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.

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.

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.

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.

Outcomes After Minimally-invasive Versus Open Pancreatoduodenectomy: A Pan-European Propensity Score Matched Study.

OBJECTIVE: To assess short-term outcomes after minimally invasive (laparoscopic, robot-assisted, and hybrid) pancreatoduodenectomy (MIPD) versus open pancreatoduodenectomy (OPD) among European centers. BACKGROUND: Current evidence on MIPD is based on national registries or single expert centers. International, matched studies comparing outcomes for MIPD and OPD are lacking. METHODS: Retrospective propensity score matched study comparing MIPD in 14 centers (7 countries) performing ≥10 MIPDs annually (2012-2017) versus OPD in 53 German/Dutch surgical registry centers performing ≥10 OPDs annually (2014-2017). Primary outcome was 30-day major morbidity (Clavien-Dindo ≥3). RESULTS: Of 4220 patients, 729/730 MIPDs (412 laparoscopic, 184 robot-assisted, and 130 hybrid) were matched to 729 OPDs. Median annual case-volume was 19 MIPDs (interquartile range, IQR 13-22), including the first MIPDs performed in 10/14 centers, and 31 OPDs (IQR 21-38). Major morbidity (28% vs 30%, P = 0.526), mortality (4.0% vs 3.3%, P = 0.576), percutaneous drainage (12% vs 12%, P = 0.809), reoperation (11% vs 13%, P = 0.329), and hospital stay (mean 17 vs 17 days, P > 0.99) were comparable between MIPD and OPD. Grade-B/C postoperative pancreatic fistula (POPF) (23% vs 13%, P < 0.001) occurred more frequently after MIPD. Single-row pancreatojejunostomy was associated with POPF in MIPD (odds ratio, OR 2.95, P < 0.001), but not in OPD. Laparoscopic, robot-assisted, and hybrid MIPD had comparable major morbidity (27% vs 27% vs 35%), POPF (24% vs 19% vs 25%), and mortality (2.9% vs 5.2% vs 5.4%), with a fewer conversions in robot-assisted- versus laparoscopic MIPD (5% vs 26%, P < 0.001). CONCLUSIONS: In the early experience of 14 European centers performing ≥10 MIPDs annually, no differences were found in major morbidity, mortality, and hospital stay between MIPD and OPD. The high rates of POPF and conversion, and the lack of superior outcomes (ie, hospital stay, morbidity) could indicate that more experience and higher annual MIPD volumes are needed.

Retroperitoneal soft tissue sarcoma: low-dose neoadjuvant radiation therapy followed by surgery with or without intraoperative radiotherapy and adjuvant radiation therapy.

BACKGROUND: We describe the clinical history, outcome, and toxicity of five patients with high-grade retroperitoneal soft tissue sarcoma (RSTS) who were treated with neoadjuvant low-dose radiotherapy (RT) followed by resection with or without intraoperative radiotherapy (IORT), followed by adjuvant RT. We aim to provide additional evidence for the various treatment options that exist for this rare tumor entity. METHODS: Most patients presented with mild abdominal symptoms. Diagnosis was confirmed by biopsy. Additional imaging was done by sonography, magnetic resonance imaging (MRI), and/or positron emission tomography (PET)/computed tomography (CT). All patients were treated with neoadjuvant RT of 19.8 Gy in 1.8-Gy fractions followed by resection and postoperative RT up to 45 Gy with a median interval between resection and start of postoperative RT of 5 weeks. Two patients received additional IORT. Median follow-up was 61 months. RESULTS: One patient developed a local recurrence that was diagnosed 30 months after the start of the first therapy. He was treated with a salvage resection and had no evidence of disease at the last follow-up. Another patient developed a right-sided RSTS on the contralateral side from the primary radiation field with pelvic bone infiltration 56 months after the start of RT. He was treated again by RT and resection and was without evidence of disease at last follow-up. Radiotherapy was well tolerated without major toxicity. CONCLUSION: The treatment of RSTS by low-dose neoadjuvant RT, resection with IORT and adjuvant RT seems to be a feasible and effective treatment approach. Further studies comparing neoadjuvant with adjuvant RT are necessary to find the best treatment option.

