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Dive into the research topics where Emre F. Yekebas is active.

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Featured researches published by Emre F. Yekebas.


Annals of Surgery | 2008

En bloc vascular resection for locally advanced pancreatic malignancies infiltrating major blood vessels: perioperative outcome and long-term survival in 136 patients.

Emre F. Yekebas; Dean Bogoevski; Guellue Cataldegirmen; Christina Kunze; Andreas Marx; Yogesh K. Vashist; Paulus G. Schurr; Lena Liebl; Sabrina Thieltges; Karim A. Gawad; Claus Schneider; Jakob R. Izbicki

Background:To assess in-hospital complication rates and survival duration after en bloc vascular resection (VR) for infiltration of pancreatic malignancies in major vessels. Methods:Between 1994 and 2005, 585 patients underwent potentially curative pancreatic resection without adjuvant chemotherapy. Four hundred forty-nine patients (77%) underwent standard oncologic resection (VR−), whereas 136 (23%) received VR (VR+). For calculation of in-hospital morbidity and mortality rates, all 136 patients who underwent VR were considered. In contrast, for survival analysis, only pancreatic adenocarcinoma patients (n = 100) were included. Results:One hundred twenty-eight VR+ patients underwent portal or superior mesenteric vein resection and 13 hepatic artery (HA) or superior mesenteric artery (SMA) resection. In 5 patients, synchronous VR addressing both the mesenterico-portal axis and either the HA or SMA was performed. In-hospital morbidity and mortality rates of VR− patients (39.7%/4.0%) nearly equaled that of VR+ patients (40.3%/3.7%). From the 100 patients with pancreatic adenocarcinoma, histopathology confirmed “true” vascular invasion in 77 patients. Twenty-three patients had peritumoral inflammation, mimicking tumor invasion. Median survival was 15 months (11.2–18.8) in patients with histopathologic proven vascular invasion and 16 months (14.0–17.9) in those without (P = 0.86). Two-year survival probabilities were 36% (without) versus 34% (with vascular invasion; P = 0.9). Among VR+ patients with histopathologically evidenced vascular invasion, 19 survived longer than 30 months, and 6 were still alive 5 years after surgery. Multivariate modeling identified nodal involvement (N1) and poor grading (G3) as the only predictors of decreased survival. Evidence of vascular invasion had no adverse impact on survival. Conclusion:Postoperative morbidity and mortality rates after en bloc VR are comparable with “standard” pancreatectomy procedures. Median survival of 15 months in patients with vascular invasion is superior to that of patients who undergo palliative therapy and nearly equals that of patients who are not in need for VR.


Annals of Surgery | 2007

Postpancreatectomy Hemorrhage: Diagnosis and Treatment: An Analysis in 1669 Consecutive Pancreatic Resections

Emre F. Yekebas; Lars Wolfram; Guellue Cataldegirmen; Christian R. Habermann; Dean Bogoevski; Alexandra M. Koenig; Jussuf T. Kaifi; Paulus G. Schurr; Michael Bubenheim; Claus Nolte-Ernsting; Gerhard Adam; Jakob R. Izbicki

Background:To analyze clinical courses and outcome of postpancreatectomy hemorrhage (PPH) after major pancreatic surgery. Summary Background Data:Although PPH is the most life-threatening complication following pancreatic surgery, standardized rules for its management do not exist. Methods:Between 1992 and 2006, 1524 patients operated on for pancreatic diseases were included in a prospective database. A risk stratification of PPH according to the following parameters was performed: severity of PPH classified as mild (drop of hemoglobin concentration <3 g/dL) or severe (>3 g/dL), time of PPH occurrence (early, first to fifth postoperative day; late, after sixth day), coincident pancreatic fistula, intraluminal or extraluminal bleeding manifestation, and presence of “complex” vascular pathologies (erosions, pseudoaneurysms). Success rates of interventional endoscopy and angiography in preventing relaparotomy were analyzed as well as PPH-related overall outcome. Results:Prevalence of PPH was 5.7% (n = 87) distributed almost equally among patients suffering from malignancies, borderline tumors, and focal pancreatitis (n = 47) and from chronic pancreatitis (n = 40). PPH-related overall mortality of 16% (n = 14) was closely associated with 1) the occurrence of pancreatic fistula (13 of 14); 2) vascular pathologies, ie, erosions and pseudoaneurysms (12 of 14); 3) delayed PPH occurrence (14 of 14); and 4) underlying disease with lethal PPH found only in patients with soft texture of the pancreatic remnant, while no patient with chronic pancreatitis died. Conversely, primary severity of PPH (mild vs. severe) and the kind of index operation (Whipple resection, pylorus-preserving partial pancreaticoduodenectomy, organ-preserving procedures) had no influence on outcome of PPH. Endoscopy was successful in 3 from 15 patients (20%), who had intraluminal PPH within the first or second postoperative day. “True,” early extraluminal PPH had uniformly to be treated by relaparotomy. Seventeen patients had “false,” early extraluminal PPH due to primarily intraluminal bleeding site from the pancreaticoenteric anastomosis with secondary disruption of the anastomosis. From 43 patients subjected to angiography, 25 underwent interventional coiling with a success rate of 80% (n = 20). Overall, relaparotomy was performed in 60 patients among whom 33 underwent surgery as first-line treatment, while 27 were relaparotomied as rescue treatment after failure of interventional endoscopy or radiology. Conclusion:Prognosis of PPH depends mainly on the presence of preceding pancreatic fistula. Decision making as to the indication for nonsurgical interventions should consider time of onset, presence of pancreatic fistula, vascular pathologies, and the underlying disease.


