Stratifying esophago-gastric cancer treatment using a patient-derived organoid-based threshold.

BACKGROUND AND AIMS: This study sought to determine the value of patient-derived organoids (PDOs) from esophago-gastric adenocarcinoma (EGC) for response prediction to neoadjuvant chemotherapy (neoCTx). METHODS: Endoscopic biopsies of patients with locally advanced EGC (n = 120) were taken into culture and PDOs expanded. PDOs' response towards the single substances of the FLOT regimen and the combination treatment were correlated to patients' pathological response using tumor regression grading. A classifier based on FLOT response of PDOs was established in an exploratory cohort (n = 13) and subsequently confirmed in an independent validation cohort (n = 13). RESULTS: EGC PDOs reflected patients' diverse responses to single chemotherapeutics and the combination regimen FLOT. In the exploratory cohort, PDOs response to single 5-FU and FLOT combination treatment correlated with the patients' pathological response (5-FU: Kendall's τ = 0.411, P = 0.001; FLOT: Kendall's τ = 0.694, P = 2.541e-08). For FLOT testing, a high diagnostic precision in receiver operating characteristic (ROC) analysis was reached with an AUCROC of 0.994 (CI 0.980 to 1.000). The discriminative ability of PDO-based FLOT testing allowed the definition of a threshold, which classified in an independent validation cohort FLOT responders from non-responders with high sensitivity (90%), specificity (100%) and accuracy (92%). CONCLUSION: In vitro drug testing of EGC PDOs has a high predictive accuracy in classifying patients' histological response to neoadjuvant FLOT treatment. Taking into account the high rate of successful PDO expansion from biopsies, the definition of a threshold that allows treatment stratification paves the way for an interventional trial exploring PDO-guided treatment of EGC patients.

Detecting drug resistance in pancreatic cancer organoids guides optimized chemotherapy treatment.

Drug combination therapies for cancer treatment show high efficacy but often induce severe side effects, resulting in dose or cycle number reduction. We investigated the impact of neoadjuvant chemotherapy (neoCTx) adaptions on treatment outcome in 59 patients with pancreatic ductal adenocarcinoma (PDAC). Resections with tumor-free margins were significantly more frequent when full-dose neoCTx was applied. We determined if patient-derived organoids (PDOs) can be used to personalize poly-chemotherapy regimens by pharmacotyping of treatment-naïve and post-neoCTx PDAC PDOs. Five out of ten CTx-naïve PDO lines exhibited a differential response to either the FOLFIRINOX or the Gem/Pac regimen. NeoCTx PDOs showed a poor response to the neoadjuvant regimen that had been administered to the respective patient in 30% of cases. No significant difference in PDO response was noted when comparing modified treatments in which the least effective single drug was removed from the complete regimen. Drug testing of CTx-naïve PDAC PDOs and neoCTx PDOs may be useful to guide neoadjuvant and adjuvant regimen selection, respectively. Personalizing poly-chemotherapy regimens by omitting substances with low efficacy could potentially result in less severe side effects, thereby increasing the fraction of patients receiving a full course of neoadjuvant treatment. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Development and validity evidence of an objective structured assessment of technical skills score for minimally invasive linear-stapled, hand-sewn intestinal anastomoses: the A-OSATS score.

INTRODUCTION: The aim of this study was to develop a reliable objective structured assessment of technical skills (OSATS) score for linear-stapled, hand-sewn closure of enterotomy intestinal anastomoses (A-OSATS). MATERIALS AND METHODS: The Delphi methodology was used to create a traditional and weighted A-OSATS score highlighting the more important steps for patient outcomes according to an international expert consensus. Minimally invasive novices, intermediates, and experts were asked to perform a minimally invasive linear-stapled intestinal anastomosis with hand-sewn closure of the enterotomy in a live animal model either laparoscopically or robot-assisted. Video recordings were scored by two blinded raters assessing intrarater and interrater reliability and discriminative abilities between novices (n = 8), intermediates (n = 24), and experts (n = 8). RESULTS: The Delphi process included 18 international experts and was successfully completed after 4 rounds. A total of 4 relevant main steps as well as 15 substeps were identified and a definition of each substep was provided. A maximum of 75 points could be reached in the unweighted A-OSATS score and 170 points in the weighted A-OSATS score respectively. A total of 41 anastomoses were evaluated. Excellent intrarater (r = 0.807-0.988, p < 0.001) and interrater (intraclass correlation coefficient = 0.923-0.924, p < 0.001) reliability was demonstrated. Both versions of the A-OSATS correlated well with the general OSATS and discriminated between novices, intermediates, and experts defined by their OSATS global rating scale. CONCLUSION: With the weighted and unweighted A-OSATS score, we propose a new reliable standard to assess the creation of minimally invasive linear-stapled, hand-sewn anastomoses based on an international expert consensus. Validity evidence in live animal models is provided in this study. Future research should focus on assessing whether the weighted A-OSATS exceeds the predictive capabilities of patient outcomes of the unweighted A-OSATS and provide further validity evidence on using the score on different anastomotic techniques in humans.