Unraveling altered RNA metabolism in pancreatic cancer cells by liquid-chromatography coupling to ion mobility mass spectrometry.

Ion mobility coupling to mass spectrometry facilitates enhanced identification certitude. Further coupling to liquid chromatography results in multi-dimensional analytical methods, especially suitable for complex matrices with structurally similar compounds. Modified nucleosides represent a large group of very similar members linked to aberrant proliferation. Besides basal production under physiological conditions, they are increasingly excreted by transformed cells and subsequently discussed as putative biomarkers for various cancer types. Here, we report a method for modified nucleosides covering 37 species. We determined collisional cross-sections with high reproducibility from pure analytical standards. For sample purification, we applied an optimized phenylboronic acid solid-phase extraction on media obtained from four different pancreatic cancer cell lines. Our analysis could discriminate different subtypes of pancreatic cancer cell lines. Importantly, they could clearly be separated from a pancreatic control cell line as well as blank medium. m1A, m27G, and Asm were the most important features discriminating cancer cell lines derived from well-differentiated and poorly differentiated cancers. Eventually, we suggest the analytical method reported here for future tumor-marker identification studies. Graphical abstract.

Adjuvant chemotherapy after surgery for pancreatic ductal adenocarcinoma: retrospective real-life data.

BACKGROUND: The recommendation for postoperative chemotherapy in pancreatic ductal adenocarcinoma (PDAC) is based on prospective randomized trials. However, patients included in clinical trials do not often reflect the overall patient population treated in clinical practice. MATERIALS AND METHODS: A retrospective review of all patients undergoing pancreas resection for PDAC between 2001 and 2013 was performed. Follow-up data from oncologists, general practitioners, or hospital patient files were available for 92% of patients. RESULTS: A total of 251 patients were included in our analysis. Chemotherapy was recommended for 223 patients, but 86 patients did not follow the recommendation. The application of the recommended chemotherapy, consisting of 6 cycles of gemcitabine, was only applied to 45 patients. Forty patients received the recommended number of cycles with dose reduction or prolonged intervals between cycles, and adjuvant chemotherapy was terminated prior to the intended completion of all 6 cycles in 54 patients. Survival of patients after adjuvant chemotherapy was increased compared to that of patients without chemotherapy (with recurrence 25.6 vs. 14.3 months, p = 0.001, and without recurrence 27.4 vs. 14.3 months, p <  0.001). Terminating chemotherapy prior to completion (p = 0.009) as well as a lower number of chemotherapy cycles (p = 0.026) was associated with a decreased survival. CONCLUSION: Adjuvant chemotherapy improves overall and disease-free survival after curative pancreatic resection, but only a small fraction of patients completes the recommended 6 cycles of adjuvant chemotherapy. Our data indicates that performance status of patients after pancreas resections for PDAC requires not only highly biologically active but also well-tolerated adjuvant chemotherapy regimens.

Prognostic relevance of preoperative bilirubin-adjusted serum carbohydrate antigen 19-9 in a multicenter subset analysis of 179 patients with distal cholangiocarcinoma.

BACKGROUND: Distal cholangiocarcinoma (DCC) is a rare malignancy and validated prognostic markers remain scarce. We aimed to evaluate the role of serum CA19-9 as a potential biomarker in DCC. METHODS: Patients operated for DCC at 6 high-volume surgical centers from 1994 to 2015 were identified from prospectively maintained databases. Patient baseline characteristics, surgical and histopathological parameters, as well as overall survival after resection were assessed for correlation with preoperative bilirubin-adjusted serum carbohydrate antigen 19-9 (CA19-9). Preoperative CA19-9 to bilirubin ratio (CA19-9/BR) was classified as elevated (≥ 25 U/ml/mg/dl) according to the upper serum normal values of CA19-9 (37 U/ml) and bilirubin (1.5 mg/dl) giving a cut-off at ≥ 25 U/ml/mg/dl. RESULTS: In total 179 patients underwent resection for DCC during the study period. High preoperative CA19-9/BR was associated with advanced age and regional lymph node metastases. Median overall survival after resection was 27 months. Elevated preoperative serum CA19-9/bilirubin ratio (HR 1.6, p = 0.025), T3/4 stage (HR 1.8, p = 0.022), distant metastasis (HR 2.5, p = 0.007), tumor grade (HR 1.9, p = 0.001) and R status (HR 1.7, p = 0.023) were identified as independent negative prognostic factors following multivariable analysis. CONCLUSION: Elevated preoperative bilirubin-adjusted serum CA19-9 correlates with regional lymph node metastases and constitutes a negative independent prognostic factor after resection of DCC.