Human Pathology | 2010

HER-2 amplification is highly homogenous in gastric cancer

Andreas Marx; Lars Tharun; Johanna Muth; Ana-Maria Dancau; Ronald Simon; Emre F. Yekebas; Jussuf T. Kaifi; Martina Mirlacher; Tim H. Brümmendorf; Carsten Bokemeyer; Jakob R. Izbicki; Guido Sauter

Her-2 is the molecular target for antibody-based treatment of breast cancer (trastuzumab). The potential benefit of anti-Her-2 therapy is currently investigated in several other HER-2-amplified cancers including gastric cancer. Although HER-2 amplification occurs in more than 10% of gastric cancers, potential heterogeneity of HER-2 amplification and overexpression could represent a major drawback for anti-Her-2 therapy. To address the potential applicability of trastuzumab in gastric cancer, tissue microarray sections of 166 gastric adenocarcinomas and 69 lymph node metastases were analyzed for Her-2 overexpression and amplification using Food and Drug Administration-approved reagents for immunohistochemistry and fluorescence in situ hybridization. HER-2 amplification was seen in 27 (16%) of 166 gastric adenocarcinomas. Amplification was typically high level with more than 20 HER-2 copies per tumor cell and a HER-2/centromere 17 ratio >3. Amplification was associated with intestinal tumor phenotype but unrelated to survival, grading, pT, pN, or pM. Identical HER-2 status was found in primary tumor and their matched lymph node metastases. Moreover, HER-2 and Topoisomerase IIalpha coamplification analysis of 3 to 16 large sections from 8 Her-2-positive gastric cancers did not reveal any heterogeneity of the amplicon site. The high level of HER-2 amplification in combination with the homogeneity of its expression in primary and metastatic tumors argues for a possible therapeutic utility of trastuzumab in HER-2-amplified gastric adenocarcinomas.


Annals of Surgery | 2005

Long-term Follow-up of a Randomized Trial Comparing the Beger and Frey Procedures for Patients Suffering From Chronic Pancreatitis

Tim Strate; Zohre Taherpour; Christian Bloechle; Oliver Mann; Jens P. Bruhn; Claus Schneider; Thomas Kuechler; Emre F. Yekebas; Jakob R. Izbicki

Objective:To report on the long-term follow-up of a randomized clinical trial comparing pancreatic head resection according to Beger and limited pancreatic head excision combined with longitudinal pancreatico-jejunostomy according to Frey for surgical treatment of chronic pancreatitis. Summary Background Data:Resection and drainage are the 2 basic surgical principles in surgical treatment of chronic pancreatitis. They are combined to various degrees by the classic duodenum preserving pancreatic head resection (Beger) and limited pancreatic head excision combined with longitudinal pancreatico-jejunostomy (Frey). These procedures have been evaluated in a randomized controlled trial by our group. Long-term follow up has not been reported so far. Methods:Seventy-four patients suffering from chronic pancreatitis were initially allocated to DPHR (n = 38) or LE (n = 36). This postoperative follow-up included the following parameters: mortality, quality of life (QL), pain (validated pain score), and exocrine and endocrine function. Results:Median follow-up was 104 months (72-144). Seven patients were not available for follow-up (Beger = 4; Frey = 3). There was no significant difference in late mortality (31% [8/26] versus 32% [8/25]). No significant differences were found regarding QL (global QL 66.7 [0–100] versus 58.35 [0–100]), pain score (11.25 [0–75] versus 11.25 [0–99.75]), exocrine (88% versus 78%) or endocrine insufficiency (56% versus 60%). Conclusions:After almost 9 years’ long-term follow-up, there was no difference regarding mortality, quality of life, pain, or exocrine or endocrine insufficiency within the 2 groups. The decision which procedure to choose should be based on the surgeons experience.


