Frieder Berr

Prof. Dr. Frieder Berr


Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2015 in World Journal of Gastroenterology
Verified
Journal Article
Open access
TOTsuneo Oyama
Tsuneo Oyama
NYNaohisa Yahagi
Naohisa Yahagi
TPThierry Ponchon
Thierry Ponchon
TKTobias Kiesslich
Tobias Kiesslich
FBFrieder Berr
Frieder Berr
Endoscopic submucosal dissection (ESD) has been invented in Japan to provide resection for cure of early cancer in the gastrointestinal tract. Professional level of ESD requires excellent staging of early neoplasias with image enhanced endoscopy (IEE) to make correct indications for ESD, and high skills in endoscopic electrosurgical dissection. In Japan, endodiagnostic and endosurgical excellence spread through personal tutoring of skilled endoscopists by the inventors and experts in IEE and ESD. To translocate this expertise to other continents must overcome two fundamental obstacles: (1) inadequate expectations as to the complexity of IEE and ESD; and (2) lack of suitable lesions and master-mentors for ESD trainees. Leading endoscopic mucosal resection-proficient endoscopists must pioneer themselves through the long learning curve to proficient ESD experts. Major referral centers for ESD must arise in Western countries on comparable professional level as in Japan. In the second stage, the upcoming Western experts must commit themselves to teach skilled endoscopists from other referral centers, in order to spread ESD in Western countries. Respect for patients with early gastrointestinal cancer asks for best efforts to learn endoscopic categorization of early neoplasias and skills for ESD based on sustained cooperation with the masters in Japan. The strategy is discussed here.

22 July 2015 in Hepatology
Verified
Journal Article
Closed access
PDF file
AWAndrej Wagner
Andrej Wagner
UDUlrike W. Denzer
Ulrike W. Denzer
DNDaniel Neureiter
Daniel Neureiter
TKTobias Kiesslich
Tobias Kiesslich
APAndreas Puespoeck
Andreas Puespoeck
GWGernot W. Wolkersdörfer
Gernot W. Wolkersdörfer

23 June 2015 in BMC Complementary and Alternative Medicine
Verified
Journal Article
Open access
PDF file
CMChristian Mayr
Christian Mayr
AWAndrej Wagner
Andrej Wagner
Daniel NeureiterDaniel Neureiter
Daniel Neureiter
MPMartin Pichler
Martin Pichler
MJMartin Jakab
Martin Jakab
TKTobias Kiesslich
Tobias Kiesslich
The green tea catechin epigallocatechin gallate (EGCG) was shown to effectively inhibit tumor growth in various types of cancer including biliary tract cancer (BTC). For most BTC patients only palliative therapy is possible, leading to a median survival of about one year. Chemoresistance is a major problem that contributes to the high mortality rates of BTC. The aim of this study was to investigate the cytotoxic effect of EGCG alone or in combination with cisplatin on eight BTC cell lines and to investigate the cellular anti-cancer mechanisms of EGCG. The effect of EGCG treatment alone or in combination with the standard chemotherapeutic cisplatin on cell viability was analyzed in eight BTC cell lines. Additionally, we analyzed the effects of EGCG on caspase activity, cell cycle distribution and gene expression in the BTC cell line TFK-1. EGCG significantly reduced cell viability in all eight BTC cell lines (p < 0.05 or p < 0.01, respectively, for most cell lines and EGCG concentrations > 5 μM). Combined EGCG and cisplatin treatment showed a synergistic cytotoxic effect in five cell lines and an antagonistic effect in two cell lines. Furthermore, EGCG reduced the mRNA levels of various cell cycle-related genes, while increasing the expression of the cell cycle inhibitor p21 and the apoptosis-related death receptor 5 (p < 0.05). This observation was accompanied by an increase in caspase activity and cells in the sub-G1 phase of the cell cycle, indicating induction of apoptosis. EGCG also induced a down-regulation of expression of stem cell-related genes and genes that are associated with an aggressive clinical character of the tumor, such as cd133 and abcg2. EGCG shows various anti-cancer effects in BTC cell lines and might therefore be a potential anticancer drug for future studies in BTC. Additionally, EGCG displays a synergistic cytotoxic effect with cisplatin in most tested BTC cell lines.