Partial pancreatoduodenectomy versus duodenum-preserving pancreatic head resection in chronic pancreatitis: the multicentre, randomised, controlled, double-blind ChroPac trial.

BACKGROUND: There is substantial uncertainty regarding the optimal surgical treatment for chronic pancreatitis. Short-term outcomes have been found to be better after duodenum-preserving pancreatic head resection (DPPHR) than after partial pancreatoduodenectomy. Therefore, we designed the multicentre ChroPac trial to investigate the long-term outcomes of patients with chronic pancreatitis within 24 months after surgery. METHODS: This randomised, controlled, double-blind, parallel-group, superiority trial was done in 18 hospitals across Europe. Patients with chronic pancreatitis who were planned for elective surgical treatment were randomly assigned to DPPHR or partial pancreatoduodenectomy with a central web-based randomisation tool. The primary endpoint was mean quality of life within 24 months after surgery, measured with the physical functioning scale of the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire. Primary analysis included all patients who underwent one of the assigned procedures; safety analysis included all patients who underwent surgical intervention (categorised into groups as treated). Patients and outcome assessors were masked to group assignment. The trial was registered, ISRCTN38973832. Recruitment was completed on Sept 3, 2013. FINDINGS: Between Sept 10, 2009, and Sept 3, 2013, 250 patients were randomly assigned to DPPHR (n=125) or partial pancreatoduodenectomy (n=125), of whom 226 patients (115 in the DPPHR group and 111 in the partial pancreatoduodenectomy group) were analysed. No difference in quality of life was seen between the groups within 24 months after surgery (75·3 [SD 16·4] for partial pancreatoduodenectomy vs 73·0 [16·4] for DPPHR; mean difference -2·3, 95% CI -6·6 to 2·0; p=0·284). The incidence and severity of serious adverse events did not differ between the groups. 70 (64%) of 109 patients in the DPPHR group and 61 (52%) of 117 patients in the partial pancreatoduodenectomy group had at least one serious adverse event, with the most common being reoperations (for reasons other than chronic pancreatitis), gastrointestinal problems, and other surgical morbidity. INTERPRETATION: No differences in quality of life after surgery for chronic pancreatitis were seen between the interventions. Results from single-centre trials showing superiority for DPPHR were not confirmed in the multicentre setting. FUNDING: German Research Foundation (DFG).

The predominance of a naive T helper cell subset in the immune response of experimental acute pancreatitis.

INTRODUCTION: In necrotizing acute pancreatitis (NAP), systemic inflammatory response syndrome (SIRS) and the compensatory anti-inflammatory response syndrome (CARS) decide overall outcome and mortality. In patients, low lymphocyte counts were found, but T-helper cells seemed to conversely increase. Our aim was to further categorize T-helper cells within the context of NAP induced SIRS and CARS. METHODS: NAP was induced by injection of sodium-taurocholate into the common bile duct of male BALB/c mice; sham treated animals received saline infusion. The animals were sacrificed at 6, 12, 24 and 48 h later. Lymphocytes from blood, liver and spleen were isolated and examined by flow cytometry. Staining was performed for CD4, CD8, CD19, CD45RB, CD25, CD69, and CD152. CD4+ cells were sorted for their CD45RB expression and sought for gene regulation associated to TH1/TH2 cells by quantitative RT-PCR. RESULTS: In NAP, CD4+ was solely increased in all compartments. CD8+ remained without substantial alterations. CD45RB showed significant expression in RBhigh in T-helper cells, confirmed by the CD45RBhigh/low ratio (Liver, 24 h: NAP 2.2, SHAM 0.6; p < 0.001). CD45RBhigh and -low cells were not associated to patterns of TH1/TH2 expression. In NAP, CCR4 expression was significantly decreased within RBhigh cells (fold change: 0.04, p < 0.05), while TLR6 showed significant overexpression (fold change: 2.36, p < 0.05). CONCLUSION: T-helper cells increase in NAP, leaning towards CD45RBhigh expression. They resemble naive T-cells, in which NAP leads to expression profiles associated with an innate immune response. This suggests new findings in immunological pathomechanisms of NAP.

