Robot-assisted versus laparoscopic pancreatoduodenectomy: a pan-European multicenter propensity-matched study.

BACKGROUND: The use of robot-assisted and laparoscopic pancreatoduodenectomy is increasing, yet large adjusted analyses that can be generalized internationally are lacking. This study aimed to compare outcomes after robot-assisted pancreatoduodenectomy and laparoscopic pancreatoduodenectomy in a pan-European cohort. METHODS: An international multicenter retrospective study including patients after robot-assisted pancreatoduodenectomy and laparoscopic pancreatoduodenectomy from 50 centers in 12 European countries (2009-2020). Propensity score matching was performed in a 1:1 ratio. The primary outcome was major morbidity (Clavien-Dindo ≥III). RESULTS: Among 2,082 patients undergoing minimally invasive pancreatoduodenectomy, 1,006 underwent robot-assisted pancreatoduodenectomy and 1,076 laparoscopic pancreatoduodenectomy. After matching 812 versus 812 patients, the rates of major morbidity (31.9% vs 29.6%; P = .347) and 30-day/in-hospital mortality (4.3% vs 4.6%; P = .904) did not differ significantly between robot-assisted pancreatoduodenectomy and laparoscopic pancreatoduodenectomy, respectively. Robot-assisted pancreatoduodenectomy was associated with a lower conversion rate (6.7% vs 18.0%; P < .001) and higher lymph node retrieval (16 vs 14; P = .003). Laparoscopic pancreatoduodenectomy was associated with shorter operation time (446 minutes versus 400 minutes; P < .001), and lower rates of postoperative pancreatic fistula grade B/C (19.0% vs 11.7%; P < .001), delayed gastric emptying grade B/C (21.4% vs 7.4%; P < .001), and a higher R0-resection rate (73.2% vs 84.4%; P < .001). CONCLUSION: This European multicenter study found no differences in overall major morbidity and 30-day/in-hospital mortality after robot-assisted pancreatoduodenectomy compared with laparoscopic pancreatoduodenectomy. Further, laparoscopic pancreatoduodenectomy was associated with a lower rate of postoperative pancreatic fistula, delayed gastric emptying, wound infection, shorter length of stay, and a higher R0 resection rate than robot-assisted pancreatoduodenectomy. In contrast, robot-assisted pancreatoduodenectomy was associated with a lower conversion rate and a higher number of retrieved lymph nodes as compared with laparoscopic pancreatoduodenectomy.

Pancreatic head resection for carcinoma of the ampulla vateri - better long-term prognosis, but more postoperative complications.

BACKGROUND: Pancreatoduodenectomies are complex surgical procedures with a considerable morbidity and mortality even in high-volume centers. However, postoperative morbidity and long-term oncological outcome are not only affected by the surgical procedure itself, but also by the underlying disease. The aim of our study is an analysis of pancreatoduodenectomies for patients with pancreatic ductal adenocarcinoma (PDAC) and ampullary carcinoma (CAMP) concerning postoperative complications and long-term outcome in a tertiary hospital in Germany. METHODS: The perioperative and oncological outcome of 109 pancreatic head resections performed for carcinoma of the ampulla vateri was compared to the outcome of 518 pancreatic head resections for pancreatic ductal adenocarcinoma over a 20 year-period from January 2002 until December 2021. All operative procedures were performed at the University Hospital Freiburg, Germany. Patient data was analyzed retrospectively, using a prospectively maintained SPSS database. Propensity score matching was performed to adjust for differences in surgical and reconstruction technique. Primary outcome of our study was long-term overall survival, secondary outcomes were postoperative complications and 30-day postoperative mortality. Postoperative complications like pancreatic fistula (POPF), postpancreatectomy hemorrhage (PPH) and delayed gastric emptying (DGE) were graded following current international definitions. Survival was estimated using Kaplan Meier curves and log-rank tests. A p-value < 0.05 was considered statistically significant. RESULTS: Operation time was significantly longer in PDAC patients (432 vs. 391 min, p < 0.001). The rate of portal vein resections was significantly higher in PDAC patients (p < 0.001). In CAMP patients, a pancreatogastrostomy as reconstruction technique was performed more frequently compared to PDAC patients (48.6% vs. 29.9%, p < 0.001) and there was a trend towards more laparoscopic surgeries in CAMP patients (p = 0.051). After propensity score matching, we found no difference in DGE B/C and PPH B/C (p = 0.389; p = 0.517), but a significantly higher rate of clinically relevant pancreatic fistula (CR-POPF) in patients with pancreatoduodenectomies due to ampullary carcinoma (30.7% vs. 16.8%, p < 0.001). Long-term survival was significantly better in CAMP patients (42 vs. 24 months, p = 0.003). CONCLUSION: Patients with pancreatoduodenectomies due to ampullary carcinomas showed a better long-term oncological survival, by reason of the better prognosis of this tumor entity. However, these patients often needed a more elaborated postoperative treatment due to the higher rate of clinically relevant pancreatic fistula in this group.

