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Dive into the research topics where Yogesh K. Vashist is active.

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Featured researches published by Yogesh K. Vashist.


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.


Surgery | 2014

Borderline resectable pancreatic cancer: A consensus statement by the International Study Group of Pancreatic Surgery (ISGPS)

Maximilian Bockhorn; Faik G. Uzunoglu; Mustapha Adham; Clem W. Imrie; Miroslav Milicevic; Aken A. Sandberg; Horacio J. Asbun; Claudio Bassi; Markus W. Büchler; Richard Charnley; Kevin C. Conlon; Laureano Fernández Cruz; Christos Dervenis; Abe Fingerhutt; Helmut Friess; Dirk J. Gouma; Werner Hartwig; Keith D. Lillemoe; Marco Montorsi; John P. Neoptolemos; Shailesh V. Shrikhande; Kyoichi Takaori; William Traverso; Yogesh K. Vashist; Charles M. Vollmer; Charles J. Yeo; Jakob R. Izbicki

BACKGROUND This position statement was developed to expedite a consensus on definition and treatment for borderline resectable pancreatic ductal adenocarcinoma (BRPC) that would have worldwide acceptability. METHODS An international panel of pancreatic surgeons from well-established, high-volume centers collaborated on a literature review and development of consensus on issues related to borderline resectable pancreatic cancer. RESULTS The International Study Group of Pancreatic Surgery (ISGPS) supports the National Comprehensive Cancer Network criteria for the definition of BRPC. Current evidence supports operative exploration and resection in the case of involvement of the mesentericoportal venous axis; in addition, a new classification of extrahepatic mesentericoportal venous resections is proposed by the ISGPS. Suspicion of arterial involvement should lead to exploration to confirm the imaging-based findings. Formal arterial resections are not recommended; however, in exceptional circumstances, individual therapeutic approaches may be evaluated under experimental protocols. The ISGPS endorses the recommendations for specimen examination and the definition of an R1 resection (tumor within 1 mm from the margin) used by the British Royal College of Pathologists. Standard preoperative diagnostics for BRPC may include: (1) serum levels of CA19-9, because CA19-9 levels predict survival in large retrospective series; and also (2) the modified Glasgow Prognostic Score and the neutrophil/lymphocyte ratio because of the prognostic relevance of the systemic inflammatory response. Various regimens of neoadjuvant therapy are recommended only in the setting of prospective trials at high-volume centers. CONCLUSION Current evidence justifies portomesenteric venous resection in patients with BRPC. Basic definitions were identified, that are currently lacking but that are needed to obtain further evidence and improvement for this important patient subgroup. A consensus for each topic is given.


Annals of Surgery | 2016

Pancreatogastrostomy Versus Pancreatojejunostomy for RECOnstruction After PANCreatoduodenectomy (RECOPANC, DRKS 00000767): Perioperative and Long-term Results of a Multicenter Randomized Controlled Trial.

Tobias Keck; Ulrich F. Wellner; M. Bahra; F. Klein; Olivia Sick; Marco Niedergethmann; T. J. Wilhelm; Stefan Farkas; T. Börner; Christiane J. Bruns; A. Kleespies; Joerg Kleeff; A. L. Mihaljevic; Waldemar Uhl; A. Chromik; V. Fendrich; K. Heeger; W. Padberg; A. Hecker; U. P. Neumann; K. Junge; J. C. Kalff; T. R. Glowka; Jens Werner; P. Knebel; P. Piso; M. Mayr; Jakob R. Izbicki; Yogesh K. Vashist; Peter Bronsert

Objectives:To assess pancreatic fistula rate and secondary endpoints after pancreatogastrostomy (PG) versus pancreatojejunostomy (PJ) for reconstruction in pancreatoduodenectomy in the setting of a multicenter randomized controlled trial. Background:PJ and PG are established methods for reconstruction in pancreatoduodenectomy. Recent prospective trials suggest superiority of the PG regarding perioperative complications. Methods:A multicenter prospective randomized controlled trial comparing PG with PJ was conducted involving 14 German high-volume academic centers for pancreatic surgery. The primary endpoint was clinically relevant postoperative pancreatic fistula. Secondary endpoints comprised perioperative outcome and pancreatic function and quality of life measured at 6 and 12 months of follow-up. Results:From May 2011 to December 2012, 440 patients were randomized, and 320 were included in the intention-to-treat analysis. There was no significant difference in the rate of grade B/C fistula after PG versus PJ (20% vs 22%, P = 0.617). The overall incidence of grade B/C fistula was 21%, and the in-hospital mortality was 6%. Multivariate analysis of the primary endpoint disclosed soft pancreatic texture (odds ratio: 2.1, P = 0.016) as the only independent risk factor. Compared with PJ, PG was associated with an increased rate of grade A/B bleeding events, perioperative stroke, less enzyme supplementation at 6 months, and improved results in some quality of life parameters. Conclusions:The rate of grade B/C fistula after PG versus PJ was not different. There were more postoperative bleeding events with PG. Perioperative morbidity and mortality of pancreatoduodenectomy seem to be underestimated, even in the high-volume center setting.