Predicting postoperative pancreatic fistula in pancreatic head resections: which score fits all?

PURPOSE: Postoperative pancreatic fistula (POPF) is a major complication of pancreatic surgery and can be fatal. Better stratification of patients into risk groups may help to select those who might benefit from strategies to prevent complications. The aim of this study was to validate ten prognostic scores in patients who underwent pancreatic head surgery. METHODS: A total of 364 patients were included in this study between September 2012 and August 2017. Ten risk scores were applied to this cohort. Univariate and multivariate analyses were performed considering all risk factors in the scores. Furthermore, the stratification of patients into risk categories was statistically tested. RESULTS: Nine of the scores (Ansorge et al., Braga et al., Callery et al., Graham et al., Kantor et al., Mungroop et al., Roberts et al., Yamamoto et al. and Wellner et al.) showed strong prognostic stratification for developing POPF (p < 0.001). There was no significant prognostic value for the Fujiwara et al. risk score. Histology, pancreatic duct diameter, intraabdominal fat thickness in computed tomography findings, body mass index, and C-reactive protein were independent prognostic factors on multivariate analysis. CONCLUSION: Most risk scores tend to stratify patients correctly according to risk for POPF. Nevertheless, except for the fistula risk score (Callery et al.) and its alternative version (Mungroop et al.), many of the published risk scores are obscure even for the dedicated pancreatic surgeon in terms of their clinical practicability. There is a need for future studies to provide strategies for preventing POPF and managing patients with high-risk stigmata.

Antibiotic resistance patterns of bacterial bile cultures during pancreatic surgery-a single center analysis and systematic review.

BACKGROUND: Septic complications after pancreatic surgery are common. However, it remains unclear if and how a shift of the microbiological spectrum affects morbidity. The aim of the present study was to assess the microbiological spectrum and antibiotic resistance patterns and their impact on outcome. METHODS: We conducted a retrospective study including patients undergoing pancreatic surgery at our center between 2005 and 2018. A systematic literature review and descriptive meta-analysis of the published and original data was performed according to the PRISMA guidelines. RESULTS: A total of 318 patients were included in the analysis. Patients with biliary drainage had a significantly higher incidence of bacterobilia (93% vs. 25%) and received preoperative antibiotics (46% vs. 12%). The analyzed bile cultures showed no resistance to piperacillin/tazobactam, fluoroquinolones, or carbapenems. Resistance to cefuroxime was seen in 58% of the samples of patients without biliary drainage (NBD) and 93% of the samples of those with drainage (BD). In general, there was no significant difference in overall postoperative morbidity. However, superficial surgical site infections (SSIs) were significantly more common in the BD group. We included a total of six studies and our own data (1627 patients) in the descriptive meta-analysis. The percentage of positive bile cultures ranged from 53 to 81%. In patients with BD, the most frequent microorganisms were Enterococcus spp. (58%), Klebsiella spp. (29%), and E. coli (27%). Almost all studies demonstrated resistance to first- and second-generation cephalosporins and to third- and fourth-generation cephalosporins for patients with BD. CONCLUSION: A change in perioperative antibiotic strategy according to local resistance patterns, especially after BD, might be useful for patients undergoing pancreatic surgery. Appropriate perioperative antibiotic coverage may help to prevent abdominal infectious complications and especially superficial SSIs.

Selective decontamination of the digestive tract in colorectal surgery reduces anastomotic leakage and costs: a propensity score analysis.