Thoracic Epidural Analgesia Is Not Associated With Improved Survival After Pancreatic Surgery: Long-Term Follow-Up of the Randomized Controlled PAKMAN Trial.

BACKGROUND: Perioperative thoracic epidural analgesia (EDA) and patient-controlled intravenous analgesia (PCIA) are common forms of analgesia after pancreatic surgery. Current guidelines recommend EDA over PCIA, and evidence suggests that EDA may improve long-term survival after surgery, especially in cancer patients. The aim of this study was to determine whether perioperative EDA is associated with an improved patient prognosis compared to PCIA in pancreatic surgery. METHODS: The PAKMAN trial was an adaptive, pragmatic, international, multicenter, randomized controlled superiority trial conducted from June 2015 to October 2017. Three to five years after index surgery a long-term follow-up was performed from October 2020 to April 2021. RESULTS: For long-term follow-up of survival, 109 patients with EDA were compared to 111 patients with PCIA after partial pancreatoduodenectomy (PD). Long-term follow-up of quality of life (QoL) and pain assessment was available for 40 patients with EDA and 45 patients with PCIA (questionnaire response rate: 94%). Survival analysis revealed that EDA, when compared to PCIA, was not associated with improved overall survival (OS, HR, 1.176, 95% HR-CI, 0.809-1.710, P = .397, n = 220). Likewise, recurrence-free survival did not differ between groups (HR, 1.116, 95% HR-CI, 0.817-1.664, P = .397, n = 220). OS subgroup analysis including only patients with malignancies showed no significant difference between EDA and PCIA (HR, 1.369, 95% HR-CI, 0.932-2.011, P = .109, n = 179). Similar long-term effects on QoL and pain severity were observed in both groups (EDA: n = 40, PCIA: n = 45). CONCLUSIONS: Results from this long-term follow-up of the PAKMAN randomized controlled trial do not support favoring EDA over PCIA in pancreatic surgery. Until further evidence is available, EDA and PCIA should be considered similar regarding long-term survival.

Tailoring the Use of Central Pancreatectomy Through Prediction Models for Major Morbidity and Postoperative Diabetes: International Retrospective Multicenter Study.

OBJECTIVE: To develop a prediction model for major morbidity and endocrine dysfunction after CP which could help in tailoring the use of this procedure. SUMMARY BACKGROUND DATA: Central pancreatectomy (CP) is a parenchyma-sparing alternative to distal pancreatectomy for symptomatic benign and pre-malignant tumors in body and neck of the pancreas CP lowers the risk of new-onset diabetes and exocrine pancreatic insufficiency compared to distal pancreatectomy but it is thought to increase the risk of short-term complications including postoperative pancreatic fistula (POPF). METHODS: International multicenter retrospective cohort study including patients from 51 centers in 19 countries (2010-2021). Primary endpoint was major morbidity. Secondary endpoints included POPF grade B/C, endocrine dysfunction, and the use of pancreatic enzymes. Two risk model were designed for major morbidity and endocrine dysfunction utilizing multivariable logistic regression and internal and external validation. RESULTS: 838 patients after CP were included (301 (36%) minimally invasive) and major morbidity occurred in 248 (30%) patients, POPF B/C in 365 (44%), and 30-day mortality in 4 (1%). Endocrine dysfunction in 91 patients (11%) and use of pancreatic enzymes in 108 (12%). The risk model for major morbidity included male sex, age, BMI, and ASA score≥3. The model performed acceptable with an area under curve (AUC) of 0.72(CI:0.68-0.76). The risk model for endocrine dysfunction included higher BMI and male sex and performed well (AUC:0.83 (CI:0.77-0.89)). CONCLUSIONS: The proposed risk models help in tailoring the use of CP in patients with symptomatic benign and premalignant lesions in the body and neck of the pancreas and are readily available via www.pancreascalculator.com.