Cancer Research | 2011

Notch signaling activated by replication stress-induced expression of Midkine drives Epithelial-Mesenchymal Transition and Chemoresistance in Pancreatic Cancer

Cenap Güngör; Hilke Zander; Katharina E. Effenberger; Yogesh K. Vashist; Tatyana Kalinina; Jakob R. Izbicki; Emre F. Yekebas; Maximilian Bockhorn

The incidence of pancreatic ductal adenocarcinoma (PDAC) nearly equals its mortality rate, partly because most PDACs are intrinsically chemoresistant and thus largely untreatable. It was found recently that chemoresistant PDAC cells overexpress the Notch-2 receptor and have undergone epithelial-mesenchymal transition (EMT). In this study, we show that these two phenotypes are interrelated by expression of Midkine (MK), a heparin-binding growth factor that is widely overexpressed in chemoresistant PDAC. Gemcitabine, the front-line chemotherapy used in PDAC treatment, induced MK expression in a dose-dependent manner, and its RNAi-mediated depletion was associated with sensitization to gemcitabine treatment. We identified an interaction between the Notch-2 receptor and MK in PDAC cells. MK-Notch-2 interaction activated Notch signaling, induced EMT, upregulated NF-κB, and increased chemoresistance. Taken together, our findings define an important pathway of chemoresistance in PDAC and suggest novel strategies for its clinical attack.


Nature Genetics | 2015

Common variation at 2p13.3, 3q29, 7p13 and 17q25.1 associated with susceptibility to pancreatic cancer.

Erica J. Childs; Evelina Mocci; Daniele Campa; Paige M. Bracci; Steven Gallinger; Michael Goggins; Donghui Li; Rachel E. Neale; Sara H. Olson; Ghislaine Scelo; Laufey Amundadottir; William R. Bamlet; Maarten F. Bijlsma; Amanda Blackford; Michael Borges; Paul Brennan; Hermann Brenner; H. Bas Bueno-de-Mesquita; Federico Canzian; Gabriele Capurso; Giulia Martina Cavestro; Kari G. Chaffee; Stephen J. Chanock; Sean P. Cleary; Michelle Cotterchio; Lenka Foretova; Charles S. Fuchs; Niccola Funel; Maria Gazouli; Manal Hassan

Pancreatic cancer is the fourth leading cause of cancer death in the developed world. Both inherited high-penetrance mutations in BRCA2 (ref. 2), ATM, PALB2 (ref. 4), BRCA1 (ref. 5), STK11 (ref. 6), CDKN2A and mismatch-repair genes and low-penetrance loci are associated with increased risk. To identify new risk loci, we performed a genome-wide association study on 9,925 pancreatic cancer cases and 11,569 controls, including 4,164 newly genotyped cases and 3,792 controls in 9 studies from North America, Central Europe and Australia. We identified three newly associated regions: 17q25.1 (LINC00673, rs11655237, odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.19–1.34, P = 1.42 × 10−14), 7p13 (SUGCT, rs17688601, OR = 0.88, 95% CI = 0.84–0.92, P = 1.41 × 10−8) and 3q29 (TP63, rs9854771, OR = 0.89, 95% CI = 0.85–0.93, P = 2.35 × 10−8). We detected significant association at 2p13.3 (ETAA1, rs1486134, OR = 1.14, 95% CI = 1.09–1.19, P = 3.36 × 10−9), a region with previous suggestive evidence in Han Chinese. We replicated previously reported associations at 9q34.2 (ABO), 13q22.1 (KLF5), 5p15.33 (TERT and CLPTM1), 13q12.2 (PDX1), 1q32.1 (NR5A2), 7q32.3 (LINC-PINT), 16q23.1 (BCAR1) and 22q12.1 (ZNRF3). Our study identifies new loci associated with pancreatic cancer risk.


