazard model were used to evaluate the prognostic effect and estimate the relative risk (RR) and 95% confidence interval (CI). Results: In stage III colon cancer, both LNR and LODDS are in agreement in staging patients except LNR4. When stratify LNR4 into LODDS4 and LODDS5, patients have significant different 5-year survival (33.5% vs. 23.3%, p<0.0001). The observed 5-year survival for stage IIIB patients classified as LODDS1 to LODDS5 is 63.7%, 54.4%, 44.4%, 35.8% and 30.6% respectively (p<0.0001). On the other hand, the observed 5-year survival for patients with stage IIIC diseases who are classified as LODDS2 to LODDS5 is 49.7%, 41.7%, 29.8% and 18.8% respectively (p<0.0001). Univariate analysis shows that LODDS, LNR, age, race, number of negative LN (NNLN) or total number of LN examined (TNLN), tumor grade, size, and number of positive LN are significantly associated with survival. Whereas, in the multivariate Cox model, NNLN or TNLN, and LNR are not independently associated with survival after adjusting for LODDS. Conclusion: Patients with stage IIIB and IIIC colon cancer represent a heterogeneous group of patients with the majority either over-staged or under-staged. Patients with LNR4 also represent a heterogeneous group. In patients with stage III colon cancer, LODDS is a more accurate prognostic method than AJCC N staging, NNLN, and TNLN. Multivariate Cox model
952 VEGF Gene Therapy Improves Anastomotic Healing in the Gastrointestinal Tract: Applications in Esophageal Surgery Kristian Enestvedt, Shelley R. Winn, Brian S. Diggs, Luke Hosack, Barry Uchida, Robert W. O'Rourke, Blair A. Jobe Background: Anastomotic leak related to ischemia is a source of significant morbidity and mortality. The aim of this study was to utilize VEGF gene therapy for the purpose of upregulating angiogenesis, increasing anastomotic strength, and ultimately preventing dehiscence. Methods: An opossum esophagogastrostomy model was employed. The vascular endothelial growth factor (VEGF165) gene was incorporated into a circular recombinant plasmid. The plasmid was complexed with a non-viral synthetic vector, Jet-PEI. Control animals received plasmid devoid of VEGF165 (n=6). The experimental group received VEGF165 plasmid (n=5). After esophagogastrectomy and gastric tubularization, plasmid was injected into the submucosa of the neoesophagus at the anastomotic site. Conduit arteriography was performed before and 10 days after injection. Euthanasia occurred on post-injection day 10 and the anastomosis was removed en bloc. Blood flow was measured with laserDoppler prior to euthanasia. Ex vivo anastomotic bursting pressure was performed. Tissue samples were procured for RNA extraction and Factor VIII staining. Microvessel counts were obtained by 2 blinded observers. VEGF mRNA transcript levels were measured with quantitative RT-PCR using custom primers. Results: There were no deaths in either group. There was one leak in the control group. Experimental animals demonstrated significantly increased bursting pressure and neovascularization compared to controls (Table). In addition, there was a strongly positive correlation between the number of microvessels and bursting pressure (r=0.808, p=0.015, Pearson's). On angiographic examination, treated animals demonstrated more neovascularization compared to controls. RT-PCR demonstrated a 2.1 fold increase in VEGF mRNA tissue transcript levels in treated animals compared to controls (p=0.05, t-test). Discussion: This first description of successful gene therapy in the gastrointestinal tract using VEGF165 transfection demonstrates improved anastomotic healing in a clinically relevant model which may directly translate to human application.