Surgical complications requiring late surgical revisions after pancreatoduodenectomy increase postoperative morbidity and mortality.

BACKGROUND: Pancreatoduodenectomies are complex surgical procedures with considerable postoperative morbidity and mortality. Here, we describe complications and outcomes in patients requiring surgical revisions following pancreatoduodenectomy. METHODS: A total of 1048 patients undergoing a pancreatoduodenectomy at our institution between 2002 and 2019 were analyzed retrospectively. All patients with surgical revisions were included. Revisions were divided into early and late using a cut-off of 5 days after the first surgery. Statistical significance was examined by using chi-square tests and Fisher's exact tests. Survival analysis was performed using Kaplan-Meier curves and log-rank tests. RESULTS: A total of 150 patients with at least 1 surgical revision after pancreatoduodenectomy were included. Notably, 64 patients had a revision during the first 5 days and were classified as early revision. Compared with the 86 patients with late revisions, we found no differences concerning wound infections, delayed gastric emptying, or acute kidney failure. After late revisions, we found significantly more cases of sepsis (31.4% late versus 15.6% early, p = 0.020) and reintubation due to respiratory failure (33.7% versus 18.8%, p = 0.031). Postoperative mortality was significantly higher within the late revision group (23.2% versus 9.4%, p = 0.030). CONCLUSION: Arising complications after pancreatoduodenectomy should be addressed as early as possible as patients requiring late surgical revisions frequently developed septic complications and multiorgan failure.

Surgical pancreatic biopsies for cases with locally advanced pancreatic cancer with inconclusive histology after interventional biopsy.

Background: Histopathological confirmation of malignancy is mandatory in patients with unresectable pancreatic cancer before initiation of palliative chemotherapy. When interventional biopsy proves unsuccessful, laparoscopic or open surgical biopsies become necessary. Methods: 66 consecutive surgical biopsies of the pancreas performed at a single institution between 01/2010 and 04/2020 were analyzed retrospectively. We analyzed sensitivity of histopathological confirmation of malignancy as well as complication rates of laparoscopic and open surgical biopsies in patients with suspected advanced pancreatic cancer after unsuccessful interventional biopsies. Results: 8 complications were observed in 46 patients requiring only a pancreatic biopsy (17.4 %) while in 13 of 20 patients complications were observed when additional procedures were necessary (65 %). Major complications CD ≥ III were observed in the "biopsy +/- port" group in 4 of 46 patients and in the "biopsy + additional procedure" cohort in 9 of 20 patients (8.7 vs. 45 %, p < 0.001). Despite the trend to reduced perioperative complications in laparoscopic biopsies, the reduction did not reach statistical significance when compared to open resections (11.1 vs. 26.3 %, p = 0.18). Surgical pancreatic biopsies reached a sensitivity regarding the correct definite histopathological result of 90.32 %, specificity was 100 %. Conclusion: Both laparoscopic and open biopsies can be performed at acceptable complication rates CD ≥ III of 8.7 % and present a valuable option after failure of image-guided techniques for biopsy. Additional operative measures in locally advanced pancreatic carcinoma ought to be critically reflected due to a substantially higher complication rate CD ≥ III of 45 %. Key message: Laparoscopic and open surgical biopsies in patients with unresectable pancreatic cancer demonstrate a high diagnostic sensitivity at acceptable complication rates. This finding is important because it provides further support for surgical biopsies to avoid delay before initiation of palliative therapy.

BRAFΔß3-αC in-frame deletion mutants differ in their dimerization propensity, HSP90 dependence, and druggability.

In-frame BRAF exon 12 deletions are increasingly identified in various tumor types. The resultant BRAFΔß3-αC oncoproteins usually lack five amino acids in the ß3-αC helix linker and sometimes contain de novo insertions. The dimerization status of BRAFΔß3-αC oncoproteins, their precise pathomechanism, and their direct druggability by RAF inhibitors (RAFi) has been under debate. Here, we functionally characterize BRAFΔLNVTAP>F and two novel mutants, BRAFdelinsFS and BRAFΔLNVT>F, and compare them with other BRAFΔß3-αC oncoproteins. We show that BRAFΔß3-αC oncoproteins not only form stable homodimers and large multiprotein complexes but also require dimerization. Nevertheless, details matter as aromatic amino acids at the deletion junction of some BRAFΔß3-αC oncoproteins, e.g., BRAFΔLNVTAP>F, increase their stability and dimerization propensity while conferring resistance to monomer-favoring RAFi such as dabrafenib or HSP 90/CDC37 inhibition. In contrast, dimer-favoring inhibitors such as naporafenib inhibit all BRAFΔß3-αC mutants in cell lines and patient-derived organoids, suggesting that tumors driven by such oncoproteins are vulnerable to these compounds.