PURPOSE: Anastomotic leakage (AL) and surgical site infection (SSI) account for most postoperative complications in colorectal surgery. The aim of this retrospective trial was to investigate whether perioperative selective decontamination of the digestive tract (SDD) reduces these complications and to provide a cost-effectiveness model for elective colorectal surgery. METHODS: All patients operated between November 2016 and March 2020 were included in our analysis. Patients in the primary cohort (PC) received SDD and those in the historical control cohort (CC) did not receive SDD. In the case of rectal/sigmoid resection, SDD was also applied via a transanally placed Foley catheter (TAFC) for 48 h postoperatively. A propensity score-matched analysis was performed to identify risk factors for AL and SSI. Costs were calculated based on German diagnosis-related group (DRG) fees per case. RESULTS: A total of 308 patients (154 per cohort) with a median age of 62.6 years (IQR 52.5-70.8) were analyzed. AL was observed in ten patients (6.5%) in the PC and 23 patients (14.9%) in the CC (OR 0.380, 95% CI 0.174-0.833; P = 0.016). SSI occurred in 14 patients (9.1%) in the PC and 30 patients in the CC (19.5%), representing a significant reduction in our SSI rate (P = 0.009). The cost-effectiveness analysis showed that SDD is highly effective in saving costs with a number needed to treat of 12 for AL and 10 for SSI. CONCLUSION: SDD significantly reduces the incidence of AL and SSI and saves costs for the general healthcare system.

Robotic-assisted minimally invasive Ivor Lewis esophagectomy within the prospective multicenter German da Vinci Xi registry trial.

PURPOSE: Robotic-assisted minimally invasive esophagectomy (RAMIE) has become one standard approach for the operative treatment of esophageal tumors at specialized centers. Here, we report the results of a prospective multicenter registry for standardized RAMIE. METHODS: The German da Vinci Xi registry trial included all consecutive patients who underwent RAMIE at five tertiary university centers between Oct 17, 2017, and Jun 5, 2020. RAMIE was performed according to a standard technique using an intrathoracic circular stapled esophagogastrostomy. RESULTS: A total of 220 patients were included. The median age was 64 years. Total minimally invasive RAMIE was accomplished in 85.9%; hybrid resection with robotic-assisted thoracic approach was accomplished in an additional 11.4%. A circular stapler size of ≥28 mm was used in 84%, and the median blood loss and operative time were 200 (IQR: 80-400) ml and 425 (IQR: 335-527) min, respectively. The rate of anastomotic leakage was 13.2% (n=29), whereas the two centers with >70 cases each had rates of 7.0% and 12.0%. Pneumonia occurred in 19.5% of patients, and the 90-day mortality was 3.6%. Cumulative sum analysis of the operative time indicated the end of the learning curve after 22 cases. CONCLUSIONS: High-quality multicenter registry data confirm that RAMIE is a safe procedure and can be reproduced with acceptable leak rates in a multicenter setting. The learning curve is comparably low for experienced robotic surgeons.

More is More? Total Pancreatectomy for Periampullary Cancer as an Alternative in Patients with High-Risk Pancreatic Anastomosis: A Propensity Score-Matched Analysis.

BACKGROUND: Postpancreatectomy morbidity remains significant even in high-volume centers and frequently results in delay or suspension of indicated adjuvant oncological treatment. This study investigated the short-term and long-term outcome after primary total pancreatectomy (PTP) and pylorus-preserving pancreaticoduodenectomy (PPPD) or Whipple procedure, with a special focus on administration of adjuvant therapy and oncological survival. METHODS: Patients who underwent PTP or PPPD/Whipple for periampullary cancer between January 2008 and December 2017 were retrospectively analyzed. Propensity score-matched analysis was performed to compare perioperative and oncological outcomes. Correspondingly, cases of rescue completion pancreatectomy (RCP) were analyzed. RESULTS: In total, 41 PTP and 343 PPPD/Whipple procedures were performed for periampullary cancer. After propensity score matching, morbidity (Clavien-Dindo classification (CDC) ≥ IIIa, 31.7% vs. 24.4%; p = 0.62) and mortality rates (7.3% vs. 2.4%, p = 0.36) were similar in PTP and PPPD/Whipple. Frequency of adjuvant treatment administration (76.5% vs. 78.4%; p = 0.87), overall survival (513 vs. 652 days; p = 0.47), and progression-free survival (456 vs. 454 days; p = 0.95) did not significantly differ. In turn, after RCP, morbidity (CDC ≥ IIIa, 85%) and mortality (40%) were high, and overall survival was poor (median 104 days). Indicated adjuvant therapy was not administered in 77%. CONCLUSIONS: In periampullary cancers, PTP may provide surgical and oncological treatment outcomes comparable with pancreatic head resections and might save patients from RCP. Especially in selected cases with high-risk pancreatic anastomosis or preoperatively impaired glucose tolerance, PTP may provide a safe treatment alternative to pancreatic head resection.