Modern Pathology | 2007

Frequent homogeneous HER-2 amplification in primary and metastatic adenocarcinoma of the esophagus

Uta Reichelt; Peer Duesedau; Maria C. Tsourlakis; Alexander Quaas; Björn C Link; Paulus G. Schurr; Jussuf T. Kaifi; Stephanie J. Gros; Emre F. Yekebas; Andreas Marx; Ronald Simon; Jakob R. Izbicki; Guido Sauter

HER-2 is the target for antibody based treatment of breast cancer (Herceptin®). In order to evaluate the potential role of such a treatment in esophageal cancers, HER-2 amplification and overexpression was investigated in primary and metastatic cancers of the esophagus. A tissue microarray was constructed from 255 primary esophageal cancers (110 adenocarcinomas and 145 squamous cell carcinomas), 89 nodal and 33 distant metastases. Slides were analyzed by immunohistochemistry (HercepTest™; DAKO) and fluorescence in situ hybridization (FISH; PathVysion™; Vysis-Abbott) for HER-2 amplification and overexpression. Amplification was seen in 16/110 (15%) adenocarcinomas and in 7/145 (5%) squamous cell carcinomas. There was a strong association between HER-2 amplification and overexpression, especially in adenocarcinomas (P<0.0001, log rank). There was a 100% concordance of the HER-2 results in primary tumor and corresponding metastases in 84 analyzed pairs. Amplification was typically high-level with more than 10–15 HER-2 copies per tumor cell. Amplification was unrelated to survival, grading, pT, pN, pM or UICC stage. We conclude that esophageal adenocarcinomas belong to those cancer types with relevant frequency high-level HER-2 gene amplification clinical trials or individual case studies investigating the response of metastatic HER-2-positive esophageal cancers to Herceptin® should be undertaken. The strong concordance of the HER-2 status in primary and metastatic cancers argues for a possible response of metastases from patients with HER-2-positive primary tumors to Herceptin®.


Annals of Surgery | 2007

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

Paulus G. Schurr; Tim Strate; Kim Rese; Jussuf T. Kaifi; Uta Reichelt; Susanne Petri; Helge Kleinhans; Emre F. Yekebas; Jakob R. Izbicki

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.


Gastroenterology | 2008

Resection vs drainage in treatment of chronic pancreatitis: long-term results of a randomized trial.

Tim Strate; Kai Bachmann; Philipp Busch; Oliver Mann; Claus Schneider; Jens P. Bruhn; Emre F. Yekebas; Thomas Kuechler; Christian Bloechle; Jakob R. Izbicki

BACKGROUND & AIMS Tailored organ-sparing procedures have been shown to alleviate pain and are potentially superior in terms of preservation of endocrine and exocrine function as compared with standard resection (Whipple) for chronic pancreatitis with inflammatory pancreatic head tumor. Long-term results comparing these 2 procedures have not been published so far. The aim of this study was to report on long-term results of a randomized trial comparing a classical resective procedure (pylorus-preserving Whipple) with an extended drainage procedure (Frey) for chronic pancreatitis. METHODS All patients who participated in a previously published randomized trial on the perioperative course comparing both procedures were contacted with a standardized, validated, quality of life and pain questionnaire. Additionally, patients were seen in the outpatient clinic to assess endocrine and exocrine pancreatic function by an oral glucose tolerance test and fecal chymotrypsin test. RESULTS There were no differences between both groups regarding quality of life, pain control, or other somatic parameters after a median of 7 years postoperatively. Correlations among continuous alcohol consumption, endocrine or exocrine pancreatic function, and pain were not found. CONCLUSIONS Both procedures provide adequate pain relief and quality of life after long-term follow-up with no differences regarding exocrine and endocrine function. However, short-term results favor the organ-sparing procedure.


Critical Care Medicine | 2001

Attenuation of sepsis-related immunoparalysis by continuous veno-venous hemofiltration in experimental porcine pancreatitis.

Emre F. Yekebas; Claus F. Eisenberger; Henning Ohnesorge; Armin Saalmüller; Holger-Andreas Elsner; Madelaine Engelhardt; Andrea Gillesen; Tim Strate; Christoph Busch; Wolfram T. Knoefel; Christian Bloechle; Jakob R. Izbicki