Immune changes induced by periampullary adenocarcinoma are reversed after tumor resection and modulate the postoperative survival.

BACKGROUND: Tumor growth encompasses multiple immunologic processes leading to impaired immunity. Regarding cancer surgery, the perioperative period is characterized by additional immunosuppression, which may contribute to poorer outcomes. In this exploratory study, we assessed plasma parameters characterizing the perioperative immunity with a particular focus on their prognostic value. PATIENTS AND METHODS: 31 patients undergoing pancreatoduodenectomy were enrolled (adenocarcinoma of the pancreatic head and its periampullary region: n = 24, benign pancreatic diseases n = 7). Abundance and function of circulating immune cells and the plasma protein expression were analyzed in blood samples taken pre- and postoperatively using flow cytometry, ELISA and Proximity Extension Assay. RESULTS: Prior to surgery, an increased population of Tregs, a lower level of intermediate monocytes, a decreased proportion of activated T-cells, and a reduced response of T-cells to stimulation in vitro were associated with cancer. On the first postoperative day, both groups showed similar dynamics. The preoperative alterations did not persist six weeks postoperatively. Moreover, several preoperative parameters correlated with postoperative survival. CONCLUSION: Our data suggests systemic immunologic changes in adenocarcinoma patients, which are reversible six weeks after tumor resection. Additionally, the preoperative immune status affects postoperative survival. In summary, our results implicate prognostic and therapeutic potential, justifying further trials on the perioperative tumor immunity to maximize the benefit of surgical tumor therapy.

Clinical characteristics and long-term outcomes following pancreatic injury - An international multicenter cohort study.

Background: Trauma to the pancreas is rare but associated with significant morbidity. Currently available management guidelines are based on low-quality evidence and data on long-term outcomes is lacking. This study aimed to evaluate clinical characteristics and patient-reported long-term outcomes for pancreatic injury. Methods: A retrospective cohort study evaluating treatment for pancreatic injury in 11 centers across 5 European nations over >10 years was performed. Data relating to pancreatic injury and treatment were collected from hospital records. Patients reported quality of life (QoL), changes to employment and new or ongoing therapy due to index injury. Results: In all, 165 patients were included. The majority were male (70.9%), median age was 27 years (range: 6-93) and mechanism of injury predominantly blunt (87.9%). A quarter of cases were treated conservatively; higher injury severity score (ISS) and American Association for the Surgery of Trauma (AAST) pancreatic injury scores increased the likelihood for surgical, endoscopic and/or radiologic intervention. Isolated, blunt pancreatic injury was associated with younger age and pancreatic duct involvement; this cohort appeared to benefit from non-operative management. In the long term (median follow-up 93; range 8-214 months), exocrine and endocrine pancreatic insufficiency were reported by 9.3% of respondents. Long-term analgesic use also affected 9.3% of respondents, with many reported quality of life problems (QoL) potentially attributable to side-effects of opiate therapy. Overall, impaired QoL correlated with higher ISS scores, surgical therapy and opioid analgesia on discharge. Conclusions: Pancreatic trauma is rare but can lead to substantial short- and long-term morbidity. Near complete recovery of QoL indicators and pancreatic function can occur despite significant injury, especially in isolated, blunt pancreatic injury managed conservatively and when early weaning off opiate analgesia is achieved.