Survival outcome and prognostic factors after pancreatoduodenectomy for distal bile duct carcinoma: a retrospective multicenter study.

PURPOSE: Pancreatoduodenectomy is the most common operative procedure performed for distal bile duct carcinoma. Data on outcome after surgery for this rare malignancy is scarce, especially from western countries. The purpose of this study is to explore the prognostic factors and outcome after pancreatoduodenectomy for distal bile duct carcinoma. METHODS: Patients receiving pancreatoduodenectomy for distal bile duct carcinoma were identified from institutional databases of five German and one Russian academic centers for pancreatic surgery. Univariable and multivariable general linear model, Kaplan-Meier method, and Cox regression were used to identify prognostic factors for postoperative mortality and overall survival. RESULTS: N = 228 patients operated from 1994 to 2015 were included. Reoperation (OR 5.38, 95%CI 1.51-19.22, p = 0.010), grade B/C postpancreatectomy hemorrhage (OR 3.73, 95%CI 1.13-12.35, p = 0.031), grade B/C postoperative pancreatic fistula (OR 4.29, 95%CI 1.25-14.72, p = 0.038), and advanced age (OR 4.00, 95%CI 1.12-14.03, p = 0.033) were independent risk factors for in-hospital mortality in multivariable analysis. Median survival was 29 months, 5-year survival 27%. Positive resection margin (HR 2.07, 95%CI 1.29-3.33, p = 0.003), high tumor grade (HR 1.71, 95%CI 1.13-2.58, p = 0.010), lymph node (HR 1.68, 95%CI 1.13-2.51, p = 0.011), and distant metastases (HR 2.70, 95%CI 1.21-5.58, p = 0.014), as well as severe non-fatal postoperative complications (HR 1.64, 95%CI 1.04-2.58, p = 0.033) were independent negative prognostic factors for survival in multivariable analysis. CONCLUSION: Distant metastases and positive resection margin are the strongest negative prognostic factors for survival after pancreatoduodenectomy for distal bile duct carcinoma; thus, surgery with curative intent is only warranted in patients with local disease, where R0 resection is feasible.

Histopathological tumor invasion of the mesenterico-portal vein is characterized by aggressive biology and stromal fibroblast activation.

BACKGROUND: Mesenterico-portal vein resection (PVR) during pancreatoduodenectomy for pancreatic head cancer was established in the 1990s and can be considered a routine procedure in specialized centers today. True histopathologic portal vein invasion is predictive of poor prognosis. The aim of this study was to examine the relationship between mesenterico-portal venous tumor infiltration (PVI) and features of aggressive tumor biology. METHODS: Patients receiving PVR for pancreatic ductal adenocarcinoma of the pancreatic head were identified from a prospectively maintained database. Immunohistochemical staining of tumor tissue was performed for the markers of epithelial-mesenchymal transition (EMT) E-Cadherin, Vimentin and beta-Catenin. Morphology of cancer-associated fibroblasts (CAFs) was assessed as inactive or activated. Statistical calculations were performed with MedCalc software. RESULTS: In total, 41 patients could be included. Median overall survival was 25 months. PVI was found in 17 patients (41%) and was significantly associated with loss of membranous E-Cadherin in tumor buds (p = 0.020), increased Vimentin expression (p = 0.03), activated CAF morphology (p = 0.046) and margin positive resection (p = 0.005). CONCLUSION: Our findings suggest that PVI is associated with aggressive tumor biology and disseminated growth less amenable to margin-negative resection.