Verified
Journal Article
Open access
PDF file
AWAndrej Wagner
Andrej Wagner
MWMarcus Wiedmann
Marcus Wiedmann
ATAndrea Tannapfel
Andrea Tannapfel
CMChristian Mayr
Christian Mayr
TKTobias Kiesslich
Tobias Kiesslich
HWHelmut Witzigmann
Helmut Witzigmann
Hilar cholangiocarcinoma (CC) is non-resectable in the majority of patients often due to intrahepatic extension along bile duct branches/segments, and even after complete resection (R0) recurrence can be as high as 70%. Photodynamic therapy (PDT) is an established palliative local tumor ablative treatment for non-resectable hilar CC. We report the long-term outcome of curative resection (R0) performed after neoadjuvant PDT for downsizing of tumor margins in seven patients (median age 59 years) with initially non-resectable hilar CC. Photofrin® was injected intravenously 24–48 h before laser light irradiation of the tumor stenoses and the adjacent bile duct segments. Major resective surgery was done with curative intention six weeks after PDT. All seven patients had been curatively (R0) resected and there were no undue early or late complications for the neoadjuvant PDT and surgery. Six of seven patients died from tumor recurrence at a median of 3.2 years after resection, the five-year survival rate was 43%. These results are comparable with published data for patients resected R0 without pre-treatment, indicating that neoadjuvant PDT is feasible and could improve overall survival of patients considered non-curatively resectable because of initial tumor extension in bile duct branches/segments—however, this concept needs to be validated in a larger trial.

8 December 2017 in Digestive Endoscopy
Verified
Journal Article
Open access
PDF file
AWAndrej Wagner
Andrej Wagner
DNDaniel Neureiter
Daniel Neureiter
TKTobias Kiesslich
Tobias Kiesslich
GWGernot W. Wolkersdörfer
Gernot W. Wolkersdörfer
TPThomas Pleininger
Thomas Pleininger
FBFrieder Berr
Frieder Berr
Background and Aim: Colorectal endoscopic submucosal dissection (ESD) shows higher R0 resection and lower local recurrence rates than endoscopic mucosal resection (EMR) in Japan. In Europe, independent learning of ESD in the colorectum is feasible, but yet to be analyzed for curative resection and recurrence rates.Methods: After experimental training under supervision by Japanese experts (T.O., N.Y.), three endoscopists independently carried out 83 ESD procedures intention‐to‐treat for lesions in the entire colorectum of 67 patients in a prospective registry (November 2009 to June 2016).Results: ESD was feasible in 80 (96%) colorectal neoplasias (mean diameter 33.6 [± 1.8] mm), and three more required conversion to piecemeal EMR. The lesions were adenomas in 66% with low‐grade intraepithelial neoplasia (LGIN), 29% with high‐grade intraepithelial neoplasia, and 5% with carcinomas (G2, pT1). ESD had to be facilitated by the final use of snaring (hybrid‐ESD, n = 45), especially in the initial learning period. En‐bloc resection rate was 85%. Complications were microperforations (7%, conducive to one hemicolectomy), and delayed bleeding (1%) without mortality or long‐term morbidity. Residual adenomas with LGIN (5%) after hybrid‐ESD did not recur after endoscopic ablation. All malignant neoplasias (34%) were curatively resected without recurrence after a mean follow up of 19.5 (± 3.2) months.Conclusions: During independent ESD learning in the colorectum, ESD intention‐to‐treat showed a low recurrence rate after appropriate training, and hybrid‐ESD showed acceptable complication and recurrence rates, justifying hybrid‐ESD as a strategy for self‐completion and rescue.

Verified
Journal Article
Open access
PDF file
AWAndrej Wagner
Andrej Wagner
SZStephan Zandanell
Stephan Zandanell
TKTobias Kiesslich
Tobias Kiesslich
Daniel NeureiterDaniel Neureiter
Daniel Neureiter
EKEckhard Klieser
Eckhard Klieser
FBFrieder Berr
Frieder Berr
Background: Meticulous endoscopic characterization of gastrointestinal neoplasias (GN) is crucial to the clinical outcome. Hereby the indication and type of resection (endoscopically, en-bloc or piece-meal, or surgical resection) are determined. By means of established image-enhanced (IEE) and magnification endoscopy (ME) GN can be characterized in terms of malignancy and invasion depth. In this context, the statistical evidence and accuracy of these diagnostic procedures should be elucidated. Here, we present a systematic review of the literature. Results: 21 Studies could be found which met the inclusion criteria. In clinical prospective trials and meta-analyses, the diagnostic accuracy of >90% for characterization of malignant neoplasms could be documented, if ME with IEE was used in squamous cell esophageal cancer, stomach, or colonic GN. Conclusions: Currently, by means of optical diagnosis, today’s gastrointestinal endoscopy is capable of determining the histological subtype, exact lateral spread, and depth of invasion of a lesion. The prerequisites for this are an exact knowledge of the anatomical structures, the endoscopic classifications based on them, and a systematic learning process, which can be supported by training courses. More prospective clinical studies are required, especially in the field of Barrett’s esophagus and duodenal neoplasia.