Biomarkers in Liquid Biopsies for Prediction of Early Liver Metastases in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid malignancies with poor survival rates. Only 20% of the patients are eligible for R0-surgical resection, presenting with early relapses, mainly in the liver. PDAC patients with hepatic metastases have a worse outcome compared to patients with metastases at other sites. Early detection of hepatic spread bears the potential to improve patient outcomes. Thus, this study sought for serum-based perioperative biomarkers allowing discrimination of early (EHMS ≤ 12 months) and late hepatic metastatic spread (LHMS > 12 months). Serum samples from 83 resectable PDAC patients were divided into EHMS and LHMS and analyzed for levels of inflammatory mediators by LEGENDplexTM, which was validated and extended by Olink® analysis. CA19-9 serum levels served as control. Results were correlated with clinicopathological data. While serum CA19-9 levels were comparable, Olink® analysis confirmed distinct differences between both groups. It revealed significantly elevated levels of factors involved in chemotaxis and migration of immune cells, immune activity, and cell growth in serum of LHMS-patients. Overall, Olink® analysis identified a comprehensive biomarker panel in serum of PDAC patients that could provide the basis for predicting LHMS. However, further studies with larger cohorts are required for its clinical translation.

Stent-Associated Infectious Complications After Pancreatoduodenectomies Can Be Prevented by Perioperative Antibiotic Therapy: An Analysis of Single-Center Standards.

OBJECTIVES: Perioperative morbidity after pancreatoduodenectomies is still high. One potentially responsible factor is the insertion of bile duct stents before surgery. In our single-center study, we evaluated the influence of preoperative bile duct stenting combined with perioperative antibiotic therapy versus primary surgery in carcinoma patients. METHODS: Clinical data of 973 patients undergoing pancreatoduodenectomy at the University Hospital Freiburg from 2002 to 2018 were explored retrospectively. Postoperative pancreatic fistula, delayed gastric emptying (DGE), and postpancreatectomy hemorrhage (PPH) were graded by current international definitions. Patients with pancreatic ductal adenocarcinoma or periampullary carcinoma were included. RESULTS: We included 634 patients of whom 372 (58.7%) were treated with preoperative bile duct stenting. No difference concerning postoperative pancreatic fistula was observed (P = 0.479). We found more wound infections (stent 18.4%, no stent 11.1%, P = 0.008) but a significantly lower rate of PPH and DGE in stented patients (PPH 7.5% vs 11.9%, P = 0.044; DGE 16.5% vs 22.5%, P = 0.039). Surprisingly, intra-abdominal abscesses were reduced in stented patients (9.4% vs 15.0%, P = 0.022), just as insufficiencies of the biliodigestive anastomosis (P = 0.021). CONCLUSIONS: Perioperative antibiotic therapy seems to reduce the risk for severe intra-abdominal infectious complications in stent-bearing patients.

Rapid Capture of Cancer Extracellular Vesicles by Lipid Patch Microarrays.

Extracellular vesicles (EVs) contain various bioactive molecules such as DNA, RNA, and proteins, and play a key role in the regulation of cancer progression. Furthermore, cancer-associated EVs carry specific biomarkers and can be used in liquid biopsy for cancer detection. However, it is still technically challenging and time consuming to detect or isolate cancer-associated EVs from complex biofluids (e.g., blood). Here, a novel EV-capture strategy based on dip-pen nanolithography generated microarrays of supported lipid membranes is presented. These arrays carry specific antibodies recognizing EV- and cancer-specific surface biomarkers, enabling highly selective and efficient capture. Importantly, it is shown that the nucleic acid cargo of captured EVs is retained on the lipid array, providing the potential for downstream analysis. Finally, the feasibility of EV capture from patient sera is demonstrated. The demonstrated platform offers rapid capture, high specificity, and sensitivity, with only a small need in analyte volume and without additional purification steps. The platform is applied in context of cancer-associated EVs, but it can easily be adapted to other diagnostic EV targets by use of corresponding antibodies.

Immunological effects of hybrid minimally invasive versus conventional open pancreatoduodenectomy - A single center cohort study.