Pancreatoduodenectomy with or without prophylactic falciform ligament wrap around the hepatic artery for prevention of postpancreatectomy haemorrhage: randomized clinical trial (PANDA trial).

BACKGROUND: Postpancreatectomy haemorrhage (PPH) is a rare but potentially fatal complication after pancreatoduodenectomy. Preventive strategies are lacking with scarce data for support. The aim of this study was to investigate whether a prophylactic falciform ligament wrap around the hepatic and gastroduodenal artery can prevent PPH from these vessels. METHODS: In a randomized, controlled, multicentre trial, patients who were scheduled for elective open partial pancreatoduodenectomy with pancreatojejunostomy between 5 November 2015 and 2 April 2020 were randomly allocated in a 1 : 1 ratio to undergo pancreatoduodenectomy with (intervention) or without (control) a falciform ligament wrap around the hepatic artery. The primary endpoint was the rate of clinically relevant PPH from the hepatic artery or gastroduodenal artery stump within 3 months after pancreatoduodenectomy. Secondary endpoints were the rates of associated postoperative complications, for example postoperative pancreatic fistula (POPF) and PPH. RESULTS: Altogether, 445 patients were randomized with 222 and 223 in each group. Among the patients included in modified intention-to-treat analysis (207 in the intervention group and 210 in the control group), the primary endpoint was observed in six of 207 in the intervention group compared with 15 of 210 in the control group (2.9 versus 7.1 per cent respectively; odds ratio 0.39 (95 per cent c.i. 0.15 to 1.02); P = 0.071). Per protocol analysis showed a significant reduction in the intervention group (odds ratio 0.26 (95 per cent c.i. 0.09 to 0.80); P = 0.017). A soft pancreas texture (43 per cent) and the rate of a clinically relevant POPF were evenly (20 per cent) distributed between the groups. The rate of any clinically relevant PPH including the primary endpoint and other bleeding sites was not significantly different between intervention and control groups (9.7 versus 14.8 per cent respectively). CONCLUSION: A falciform ligament wrap may reduce PPH from the hepatic artery or gastroduodenal artery stump and should be considered during pancreatoduodenectomy. REGISTRATION NUMBER: NCT02588066 (http://www.clinicaltrials.gov).

Pelvic exenteration for colorectal and non-colorectal cancer: a comparison of perioperative and oncological outcome.

BACKGROUND: Pelvic exenteration (PE) is the only option for long-term cure of advanced cancer originating from different types of tumor or recurrent disease in the lower pelvis. The aim was to show differences between colorectal and non-colorectal cancer in survival and postoperative morbidity. METHODS: Retrospective data of 63 patients treated with total pelvic exenteration between 2013 and 2018 are reported. Pre-, intra-, and postoperative parameters, survival data, and risk factors for complications were analyzed. RESULTS: A total of 57.2% (n = 37) of the patients had colorectal cancer, 22.3% had gynecological malignancies (vulvar (n = 6) or cervical (n = 8) cancer), 11.1% (n = 7) had anal cancer, and 9.5% had other primary tumors. A total of 30.2% (n = 19) underwent PE for a primary tumor and 69.8% (n = 44) for recurrent cancer. The 30-day in-hospital mortality was 0%. Neoadjuvant treatment was administered to 65.1% (n = 41) of the patients and correlated significantly with postoperative complications (odds ratio 4.441; 95% CI: 1.375-14.342, P > 0.05). R0, R1, R2, and Rx resections were achieved in 65.1%, 19%, 1.6%, and 14.3% of the patients, respectively. In patients undergoing R0 resection, 2-year OS and RFS were 73.2% and 52.4%, respectively. Resection status was a significant risk factor for recurrence-free and overall survival (OS) in univariate analysis. Multivariate analysis revealed age (P = 0.021), ASA ≥ 3 (P = 0.005), high blood loss (P = 0.028), low preoperative hemoglobin level (P < 0.001), nodal positivity (P < 0.001), and surgical complications (P = 0.003) as independent risk factors for OS. CONCLUSION: Pelvic exenteration is a procedure with high morbidity rates but remains the only curative option for advanced or recurrent colorectal and non-colorectal cancer in the pelvis.