*all numbers are mean values 953 Loss of Heterozygosity Portends Poor Survival of Patients with Resected Periampullary Cancer Jan Franko, Alyssa M. Krasinskas, Marina N. Nikiforova, Yuri E. Nikiforov, Steven J. Hughes, Kenneth K. Lee, David L. Bartlett, Herbert Zeh, Arthur J. Moser
SSAT Abstracts
951 High Expression of Heparanase Is Significantly Associated with Dedifferentiation and Lymph Node Metastasis in Patients with Pancreatic Ductal Adenocarcinomas and Correlated to PDGFA and Via HIF1a to HB-EGF and bFGF Andreas C. Hoffmann, Ryutaro Mori, Daniel Vallbohmer, Jan Brabender, Uta Drebber, Stephan E. Baldus, Mizutomo Azuma, Ralf Metzger, Christina Hoffmann, Arnulf H. Hölscher, Kathleen D. Danenberg, Klaus L. Prenzel, Peter V. Danenberg
Background: Traditional AJCC staging system for periampullary adenocarcinoma has been well validated but improvements in prognostic accuracy are still needed. We hypothesized that molecular and genetic methods may predict biological behavior and postoperative survival independently of stage. Methods: Pancreatic ductal and ampullary carcinomas treated by pancreaticoduodenectomy in 2006 (n=50) were subjected to laser capture microdissection followed by loss of heterozygosity (LOH) analysis at 14 different chromosomal loci including 5q (APC), 6q (thrombospondin), 9p (p16), 10q (Pten), 12q (MDM2), 17p (p53), and 18q (DDC/DPC4). Mutations at k-ras exon 1 (codons 12 and 13) were assessed by PCR. The relationship between genetic alterations and clinical outcome was studied. Results: Negative resection margins were achieved in 43 (86%) cases. AJCC stage distribution was: Ia/b (3), IIa (16), IIb (29), and III (2). K-ras mutations were observed in 31 cases (62%). Allelic losses were identified in 26 (52%) with a median fractional allelic loss score of 18% (range 7-64%). There was no concordance between LOH and k-ras mutations (McNemar p=0.405). Survival was significantly shorter in patients with allelic losses (17.5 versus 21.2 months; p=0.039). Both higher AJCC stage (HR=1.29, p=0.018) and presence of LOH (HR=6.60, p=0.027) were identified as independent predictors of shorter survival in a Cox regression model. Increased fractional allelic loss portended worsened survival (HR=1.043 per percent loss, p=0.034), whereas age and k-ras mutations did not. Conclusion: Loss of heterozygosity predicts survival independently from stage in resected periampullary cancer. Allelic losses indicate more aggressive tumor biology and may improve risk stratification in future clinical trials.
Background: Pancreatic cancer still has the worst prognosis of all cancers with a 5-year survival rate of 5%. Due to late symptoms of pancreatic cancer and therefore often late diagnosis, only 10-20% of the patients are eligible for complete resection with curative intention, making it necessary to find markers or gene-sets which would further classify patients into different risk categories and thus allow more individually adapted multimodality treatment regimens. Some of the most promising genes described also in other entities are linked to angiogenesis. Especially HPSE has recently been discussed as a key factor in pancreatic cancer. Materials and Methods: Paraffin-embedded tissue samples were obtained from 41 patients with pancreatic adenocarcinoma with a median age of 65 years (range 34 - 85 years) at time of operation who were scheduled for primary surgical resection. After laser capture microdissection direct quantitative real-time reverse transcriptase PCR (RTPCR, TaqMan™) assays were performed in triplicates to determine HPSE, HIF1a, PDGFA, HB-EGF and bFGF gene expression levels. Gene expression was normalized with betaActin. Decision tree analysis and the maximal chi-square method were adapted to determine which gene expression value best segregated patients into lymph node negative and positive, and high and low dedifferentiation subgroups. Results: HPSE was significantly correlated to PDGFA (p=0.04) and to HIF1a (p=0.04). The correlation of HIF1a to bFGF and HBEGF expression was significant (p = 0.04, p = 0.02). We put all clinical, histopathological parameters and the used genes as independent variables in a stepwise multiple linear regression model with lymph node metastasis as the dependent variable. The overall model fit had a significance level of p = 0.029 (<0.05) with HPSE as the only significant predictor of lymph node metastasis, though pT was almost included. Using a stepwise multiple regression analysis to evaluate the most influential of the accessible factors on the dedifferentiation of the tumor the overall model fit was significant at a level of p = 0.003 (<0.05). The most significant independent factor was HPSE for predicting the grade of dedifferentiation. Conclusions: Considering the fact that Heparanase seems to be a highly significant independent variable for lymph-node metastasis (p = 0.029; <0.05) as well as for dedifferentiation (p = 0.003; <0.05) we assume that HPSE plays a crucial role for the aggressiveness of pancreatic cancer. Though these results were obtained on a relatively small number of patients, larger studies including patients treated with actual chemotherapeutics seem to be warranted.
Survival of patients with resected periampullary cancer stratified by LOH status.
SSAT Abstracts
A-856