Journal of Hepatology | 2002

The induction of the immediate-early-genes Egr-1, PAI-1 and PRL-1 during liver regeneration in surgical models is related to increased portal flow

Lars Mueller; Dieter C. Broering; Jannine Meyer; Yogesh K. Vashist; Juliane Goettsche; Christian Wilms; Xavier Rogiers

BACKGROUND The environmental triggers which control liver regeneration following partial hepatectomy (PH) are not clear. With respect to haemodynamic changes, the model of rat portal branch ligation (PBL) provides the unique opportunity to discriminate transcriptional events, which selectively result from increased portal flow. AIMS The potential role of portal over-flow on early expression of early growth response gene-1 (Egr-1), type-1 plasminogen activator inhibitor (PAI-1) and phosphatase of regenerating liver-1 (PRL-1) was analysed by a comparative experimental study using PBL and PH. METHODS Operative procedures were carried out in male Wistar rats. Growth kinetics were measured by liver weight indices. S-phase-specific mRNA-levels of H2B-histone protein (H2B), as well as expression analysis of Egr-1, PAI-1 and PRL-1 were examined by Northern blot experiments. RESULTS Growth patterns did not differ significantly between PBL and PH, whereas peak H2B expression occurred earlier after PH. Egr-1 and PAI-1 were specifically induced during the first few hours in the hyper-perfused lobes following PBL and PH. PRL-1-expression selectively peaked 3h after PH and PBL in the hyper-perfused lobes. CONCLUSIONS Increased portal flow after PBL and PH was associated with induction of Egr-1, PAI-1 and PRL-1. Thus, haemodynamic changes affect the molecular immediate-early response during liver regeneration.


Annals of Surgery | 2013

Is the Whipple procedure harmful for long-term outcome in treatment of chronic pancreatitis? 15-years follow-up comparing the outcome after pylorus-preserving pancreatoduodenectomy and Frey procedure in chronic pancreatitis.

Bachmann K; Tomkoetter L; Asad Kutup; Erbes J; Yogesh K. Vashist; Oliver Mann; Maximilian Bockhorn; Izbicki

Objective:The aim of this study was to report on 15-year long-term results of a randomized controlled trial comparing extended drainage procedure (Frey) and classical resectional procedure [pylorus-preserving pancreatoduodenectomy (PD)] in patients with chronic pancreatitis. Background:Chronic pancreatitis is a common inflammatory disease with a prevalence of 10 to 30 cases per 100,000 inhabitants. It is characterized by the progressive conversion of pancreatic parenchyma to fibrous tissue. Different surgical procedures are used in treatment of persistent pain. Methods:Sixty-four patients suffering from chronic pancreatitis with inflammatory mass in the pancreatic head were randomly assigned in 2 treatment groups (PD, n = 32) and (Frey, n = 32). The perioperative course of the randomized controlled trial and the 7 years follow-up have been previously published. All participating patients were contacted with a standardized, validated questionnaire (EORTC QLQ C30) to evaluate the long-term survival, quality-of-life pain, and exocrine and endocrine function. Results:In the 15-year long-term follow-up, the pain control was good and comparable between both groups, but the quality of life was better after Frey procedure in regard of the physical status [PD: 100 (0–100) vs PD: 60 (0–100) (P = 0.011)]. No significant differences in terms of the Pain Score were detected between both groups [PD: 7 (0–100) vs Frey 4 (0–100) P = 0.258]. Seven patients after Frey OP and 6 patients after PD were free of pain. Analyzing the postoperative overall survival, a higher long-term mortality was found after PD (53%) than that found after Frey procedure (30%) resulting in a longer mean survival (14.5 ± 0.8 vs 11.3 ± 0.8 years; P = 0.037). No correlation between endocrine or exocrine pancreatic function and pain was found, whereas continuous alcohol consumption was associated with poorer outcome regarding quality of life (P < 0.001) and pain score (P < 0.001). Conclusions:PD and Frey procedure provide good and permanent pain relief and improvement of the quality of life in long-term follow-up. In addition, a longer survival was found after the organ sparing resection. Together with better short-term results, the organ-sparing procedure seems to be favorable in treatment of chronic pancreatitis.


Annals of Surgery | 2012

Options and limitations in applying the fistula classification by the International Study Group for Pancreatic Fistula.

Gebauer F; Kloth K; Tachezy M; Yogesh K. Vashist; Guellue Cataldegirmen; Izbicki; Maximilian Bockhorn

Background: Because of its retrospective character, the classification system of the International Study Group of Pancreatic Fistula (ISGPF) lacks prognostic capacity regarding fistula-related complications. This study aimed to evaluate the options and limitations of the ISGPF classification system and to identify risk factors with respect to clinical decision making. Methods: Between 1992 and 2009, 1966 patients underwent surgery of the pancreas. All patient data were entered into a prospective clinical data management system. Results: After surgery, 276 patients (14%) developed postoperative pancreatic fistula (POPF). ISGPF type A fistula was seen in 69 patients (25%), type B in 110 (39.9%), and type C in 97 (34.1%). Solely due to their death, 16 patients had to be classified as type C fistula, even though they suffered only type A or B. Compared to genuine C fistulas, we were not able to detect any significant predictors, which may allow to distinguish the development in their further clinical course. The level of drainage amylase is of no use, whereas univariate analysis identified underlying disease, type of operation, and high levels of serum amylase or bilirubin on the day of onset of POPF to be prognostic parameters for reoperation. Multivariate analysis found elevated serum C-reactive protein to be an independent factor for increased in-hospital mortality. Conclusions: The ISGPF classification system has its limitations in clinical decision making, because it does not adequately describe a large subgroup of patients. To improve clinical decision making about management of patients, it is crucial that the ISGPF classification system is merged with newer clinical data.