Impact of resection margin status on survival in advanced N stage pancreatic cancer - a multi-institutional analysis.

BACKGROUND: The present study aimed to examine the impact of microscopically tumour-infiltrated resection margins (R1) in pancreatic ductal adenocarcinoma (PDAC) patients with advanced lymphonodular metastasis (pN1-pN2) on overall survival (OS). METHODS: This retrospective, multi-institutional analysis included patients undergoing surgical resection for PDAC at three tertiary university centres between 2005 and 2018. Subcohorts of patients with lymph node status pN0-N2 were stratified according to the histopathological resection status using Kaplan-Meier survival analysis. RESULTS: The OS of the entire cohort (n = 620) correlated inversely with the pN status (26 [pN0], 18 [pN1], 11.8 [pN2] months, P < 0.001) and R status (21.7 [R0], 12.5 [R1] months, P < 0.001). However, there was no statistically significant OS difference between R0 versus R1 in cases with advanced lymphonodular metastases: 19.6 months (95% CI: 17.4-20.9) versus 13.6 months (95% CI: 10.7-18.0) for pN1 stage and 13.7 months (95% CI: 10.7-18.9) versus 10.1 months (95% CI: 7.9-19.1) for pN2, respectively. Accordingly, N stage-dependent Cox regression analysis revealed that R status was a prognostic factor in pN0 cases only. Furthermore, there was no significant survival disadvantage for patients with R0 resection but circumferential resection margin invasion (≤ 1 mm; CRM+; 10.7 months) versus CRM-negative (13.7 months) cases in pN2 stages (P = 0.5). CONCLUSIONS: An R1 resection is not associated with worse OS in pN2 cases. If there is evidence of advanced lymph node metastasis and a re-resection due to an R1 situation (e.g. at venous or arterial vessels) may substantially increase the perioperative risk, margin clearance in order to reach local control might be avoided with respect to the OS.

Impact of pulmonary embolism on morbidity and mortality in patients undergoing pancreatic surgery.

PURPOSE: Postoperative pulmonary embolism (PE) after pancreatic surgery is a potentially life-threatening complication. However, the magnitude of morbidity and mortality of PE is still uncertain. The present study aims to assess the incidence of PE after pancreatic surgery and analyze its impact on the outcome. METHODS: We conducted a retrospective study including all patients who underwent pancreatic resections between 2005 and 2017. The development of PE was analyzed for a 90-day period following surgery. Risk factors were evaluated using regression models. RESULTS: The study investigated 947 patients undergoing pancreatic surgery. Overall, 26 (2.7%) patients developed PE. The median body mass index (BMI) of patients with PE was significantly higher (28.1 kg/m2 [24.7-31.8] vs. 24.8 kg/m2 [22.4-27.8], p < 0.001). Patients with PE had a significantly increased duration of the operation and more often underwent multivisceral resections. The lowest incidence of PE was found after distal or total pancreatectomy (2%). In median, PE occurred on the fifth postoperative day (interquartile range: 3-9). Increased BMI, duration of operation, and postoperative deep venous thrombosis were found to be multivariate risk factors for the development of PE. Importantly, postoperative complications (53.8% vs. 15.1%, p < 0.001) and the 30-day mortality rate were significantly increased in the PE group (19.2% vs. 3.3%, p < 0.001). CONCLUSIONS: Patients with increased BMI, a history of deep venous thrombosis, and multivisceral resections are a high-risk group for PE after pancreatic surgery. While the absolute incidence and related mortality of PE after pancreatic surgery is low, it is associated with severe sequelae.

Mouse Models of Human Gastric Cancer Subtypes With Stomach-Specific CreERT2-Mediated Pathway Alterations.