ObjectivesIn light of evidence suggesting that hemofiltration favorably influences septic diseases by removing sepsis mediators, the impact of different modalities of continuous veno-venous hemofiltration (CVVH) on outcome and immunologic derangements in porcine pancreatogenic sepsis was evaluated. DesignRandomized, controlled intervention trial. SubjectsForty-eight minipigs of either sex. InterventionsPancreatitis was induced by intraductal injection of sodium taurocholate (4%, 1 mL/kg body weight [BW]) and enterokinase (2 U/kg BW). Animals were allocated either to untreated controls—group 1—or to one of three treatment groups—group 2: low-volume CVVH (20 mL/kg BW), no change of hemofilters; group 3: low-volume CVVH, filters changed every 12 hrs; and group 4: high-volume CVVH (100 mL/kg BW), filters changed every 12 hrs. Survival represented the major parameter of the study. Serum cytokine levels, sepsis-related down-regulation of major histocompatibility complex II and CD14 expression on leukocytes, bacterial translocation, and endotoxemia were further parameters evaluated in the study. Measurements and Main Results High-volume CVVH combined with periodic filter change was significantly superior compared with less intensive treatment modalities (low-volume CVVH, no filter change) in sepsis protection. Long-term survival (>60 hrs) was found in 67% of group 4 and 33% of group 3 animals (p < .05), whereas in controls and group 2 no animal survived. CVVH ameliorated the initial serum tumor necrosis factor-&agr; response and prevented sepsis-induced in vitro endotoxin hyporesponsiveness. Down-regulation of major histocompatibility complex II and CD14 expression on monocytes was significantly improved by CVVH. Improved oxidative burst and phagocytosis capacity in polymorphonuclear leukocytes suggested that leukocyte function was stabilized by CVVH. Also, CVVH significantly reduced bacterial translocation and endotoxemia. ConclusionsHemofiltration reversed sepsis-induced immunoparalysis in a porcine model of bile acid–induced pancreatitis. Implications for human pancreatitis must be validated in prospective, clinical protocols.


The Prostate | 2011

High level PSMA expression is associated with early PSA recurrence in surgically treated prostate cancer.

Sarah Minner; Corinna Wittmer; Markus Graefen; Georg Salomon; Thomas Steuber; Alexander Haese; Hartwig Huland; Carsten Bokemeyer; Emre F. Yekebas; Judith Dierlamm; Stefan Balabanov; Ergin Kilic; Waldemar Wilczak; Ronald Simon; Guido Sauter; Thorsten Schlomm

Prostate specific membrane antigen (PSMA) is a suggested target for antibody‐based therapy of prostate cancer potentially involved in the regulation of cell migration. This study was undertaken, to gain more insight on the role of PSMA in early prostate cancer and its distribution in various normal tissues.


Clinical Cancer Research | 2010

Chromosome 8p deletions and 8q gains are associated with tumor progression and poor prognosis in prostate cancer.

Alexander T. El Gammal; Michael Brüchmann; Jozef Zustin; Hendrik Isbarn; Olaf Hellwinkel; Jens Köllermann; Guido Sauter; Ronald Simon; Waldemar Wilczak; Jörg Schwarz; Carsten Bokemeyer; Tim H. Brümmendorf; Jakob R. Izbicki; Emre F. Yekebas; Margit Fisch; Hartwig Huland; Markus Graefen; Thorsten Schlomm

Purpose: Deletions of 8p and gains of 8q belong to the most frequent cytogenetic alterations in prostate cancer. The target genes of these alterations and their biological significance are unknown. Experimental Design: To determine the relationship between chromosome 8 changes, and prostate cancer phenotype and prognosis, a set of 1.954 fully annotated prostate cancers were analyzed in a tissue microarray format by fluorescence in situ hybridization. Results: Both 8p deletions and 8q gains increased in number during different stages of prostate cancer progression. 8p deletions/8q gains were found in 26.1%/4.8% of 1,239 pT2 cancers, 38.5%/9.8% of 379 pT3a cancers, 43.5%/8.9% of 237 pT3b cancers, 40.7%/14.8% of 27 pT4 cancers, 39.1%/34.8% of 23 nodal metastases, 51.9%/33.3% of 27 bone metastases, and 45.5%/59.9% of 22 hormone refractory cancers (P < 0.0001 each). Both 8p deletions and 8q gains were also significantly associated with high Gleason grade and with each other (P < 0.0001 each). In primary tumors, 8p deletions were seen in only 27.3% of 1,882 cancers without 8q gain but in 57.4% of 122 tumors with 8q gain (P < 0.0001). Among cancers treated with radical prostatectomy, 8p deletions (P = 0.003) and 8q gains (P = 0.02) were associated with biochemical tumor recurrence. However, multivariate analysis (including prostate-specific antigen, pT/pN stage, Gleason score, and surgical margin status) did not reveal any statistically independent effect of 8p or 8q alterations on biochemical tumor recurrence. Conclusions: 8p deletions and 8q gains are relatively rare in early stage prostate cancer but often develop during tumor progression. The prognostic effect does not seem to be strong enough to warrant clinical application. Clin Cancer Res; 16(1); 56–64

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Jussuf T. Kaifi

Pennsylvania State University

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