Colon carcinogenesis in wild type and immune compromised mice after treatment with azoxymethane, and azoxymethane with dextran sodium sulfate.

The association between inflammation and the risk of colorectal cancer (CRC) is well documented in animal models and in humans, but the mechanistic role of inflammation in CRC is less well understood. To address this question, the induction of colon tumors was evaluated in (i) wild type (WT) and athymic BALB/c mice treated with the colon carcinogen azoxymethane (AOM) as a single agent, and (ii) in an inflammation model of colon cancer employing AOM and dextran sodium sulfate (DSS) in WT, athymic, TCRß(-/-) , TCRδ(-/-) and TCRß(-/-) TCRδ(-/-) C57Bl/6 mice. The athymic BALB/c mice treated with only AOM developed 90% fewer tumors than the WT mice. The difference in response was not due to metabolic activation of AOM or repair of DNA adducts. In the inflammation model using a standard sequential exposure to AOM followed by DSS treatment, the tumor incidence in WT mice was 58% with 7 adenomas and 6 adenocarcinomas. In contrast, the TCRß(-/-) , TCRδ(-/-) and TCRß(-/-) TCRδ(-/-) C57Bl/6 mice showed adenoma incidences of 10, 33, and 11%, respectively, and none of the immune compromised mice developed adenocarcinomas. When the DSS exposure was increased and the AOM lowered, no difference was observed between WT and TCRß(-/-) mice due to an increase in the incidence in the TCR null mice without concomitant increase in the WT mice. No tumors were observed in mice treated with AOM or DSS alone. © 2015 Wiley Periodicals, Inc.

Inducing a humoral immune response to pancreatic cancer antigen.

BACKGROUND: Patients with pancreatic carcinoma have a grim prognosis. Here, we examine the induction of an in vitro antibody response of human B cells to pancreatic carcinoma antigens. MATERIAL AND METHODS: Cells of five cultured pancreatic ductal adenocarcinoma lines were lysed and their plasma membrane fragments isolated in an aqueous two-phase-system. The plasma membrane fragments were then added to cultures of isolated peripheral blood mononuclear cells from healthy volunteers for 14 days to act as a tumor antigen. Also, we added combinations of IL-2, IL-4, IL-21, anti-CD40 mAb and varying protein concentrations of the plasma membrane fragments to these cultures. We then tested characteristics and binding of resulting IgG and IgM against aforementioned tumor plasma membrane fragments and their respective cells using ELISAs. RESULTS: The combination of IL-2, IL-4 and anti-CD40 mAb elicited IgM production showing significant binding (p<0.05) to plasma membrane fragments. PANC-1 antigen and the combination of IL-4, IL-21 and anti-CD40 mAb was able to produce a significant and specific IgG formation against PANC-1 plasma membrane fragments (p<0.05). Tumor antigen, interleukins and anti-CD40 mAb had a significant impact on the binding capacity of these antibodies (p<0.05). IgG binding pancreatic carcinoma cells was observed when the tumor antigen concentration was increased during stimulation (p<0.05). BxPC3 plasma membrane fragments showed inhibitory effects on IgG binding BxPC3 antigens (p<0.05). CONCLUSIONS: A human anti-tumor antibody formation can be induced in vitro using PANC-1 antigens and B cell stimulating agents. This response has the potential to generate antibodies specific to PANC-1 antigens. PRéCIS: The concept presented is novel and a promising approach to eliciting a specific B cell response to tumor antigen. The method may prove useful in understanding and developing anti-tumor immunity.

Prognostic factors after pancreatoduodenectomy with en bloc portal venous resection for pancreatic cancer.