BACKGROUND & AIMS: Patterns of genetic alterations characterize different molecular subtypes of human gastric cancer. We aimed to establish mouse models of these subtypes. METHODS: We searched databases to identify genes with unique expression in the stomach epithelium, resulting in the identification of Anxa10. We generated mice with tamoxifen-inducible Cre recombinase (CreERT2) in the Anxa10 gene locus. We created 3 mouse models with alterations in pathways that characterize the chromosomal instability (CIN) and the genomically stable (GS) subtypes of human gastric cancer: Anxa10-CreERT2;KrasG12D/+;Tp53R172H/+;Smad4fl/f (CIN mice), Anxa10-CreERT2;Cdh1fl/fl;KrasG12D/+;Smad4fl/fl (GS-TGBF mice), and Anxa10-CreERT2;Cdh1fl/fl;KrasG12D/+;Apcfl/fl (GS-Wnt mice). We analyzed tumors that developed in these mice by histology for cell types and metastatic potential. We derived organoids from the tumors and tested their response to chemotherapeutic agents and the epithelial growth factor receptor signaling pathway inhibitor trametinib. RESULTS: The gastric tumors from the CIN mice had an invasive phenotype and formed liver and lung metastases. The tumor cells had a glandular morphology, similar to human intestinal-type gastric cancer. The gastric tumors from the GS-TGFB mice were poorly differentiated with diffuse morphology and signet ring cells, resembling human diffuse-type gastric cancer. Cells from these tumors were invasive, and mice developed peritoneal carcinomatosis and lung metastases. GS-Wnt mice developed adenomatous tooth-like gastric cancer. Organoids derived from tumors of GS-TGBF and GS-Wnt mice were more resistant to docetaxel, whereas organoids from the CIN tumors were more resistant to trametinib. CONCLUSIONS: Using a stomach-specific CreERT2 system, we created mice that develop tumors with morphologic similarities to subtypes of human gastric cancer. These tumors have different patterns of local growth, metastasis, and response to therapeutic agents. They can be used to study different subtypes of human gastric cancer.

Prognostic impact of para-aortic lymph node metastases in non-pancreatic periampullary cancer.

BACKGROUND: Resection of the para-aortic lymph node (PALN) group Ln16b1 during pancreatoduodenectomy remains controversial because PALN metastases are associated with a worse prognosis in pancreatic cancer patients. The present study aimed to analyze the impact of PALN metastases on outcome after non-pancreatic periampullary cancer resection. METHODS: One hundred sixty-four patients with non-pancreatic periampullary cancer who underwent curative pancreatoduodenectomy or total pancreatectomy between 2005 and 2016 were retrospectively investigated. The data were supplemented with a systematic literature review on this topic. RESULTS: In 67 cases, the PALNs were clearly assigned and could be histopathologically analyzed. In 10.4% of cases (7/67), tumor-infiltrated PALNs (PALN+) were found. Metastatic PALN+ stage was associated with increased tumor size (P = 0.03) and a positive nodal stage (P < 0.001). The median overall survival (OS) of patients with metastatic PALN and non-metastatic PALN (PALN-) was 24.8 and 29.5 months, respectively. There was no significant difference in the OS of PALN+ and pN1 PALN patients (P = 0.834). Patients who underwent palliative surgical treatment (n = 20) had a lower median OS of 13.6 (95% confidence interval 2.7-24.5) months. Including the systematic literature review, only 23 cases with PALN+ status and associated OS could be identified; the average survival was 19.8 months. CONCLUSION: PALN metastasis reflects advanced tumor growth and lymph node spread; however, it did not limit overall survival in single-center series. The available evidence of the prognostic impact of PALN metastasis is scarce and a recommendation against resection in these cases cannot be given.

Human gastric cancer modelling using organoids.

OBJECTIVE: Gastric cancer is the second leading cause of cancer-related deaths and the fifth most common malignancy worldwide. In this study, human and mouse gastric cancer organoids were generated to model the disease and perform drug testing to delineate treatment strategies. DESIGN: Human gastric cancer organoid cultures were established, samples classified according to their molecular profile and their response to conventional chemotherapeutics tested. Targeted treatment was performed according to specific druggable mutations. Mouse gastric cancer organoid cultures were generated carrying molecular subtype-specific alterations. RESULTS: Twenty human gastric cancer organoid cultures were established and four selected for a comprehensive in-depth analysis. Organoids demonstrated divergent growth characteristics and morphologies. Immunohistochemistry showed similar characteristics to the corresponding primary tissue. A divergent response to 5-fluoruracil, oxaliplatin, irinotecan, epirubicin and docetaxel treatment was observed. Whole genome sequencing revealed a mutational spectrum that corresponded to the previously identified microsatellite instable, genomic stable and chromosomal instable subtypes of gastric cancer. The mutational landscape allowed targeted therapy with trastuzumab for ERBB2 alterations and palbociclib for CDKN2A loss. Mouse cancer organoids carrying Kras and Tp53 or Apc and Cdh1 mutations were characterised and serve as model system to study the signalling of induced pathways. CONCLUSION: We generated human and mouse gastric cancer organoids modelling typical characteristics and altered pathways of human gastric cancer. Successful interference with activated pathways demonstrates their potential usefulness as living biomarkers for therapy response testing.