Surgery | 2014

Prognostic significance of Zinc finger E-box binding homeobox 1 (ZEB1) expression in cancer cells and cancer-associated fibroblasts in pancreatic head cancer

Peter Bronsert; Ilona Kohler; Sylvia Timme; Selina Kiefer; Martin Werner; Oliver Schilling; Yogesh K. Vashist; Frank Makowiec; Thomas Brabletz; Ulrich T. Hopt; Dirk Bausch; Birte Kulemann; Tobias Keck; Ulrich F. Wellner

BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is characterized by an aggressive biology and poor prognosis. Experimental evidence has suggested a role for the transcriptional repressor Zinc finger E-box binding homeobox 1 (ZEB1) in epithelial-mesenchymal transition, invasion, and metastasis in PDAC. ZEB1 expression has been observed in cancer cells as well as stromal fibroblasts. Our study aimed to evaluate the prognostic value of ZEB1 expression in PDAC tissue. METHODS Patient baseline and follow-up data were extracted from a prospectively maintained database. After clinicopathologic re-review, serial sliced tissue slides were immunostained for ZEB1, E-cadherin, vimentin, and pan-cytokeratin. ZEB1 expression in cancer cells and adjacent stromal fibroblasts was graded separately and correlated to routine histopathologic parameters and survival after resection. RESULTS A total of 117 cases of PDAC were included in the study. High ZEB1 expression in cancer cells and in stromal cancer-associated fibroblasts was associated with poor prognosis. There was also a trend for poor prognosis with a lymph node ratio of greater than 0.10. In line with its role as an inducer of epithelial-mesenchymal transition, ZEB1 expression in cancer cells was positively correlated with Vimentin expression and negatively with E-Cadherin expression. In multivariate analysis, stromal ZEB1 expression grade was the only independent factor of survival after resection. CONCLUSION Our data suggest that ZEB1 expression in cancer cells as well as in stromal fibroblasts are strong prognostic factors in PDAC. Stromal ZEB1 expression is identified for the first time as an independent predictor of survival after resection of PDAC. This observation suggests that therapies targeting ZEB1 and its downstream pathways could hit both cancer cells and supporting cancer-associated fibroblasts.


Modern Pathology | 2012

Heterogeneity of ERBB2 amplification in adenocarcinoma, squamous cell carcinoma and large cell undifferentiated carcinoma of the lung

Tobias Grob; Ivonne Kannengiesser; Maria C. Tsourlakis; Djordje Atanackovic; Alexandra M. Koenig; Yogesh K. Vashist; Hans Klose; Andreas Marx; Susan Koops; Ronald Simon; Jakob R. Izbicki; Carsten Bokemeyer; Guido Sauter; Waldemar Wilczak

The HER2 protein, encoded by the ERBB2 gene, is a molecular target for the treatment of breast and gastric cancer by monoclonal antibodies or tyrosine kinase inhibitors. While intratumoral heterogeneity of ERBB2 amplification is rare in breast cancer it is reported to be frequent in bladder and colorectal cancer. To address the potential heterogeneity of the HER2 status in adenocarcinomas, squamous cell carcinomas and large cell undifferentiated carcinomas of the lung, 590 tumors were analyzed for HER2 overexpression and ERBB2 amplification using FDA-approved reagents for immunohistochemistry and fluorescence in-situ hybridization (FISH). Moderate and strong immunostaining (2+, 3+) was seen in 10% of the tumors. ERBB2 amplification was found in 17 (3%) lung cancer patients including 10 cases (2%) with high-level amplification forming gene clusters. ERBB2 amplification was significantly related to histologic subtype and tumor grade, resulting in 12% ERBB2 amplified tumors in the subgroup of high-grade adenocarcinomas. Heterogeneity was analyzed in all highly amplified tumors. For this purpose, all available tumor tissue blocks from these patients were evaluated. Heterogeneity of ERBB2 amplification was found in 4 of 10 tumors as assessed by FISH. These included two tumors with a mixture of low-level and high-level amplification and two tumors with non-amplified tumor areas next to regions with high-level ERBB2 amplification. High-level ERBB2 amplification occurs in a small fraction of lung cancers with a strong propensity to high-grade adenocarcinomas. Heterogeneity of amplification may limit the utility of anti-HER2 therapy in some of these tumors. Further attempts to assess the utility of HER2-targeting therapy in homogeneously amplified lung cancers appear to be justified.

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