PURPOSE: Pancreatoduodenectomy (PD) with superior mesenteric/portal venous resection (PVR) for pancreatic ductal adenocarcinoma (PDAC) is performed routinely in case of tumor adhesion to the superior mesenteric or portal vein. True histopathological portal vein invasion (PVI) is found in a subgroup of patients. Even though this procedure has become routine in most centers for pancreatic surgery, data on prognostic factors in this situation is limited. The aim of this study was to identify prognostic factors after PD with PVR for PDAC. METHODS: Retrospective analysis was performed on the basis of a prospectively maintained database, and paraffin-embedded formalin-fixed tissue slides stained for hematoxylin-eosin were re-evaluated by two independent pathologists. Statistical analysis was conducted using MedCalc software. RESULTS: From 2001 to 2012, 86 cases of PD with PVR for PDAC with long-term follow-up and sufficient tissue for re-assessment were identified. Histopathological re-review disclosed PVI in 39 resection specimens and adhesion without infiltration in 47. Overall median survival in all patients was 22 months. Patients with PVI versus no PVI showed comparable baseline demographic and standard histopathological parameters; however, PVI was associated with microscopic hemangiosis (p = 0.001) and positive margin status (p = 0.001). Median survival in patients with PVI was 14 months versus 25 months in patients without PVI (p = 0.042). Only lymph node ratio and PVI were independent predictors of survival after resection. CONCLUSION: The only independent factors influencing overall survival after PD with PVR for PDAC were lymph node ratio and PVI. PVI might indicate aggressive tumor biology, but the available data remains controversial.

The chemokine ligand CXCL16 is an indicator of bacterial infection in necrotizing pancreatitis.

OBJECTIVES: Current guidelines tell us that intervention in severe necrotizing pancreatitis ought to be performed as late as possible. However, when pancreatic necrosis becomes infected, the necrotic tissue needs to be removed. Unfortunately, bacterial infection can only be proven by invasive methods. METHODS: Necrotizing pancreatitis with sterile or infected necrosis was induced in mice. Mice serum samples were examined by antibody-based protein array. After identifying candidate proteins that showed strong regulation, the serum concentration of these proteins was examined by sandwich ELISA. Then, human serum samples were collected from patients with mild pancreatitis, severe pancreatitis with and without pancreatic necrosis and patients with microbiologically proven infection of pancreatic necrosis. These serum samples were then analyzed by sandwich ELISA. RESULTS: In mice 6 proteins were strongly up-regulated and were further investigated by ELISAs. Of these proteins, CXCL16 and TRANCE (RANKL) concentrations were analyzed in human serum samples. CXCL16 and TRANCE were increased in patients with pancreatic necrosis and abdominal infection. Receiver operated characteristics showed that CXCL16 was superior in predicting infected pancreatic necrosis when compared to C-reactive protein and TRANCE. CONCLUSIONS: Serum CXCL16 is increased in severe pancreatitis with infected pancreatic necrosis and identifies patients who benefit from surgical necrosectomy.

Organ-specific monocyte activation in necrotizing pancreatitis in mice.

BACKGROUND: Acute necrotizing pancreatitis (NAP) induces a systemic inflammatory response syndrome. We investigated the underlying changes of monocytes using different activation markers. MATERIALS AND METHODS: A retrograde injection of 2 mL/kg bodyweight of sodium taurocholate into the common bile duct of BALB/c mice induced NAP, whereas sham-operated animals (SOP) were treated with saline. After 6, 12, 24, and 48 h, histologic alterations, pancreatic enzymes, and interleukin 6 in serum, albumin, and myeloperoxidase (MPO) in bronchoalveolar lavage fluid were examined. Isolation of mononuclear cells from the blood, spleen, and liver and the subsequent determination of macrophages (F4/80) and their activation marker CD121b and MHCII (1Ad) were performed by fluorescence-activated cell sorting (FACS analyses). RESULTS: After pancreatitis induction, pancreatic enzymes (amylase: SOP 7008 U/L, NAP 37,044 U/L, P < 0.001) and histologic pancreatic damage (SOP 0.80 ± 1.92, NAP 19.6 ± 0.64, P < 0.001) developed instantly. Pulmonary vascular damage and MPO were detected between 6 and 12 h after onset (6 h albumin SOP 132.0 ± 12.0 µg/mL, NAP 267.2 ± 49.6 µg/mL; P < 0.05; MPO SOP 0.23 ± 0.20 ng/mL, NAP 11.29 ± 3.12 ng/mL, P < 0.01). Blood levels of interleukin 6 increased after 12-24 h (12 h SOP 584 ± 300 pg/mL; NAP 2169 ± 942 pg/mL, P < 0.05), whereas monocytes increased fourfold within 48 h (P < 0.05). Furthermore, pancreatitis increased the percentage of activated monocytes in the blood (6 h and/or 48 h: MHCII (1Ad) 2196%/5.65%; CD121b 51,654%/82,146%). Similar observations were made for monocytes from the liver and spleen. CONCLUSIONS: Although inflammatory mediators increased during 24 h after pancreatitis induction, monocyte activation lasted for at least 48 h. The latter is not limited to blood but also detected in isolated liver and spleen monocytes.