Detectability and structural stability of a liquid fiducial marker in fresh ex vivo pancreas tumour resection specimens on CT and 3T MRI.

PURPOSE: To test the detectability of a liquid fiducial marker injected into ex vivo pancreas tumour tissue on magnetic resonance imaging (MRI) and computed tomography (CT). Furthermore, its injection performance using different needle sizes and its structural stability after fixation in formaldehyde were investigated. METHODS: Liquid fiducial markers with a volume of 20-100 µl were injected into freshly resected pancreas specimens of three patients with suspected adenocarcinoma. X­ray guided injection was performed using different needle sizes (18 G, 22 G, 25 G). The specimens were scanned on MRI and CT with clinical protocols. The markers were segmented on CT by signal thresholding. Marker detectability in MRI was assessed in the registered segmentations. Marker volume on CT was compared to the injected volume as a measure of backflow. RESULTS: Markers with a volume ≥20 µl were detected as hyperintensity on X­ray and CT. On T1- and T2-weighted 3T MRI, marker sizes ranging from 20-100 µl were visible as hypointensity. Since most markers were non-spherical, MRI detectability was poor and their differentiation from hypointensities caused by air cavities or surgical clips was only feasible with a reference CT. Marker backflow was only observed when using an 18-G needle. A volume decrease of 6.6 ± 13.0% was observed after 24 h in formaldehyde and, with the exception of one instance, no wash-out occurred. CONCLUSIONS: The liquid fiducial marker injected in ex vivo pancreatic resection specimen was visible as hyperintensity on kV X­ray and CT and as hypointensity on MRI. The marker's size was stable in formaldehyde. A marker volume of ≥50 µL is recommended in clinically used MRI sequences. In vivo injection is expected to improve the markers sphericity due to persisting metabolism and thereby enhance detectability on MRI.

EUS-guided drainage in the management of postoperative pancreatic leaks and fistulas (with video).

BACKGROUND AND AIMS: Postoperative pancreatic leakage and fistulae (POPF) are a leading adverse event after partial pancreatic resection. Treatment algorithms are currently not standardized. Evidence regarding the role of endoscopy is scarce. METHODS: One hundred ninety-six POPF patients with (n = 132) and without (n = 64) concomitant pancreatic fluid collections (PFCs) from centers in Berlin, Kiel, and Dresden were analyzed retrospectively. Clinical resolution was used as the primary endpoint of analysis. RESULTS: Analysis was stratified by the presence or absence of a PFC because these patients differed in treatment pathway and the presence of systemic inflammation with a median C-reactive protein of 30.7 mg/dL in patients without a PFC versus 131.0 mg/dL in patients with a PFC (P = 3.4 × 10-4). In patients with PFCs, EUS-guided intervention led to resolution in a median of 8 days as compared with 25 days for percutaneous drainage and 248 days for surgery (P = 3.75 × 10-14). There was a trend toward a higher success rate of EUS-guided intervention as a primary treatment modality with 85% (P = .034), followed by percutaneous drainage (64%) and surgery (41%). When applied as a rescue intervention (n = 24), EUS led to clinical resolution in 96% of cases. In patients without PFCs, EUS-guided internalization in a novel endoscopic technique led to resolution after a median of 4 days as compared with 51 days for a remaining surgical drainage (P = 9.3 × 10-9). CONCLUSIONS: In this retrospective analysis, EUS-guided drainage of POPF led to a more rapid resolution. EUS may be considered as a viable option in the management of PFCs and POPF and should be evaluated in prospective studies.

Results of portosystemic shunts during extended pancreatic resections.