BACKGROUND: Minimally invasive surgery is a field of rapid development. Evidence from randomized controlled trials in visceral surgery however still falls short of attesting unequivocal superiority to laparoscopic procedures over conventional open approaches with regard to postoperative outcome. The aim of this study was to explore the perioperative immune status of patients undergoing hybrid minimally invasive or conventional open pancreatoduodenectomy in a prospective cohort study. MATERIAL AND METHODS: Subtyping, quantification and functional analysis of circulating immune cells and determination of cytokine-levels in blood samples from patients receiving either hybrid minimally invasive (laPD) or conventional open pancreatoduodenectomy (oPD) was performed. Samples were taken from 29 patients (laPD: n = 14, oPD: n = 15) prior, during and up to six weeks after surgery. Cells were analyzed by flow cytometry, cytokines/chemokines were measured by proximity extension and enzyme-linked immunoassays. RESULTS: Open surgery induced higher levels of circulating inflammatory CD14++CD16+ intermediate monocytes. In contrast, hybrid minimally invasive resection was accompanied by increased numbers of circulating regulatory CD4+CD25+CD127low T-cells and by a reduced response of peripheral blood CD3+CD4+ T-cell populations to superantigen stimulation. Yet, rates of postoperative morbidity and infectious complications were similar. CONCLUSIONS: In summary, the results of this exploratory study may suggest a more balanced postoperative inflammatory response and a better-preserved immune regulation after hybrid minimally invasive pancreatoduodenectomy when compared to open surgery. Whether these results may translate to or be harnessed for improved patient outcome needs to be determined by future studies including larger cohorts and fully laparoscopic or robotic procedures.

Plasma biomarkers for prediction of early tumor recurrence after resection of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a disease with a very unfavorable prognosis. Surgical resection represents the only potentially curative treatment option, but recurrence after complete resection is almost certain. In an exploratory attempt we here aimed at identifying preoperative plasma protein biomarkers with the potential to predict early recurrence after resection of PDAC. Peripheral blood samples from 14 PDAC patients divided into three groups according to their time to tumor recurrence after curatively intended resection (early: < 6 months, medium: 6-12 months, late: > 12 months) underwent targeted proteome analysis. Proteins most strongly discriminating early and late recurrence were then examined in a number of established PDAC cell lines and their culture supernatants. Finally, PDAC organoid lines from primary tumors of patients with early and late recurrence were analyzed for confirmation and validation of results. In total, 23 proteins showed differential abundance in perioperative plasma from PDAC patients with early recurrence when compared to patients with late recurrence. Following confirmation of expression on a transcriptional and translational level in PDAC cell lines we further focused on three upregulated (MAEA, NT5E, AZU1) and two downregulated proteins (ATP6AP2, MICA). Increased expression of NT5E was confirmed in a subset of PDAC organoid cultures from tumors with early recurrence. MICA expression was heterogeneous and ATP6AP2 levels were very similar in both organoids from early and late recurrent tumors. Most strikingly, we observed high MAEA expression in all tested PDAC (n = 7) compared to a non-cancer ductal organoid line. MAEA also demonstrated potential to discriminate early recurrence from late recurrence PDAC organoids. Our study suggests that identification of plasma protein biomarkers released by tumor cells may be feasible and of value to predict the clinical course of patients. Prediction of recurrence dynamics would help to stratify up-front resectable PDAC patients for neoadjuvant chemotherapy approaches in an individualized fashion. Here, MAEA and NT5E were the most promising candidates for further evaluation.

Longitudinal analysis of cell-free mutated KRAS and CA 19-9 predicts survival following curative resection of pancreatic cancer.

BACKGROUND: Novel biomarkers and molecular monitoring tools hold potential to improve outcome for patients following resection of pancreatic ductal adenocarcinoma (PDAC). We hypothesized that the combined longitudinal analysis of mutated cell-free plasma KRAS (cfKRASmut) and CA 19-9 during adjuvant treatment and follow-up might more accurately predict disease course than hitherto available parameters. METHODS: Between 07/2015 and 10/2018, we collected 134 plasma samples from 25 patients after R0/R1-resection of PDAC during adjuvant chemotherapy and post-treatment surveillance at our institution. Highly sensitive discriminatory multi-target ddPCR assays were employed to screen plasma samples for cfKRASmut. cfKRASmut and CA 19-9 dynamics were correlated with recurrence-free survival (RFS) and overall survival (OS). Patients were followed-up until 01/2020. RESULTS: Out of 25 enrolled patients, 76% had undergone R0 resection and 48% of resected PDACs were pN0. 17/25 (68%) of patients underwent adjuvant chemotherapy. Median follow-up was 22.0 months, with 19 out of 25 (76%) patients relapsing during study period. Median RFS was 10.0 months, median OS was 22.0 months. Out of clinicopathologic variables, only postoperative CA 19-9 levels and administration of adjuvant chemotherapy correlated with survival endpoints. cfKRASmut. was detected in 12/25 (48%) of patients, and detection of high levels inversely correlated with survival endpoint. Integration of cfKRASmut and CA 19-9 levels outperformed either individual marker. cfKRASmut outperformed CA 19-9 as dynamic marker since increase during adjuvant chemotherapy and follow-up was highly predictive of early relapse and poor OS. CONCLUSIONS: Integrated analysis of cfKRASmut and CA 19-9 levels is a promising approach for molecular monitoring of patients following resection of PDAC. Larger prospective studies are needed to further develop this approach and dissect each marker's specific potential.