Retrospective analyses of trends in pancreatic surgery: indications, operative techniques, and postoperative outcome of 1,120 pancreatic resections.

BACKGROUND: Hospital volume, surgeons' experience, and adequate management of complications are factors that contribute to a better outcome after pancreatic resections. The aim of our study was to analyze trends in indications, surgical techniques, and postoperative outcome in more than 1,100 pancreatic resections. METHODS: One thousand one hundred twenty pancreatic resections were performed since 1994. The vast majority of operations were performed by three surgeons. Perioperative data were documented in a pancreatic database. For the purpose of our analysis, the study period was sub-classified into three periods (A 1994 to 2001/n = 363; B 2001 to 2006/n = 305; C since 2007 to 2012/n = 452). RESULTS: The median patient age increased from 51 (A) to 65 years (C; P < 0.001). Indications for surgery were pancreatic/periampullary cancer (49%), chronic pancreatitis (CP; 33%), and various other lesions (18%). About two thirds of the operations were pylorus-preserving pancreaticoduodenectomies. The frequency of mesenterico-portal vein resections increased from 8% (A) to 20% (C; P < 0.01). The overall mortality was 2.4% and comparable in all three periods (2.8%, 2.0%, 2.4%; P = 0.8). Overall complication rates increased from 42% (A) to 56% (C; P < 0.01). CONCLUSIONS: Mortality remained low despite a more aggressive surgical approach to pancreatic disease. An increased overall morbidity may be explained by more clinically relevant pancreatic fistulas and better documentation.

The prognostic influence of intrapancreatic tumor location on survival after resection of pancreatic ductal adenocarcinoma.

BACKGROUND: The prognosis of pancreatic ductal adenocarcinoma (PDAC) is worse when the tumor is located in the pancreatic body or tail, compared to being located in the pancreatic head. However, for localized, resectable tumors survival seems to be at least similar. METHODS: We analyzed and compared the outcome after pancreatoduodenectomy (PD) and distal pancreatectomy (DP) for PDAC at our institution. Clinical, pathological and survival data from patients undergoing pancreatic resection for PDAC 1994-2014 were explored retrospectively, accessing a prospective pancreatic database. Patients receiving primary total pancreatectomy were excluded. RESULTS: Four hundred and thirteen patients were treated for PDAC: 347 (84%) underwent PD and 66 (16%) DP. Tumors located in the pancreatic body and tail were significantly larger than their counterparts located in the head (30.6 mm vs. 41.2 mm; p < 0.001). However, distal tumors had significantly less nodal involvement (71% vs. 57%; p = 0.03). Portal-vein resection (PVR) was performed more often in PD, multivisceral resection (MVR) was more frequent in DP (37% vs. 14% and 4% vs. 29%; p < 0.001). Rates for negative resection margins and tumor grading were similar. Postoperative complication rates including morbidity, rates of re-operation and mortality were comparable. Long-term outcome revealed no significant difference between PD and DP with 5-year survival rates of 17.8 and 22% respectively (p = 0.284). Multivariate analysis confirmed positive resection margin, positive nodal status, extended resection (PVR, MVR) and lack of adjuvant/additive chemotherapy as independent risk factors for poor survival after pancreatic resection. CONCLUSION: Patients with resectable pancreatic ductal adenocarcinoma located in the body and tail of the pancreas display a similar postoperative oncological outcome despite larger tumors when compared to patients with resectable tumors located in the pancreatic head.