PURPOSE: Patients with borderline resectable pancreatic cancer are increasingly explored after neoadjuvant treatment protocols. A complete resection, then, frequently includes the resection of the mesentericoportal axis. Portosystemic shunting for advanced tumours with infiltration of the splenic vein or cavernous transformation of the portal vein can enable complete tumour resection and prevent portovenous congestion of the intestine. The aim of this study was to report the results of this technique for selected patients. METHODS: Patients operated for pancreatic cancer at our department between September 2012 and December 2017 using intraoperative portosystemic shunting were included in this retrospective analysis. RESULTS: Some 11 patients with pancreatectomy and simultaneous portosystemic shunting were included. The median age was 65.1 years. A distal splenorenal shunt and a temporary mesocaval shunt were accomplished in 5 and 4 cases, respectively. Two patients were operated using persistent mesocaval shunts (from the coronary, splenic or inferior mesenteric veins). The median operating time was 9.43 h. All but one patient were resected with tumour-negative resection margins; 5 patients had relevant complicated postoperative courses. There was one case of in-hospital mortality but no further 30- or 90-day mortality or graft-associated complications. Five patients were alive after a median follow-up of 24.6 months. The median postoperative survival was 12 months. CONCLUSION: Portosystemic shunting at the time of extended pancreatectomy is technically challenging but feasible and enables complete tumour resection in cases in which standard vascular reconstruction is limited by cavernous transformation or to prevent sinistral portal hypertension with acceptable morbidity in selected cases. Considering the limited overall survival, the potential individual patient benefit needs to be weighed against the considerable morbidity of advanced tumour resections.

Validation of prognostic risk scores for patients undergoing resection for pancreatic cancer.

BACKGROUND/OBJECTIVES: A better stratification of patients into risk groups might help to select patients who might benefit from more aggressive therapy. The aim of this study was to validate five prognostic scores in patients resected for pancreatic ductal adenocarcinoma (PDAC). METHODS: Included were 307 PDAC patients who underwent resection with curative intent. Five clinical risk scores were selected and applied to our study population. Survival analyses were carried out using univariate and multivariate proportional hazards regression. RESULTS: Prognostic stratification was strong for the Heidelberg score (p < 0.001) and the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram (p = 0.001) and moderate for the Botsis score (p = 0.033). There was no significant prognostic value for the Early Mortality Risk Score (p = 0.126) and McGill Brisbane Symptom Score (p = 0.133). Positive resection margin (HR 1.53, 95% CI 1.08-2.16) and pain [pain (HR 1.40, CI 1.03-1.91), back pain (HR 1.67, 95% CI 1.08-2.57)] were independent prognostic factors on multivariate analysis. CONCLUSIONS: The Heidelberg score and MSKCC nomogram provided adequate risk stratification in our independent study cohort. Further studies in independent patient cohorts are required to achieve higher levels of validation.

Prognostic Impact of Bacterobilia on Morbidity and Postoperative Management After Pancreatoduodenectomy: A Systematic Review and Meta-analysis.

BACKGROUND: Intraoperative bile analysis during pancreatoduodenectomy (PD) is performed routinely at specialized centers worldwide. However, it remains controversial if and how intraoperative bacterobilia during PD affects morbidity and its management. The aim of the study was a systematic review and meta-analysis of intraoperative bacterobilia and its impact on patient outcome after PD. METHODS: Five relevant outcomes of interest were defined, and a systematic review of the literature with meta-analysis was performed according to the PRISMA guidelines. RESULTS: A total of 28 studies (8523 patients) were included. The median incidence of bacterobilia was 58% (interquartile range 51-67%). The most frequently isolated bacteria were Enterococcus species (51%), Klebsiella species (28%), and Escherichia coli (27%). Preoperative biliary drainage was significantly associated with bacterobilia (86 vs. 25%; RR 3.27; 95% confidence interval (CI) 2.42-4.42; p < 0.001). The incidence of surgical site infections (SSI) was significantly increased in cases with bacterobilia (RR 2.84; 95% CI 2.17-3.73; p < 0.001). Postoperative pancreatic fistula, overall postoperative morbidity, and mortality were not significantly influenced. Identical bacteria in bile and the infectious sources were found in 48% (interquartile range 34-59%) of the cases. CONCLUSIONS: Bacterobilia is detected during almost every second PD and is associated with an increased rate of SSI. The microbiome from intraoperative bile and postoperative infectious sources match in ~50% of patients, providing the option of early administration of calculated antibiotics and the determination of resistance patterns.