Updated Alternative Fistula Risk Score (ua-FRS) to Include Minimally Invasive Pancreatoduodenectomy: Pan-European Validation.

OBJECTIVE: The aim of the study was to validate and optimize the alternative Fistula Risk Score (a-FRS) for patients undergoing minimally invasive pancreatoduodenectomy (MIPD) in a large pan-European cohort. BACKGROUND: MIPD may be associated with an increased risk of postoperative pancreatic fistula (POPF). The a-FRS could allow for risk-adjusted comparisons in research and improve preventive strategies for high-risk patients. The a-FRS, however, has not yet been validated specifically for laparoscopic, robot-assisted, and hybrid MIPD. METHODS: A validation study was performed in a pan-European cohort of 952 consecutive patients undergoing MIPD (543 laparoscopic, 258 robot-assisted, 151 hybrid) in 26 centers from 7 countries between 2007 and 2017. The primary outcome was POPF (International Study Group on Pancreatic Surgery grade B/C). Model performance was assessed using the area under the receiver operating curve (AUC; discrimination) and calibration plots. Validation included univariable screening for clinical variables that could improve performance. RESULTS: Overall, 202 of 952 patients (21%) developed POPF after MIPD. Before adjustment, the original a-FRS performed moderately (AUC 0.68) and calibration was inadequate with systematic underestimation of the POPF risk. Single-row pancreatojejunostomy (odds ratio 4.6, 95 confidence interval [CI] 2.8-7.6) and male sex (odds ratio 1.9, 95 CI 1.4-2.7) were identified as important risk factors for POPF in MIPD. The updated a-FRS, consisting of body mass index, pancreatic texture, duct size, and male sex, showed good discrimination (AUC 0.75, 95 CI 0.71-0.79) and adequate calibration. Performance was adequate for laparoscopic, robot-assisted, and hybrid MIPD and open pancreatoduodenectomy. CONCLUSIONS: The updated a-FRS (www.pancreascalculator.com) now includes male sex as a risk factor and is validated for both MIPD and open pancreatoduodenectomy. The increased risk of POPF in laparoscopic MIPD was associated with single-row pancreatojejunostomy, which should therefore be discouraged.

Pancreatic Inflammation and Proenzyme Activation Are Associated With Clinically Relevant Postoperative Pancreatic Fistulas After Pancreas Resection.

OBJECTIVE: We investigated the activation of pancreatic proenzymes and signs of peripancreatic inflammation in patients with clinically relevant postoperative pancreatic fistulas (POPFs). SUMMARY BACKGROUND DATA: An increase of systemic amylase concentration was associated with POPFs. This suggested parallels in the pathomechanisms between the development of POPFs and pancreatitis. METHODS: Trypsinogen, procathepsin B, and IL-6 concentrations as well as cathepsin B, myeloperoxidase and trypsin activities were determined throughout the first 7 postoperative days in drain fluids of 128 consecutive patients after pancreas resection. Histology and immunohistochemistry were performed in pancreatic specimens after total pancreatectomy due to complications and after placing experimental pancreatic sutures in the pancreatic tail of C57/Bl6 mice. RESULTS: Trypsin activity, cathepsin B activity and myeloperoxidase activity on the first postoperative day were elevated and predictive for clinically relevant pancreatic fistulas. Drain fluid stabilized trypsin activity and prevented the activation of the cascade of digestive enzymes. Leukocytes were the source of cathepsin B in drain fluid. Findings differed between fistulas after distal pancreatectomy and pancreatoduodenectomy. Immunohistochemistry of the pancreatic remnant revealed an inflammatory infiltrate expressing cathepsin B, independent of the presence of pancreatic fistulas. The infiltrate could be reproduced experimentally by sutures placed in the pancreatic tail of C57/Bl6 mice. CONCLUSIONS: Trypsinogen activation, increased cathepsin B activity and inflammation around the pancreato-enteric anastomosis on post operative day 1 are associated with subsequent clinically relevant POPFs after pancreatoduodenectomy. The parenchymal damage seems to be induced by placing sutures in the pancreatic parenchyma during pancreatic surgery.

Metabolic Profiling of Early and Late Recurrent Pancreatic Ductal Adenocarcinoma Using Patient-Derived Organoid Cultures.

Pancreatic ductal adenocarcinoma (PDAC) is associated with high mortality and will become the second most common cause of cancer-associated mortality by 2030. The poor prognosis arises from a lack of sensitive biomarkers, limited therapeutic options, and the astonishingly high recurrence rate after surgery of 60-80%. The factors driving this recurrence, however, remain enigmatic. Therefore, we generated patient-derived organoids (PDOs) from early- and late-recurrent PDAC patients. Cellular identity of PDOs was confirmed by qPCR, ddPCR, and IHC analyses. This is the first study investigating the metabolism in PDOs of different, clinically significant PDAC entities by untargeted GC/MS profiling. Partial least square discriminant analysis unveiled global alterations between the two sample groups. We identified nine metabolites to be increased in early recurrent PDOs in comparison to late recurrent PDOs. More than four-times increased were fumarate, malate, glutamate, aspartate, and glutamine. Hence, α-keto acids were elevated in PDO-conditioned medium derived from early recurrent patients. We therefore speculate that an increased anaplerotic metabolism fuels the Krebs-cycle and a corresponding higher accessibility to energy fastens the recurrence in PDAC patients. Therein, a therapeutic intervention could delay PDAC recurrence and prolong survival of affected patients or could serve as biomarker to predict recurrence in the future.

Metabolic Adaptation during nab-Paclitaxel Resistance in Pancreatic Cancer Cell Lines.

Pancreatic ductal adenocarcinoma (PDAC) correlates with high mortality and is about to become one of the major reasons for cancer-related mortality in the next decades. One reason for that high mortality is the limited availability of effective chemotherapy as well as the intrinsic or acquired resistance against it. Here, we report the impact of nab-paclitaxel on the cellular metabolome of PDAC cell lines. After establishment of nab-paclitaxel resistant cell lines, comparison of parental and resistant PDAC cell lines by metabolomics and biochemical assessments revealed altered metabolism, enhanced viability and reduced apoptosis. The results unveiled that acute nab-paclitaxel treatment affected primary metabolism to a minor extent. However, acquisition of resistance led to altered metabolites in both cell lines tested. Specifically, aspartic acid and carbamoyl-aspartic acid were differentially abundant, which might indicate an increased de novo pyrimidine synthesis. This pathway has already shown a similar behavior in other cancerous entities and thus might serve in the future as vulnerable target fighting resistance acquisition occurring in common malignancies.

Development and Clinical Validation of Discriminatory Multitarget Digital Droplet PCR Assays for the Detection of Hot Spot KRAS and NRAS Mutations in Cell-Free DNA.

Detection and quantification of tumor-derived KRAS and NRAS mutations in plasma cell-free DNA (cfDNA) holds great potential for cancer diagnostics and treatment response monitoring. Because of high sensitivity, specificity, robustness, and affordability, digital droplet PCR (ddPCR) is ideally suited for this application but requires discriminatory multiplexing when used as screening assay. We therefore designed, optimized, and clinically validated mutation-specific locked nucleic acid-based ddPCR assays for 14 commonly occurring KRAS and NRAS mutations and assembled these assays into seven discriminatory multitarget screening assays covering two to six single-nucleotide variants each. Limit of detection, limit of blank, and interassay accuracy were determined. Assay performance and suitability for screening in cfDNA were validated with plasma samples from a clinically fully characterized cohort of pancreatic cancer patients and healthy controls. Limits of detection for single-target assays were between 0.0015% and 0.069% variant allele fraction, and between 0.022% and 0.16% for multitarget assays. Dilution linearity and interassay accuracy were excellent throughout (r2 > 0.99). Multitarget assay screening of cfDNA extracted from pancreatic cancer patients with unknown KRAS mutational status correctly identified single-nucleotide variants in 45 of 45 (100%) of tumor-derived cell-free DNA-positive samples. In summary, we herein present and clinically validate generic single-target and discriminatory multitarget ddPCR assays for KRAS and NRAS hot spot mutations with broad applicability for clinical and translational research.