Lymph node examination and survival in resected pancreatic ductal adenocarcinoma: retrospective study.

BACKGROUND: The minimum number of examined lymph nodes (ELN) required for adequate staging and best prediction of survival has not been established in pancreatic ductal adenocarcinoma (PDAC). The aim of the study was to investigate the influence of ELN on staging and survival in PDAC. METHODS: Patients undergoing partial or total pancreatectomy for PDAC at two European university hospitals between 2007 and 2018 were retrospectively reviewed. Multivariate Cox regression model and survival analyses were performed to verify adequate staging. RESULTS: Overall 341 (73 per cent) patients showed lymph node metastasis (N1/N2), whereas 125 (27 per cent) patients had no lymph node involvement (N0). With increasing number of ELN, the proportion of positive lymph nodes increased. The minimum number of ELN needed to detect lymph node involvement was 21. In multivariate analysis, examination of <21 lymph nodes was a significant negative predictor for survival. Examination of ≥21 ELN reversed this effect and ruled out possible misclassification. CONCLUSION: The number of ELN affects survival in PDAC. Possible misclassification was identified when <21 lymph nodes were examined. Therefore, at least 21 lymph nodes must be examined to avoid false lymph node classification in all types of resection.

Patterns and Relevance of Langerhans Islet Invasion in Pancreatic Cancer.

Background: Pancreatic cancer-associated diabetes mellitus (PC-DM) is present in most patients with pancreatic cancer, but its pathogenesis remains poorly understood. Therefore, we aimed to characterize tumor infiltration in Langerhans islets in pancreatic cancer and determine its clinical relevance. METHODS: Langerhans islet invasion was systematically analyzed in 68 patientswith pancreatic ductal adenocarcinoma (PDAC) using histopathological examination and 3D in vitro migration assays were performed to assess chemoattraction of pancreatic cancer cells to isletcells. RESULTS: Langerhans islet invasion was present in all patients. We found four different patterns of islet invasion: (Type I) peri-insular invasion with tumor cells directly touching the boundary, but not penetrating the islet; (Type II) endo-insular invasion with tumor cells inside the round islet; (Type III) distorted islet structure with complete loss of the round islet morphology; and (Type IV)adjacent cancer and islet cells with solitary islet cells encountered adjacent to cancer cells. Pancreatic cancer cells did not exhibit any chemoattraction to islet cells in 3D assays in vitro. Further, there was no clinical correlation of islet invasion using the novel Islet Invasion Severity Score (IISS), which includes all invasion patterns with the occurrence of diabetes mellitus. However, Type IV islet invasion was related to worsened overall survival in our cohort. CONCLUSIONS: We systematically analyzed, for the first time, islet invasion in human pancreatic cancer. Four different main patterns of islet invasion were identified. Diabetes mellitus was not related to islet invasion. However, moreresearch on this prevailing feature of pancreatic cancer is needed to better understand underlying principles.

A look at the progress of treating pancreatic cancer over the past 20 years.

INTRODUCTION: Pancreatic cancer is known to be the deadliest of all common cancers. Despite all efforts in pancreatic cancer treatment, the five-year survival rates at diagnosis over the past 20 years have only increased from 5% to 8%. Assuming that pancreatic cancer is going to become the second most frequent cause of cancer related death in the next 20 years, we are all encouraged to treat patients in clinical trials to gain improvements in this devastating disease. Areas covered: This review will provide a summary of pancreatic cancer treatment over the last 20 years, starting with the pivotal study in 1997 which showed the superiority of gemcitabine over 5-FU in advanced pancreatic cancer and is marked as the beginning of a new era in pancreatic cancer treatment. This review will also focus on improvements in different areas of treatment, including pancreatic surgery, adjuvant treatment, neoadjuvant therapy and palliative therapy. Expert commentary: The treatment of pancreatic cancer has changed substantially in the last 20 years compared to almost no improvements in the decades before. This provides hope that more effective treatment options will become available in the near future. Particularly, new concepts such as neoadjuvant therapy in resectable and borderline-resectable tumors may potentially shift treatment strategies.

Intraoperative wound irrigation to prevent surgical site infection after laparotomy (IOWISI): study protocol for a randomized controlled trial.

BACKGROUND: Postoperative surgical site infection (SSI) is one of the most common hospital infections and contributes substantially to postoperative morbidity and mortality. In addition, SSIs dramatically increase the treatment cost and length of hospital stay. Following visceral surgery by laparotomy, SSI rates are especially high (14-25%). Therefore, measures to prevent SSI in this field are urgently needed. Prophylactic intraoperative wound irrigation (IOWI) of the subcutaneous soft tissue before skin closure hypothetically represents an easy and economical option to reduce SSI rates and is already frequently used in clinical practice. However, there are currently no definite recommendations on the use of IOWI since high-level evidence supporting its use is lacking. Consequently, clinical practice varies widely. Antiseptic polyhexanide (PHX)-based solutions are approved for soft-tissue wound irrigation in surgery but have not been specifically evaluated in randomized clinical trials for the prevention of SSI following laparotomy for visceral surgery. METHODS/DESIGN: The IOWISI trial is a multicentre, randomized, observer- and patient-blinded clinical trial with three parallel treatment groups, comparing IOWI with a 0.04% PHX solution to no irrigation (test 1) or saline (test 2) before skin closure after laparotomy for visceral surgery (contamination level II-IV). The primary endpoint of the trial is the SSI rate within 30 days postoperatively. Statistical analysis of the primary endpoint measure will be based on the intention-to-treat population. The global level of significance is set at 2.5% for test 1 and 5% for test 2 and the sample size (n = 540) is determined to assure a power of 94% (test 1) and 85% (test 2). DISCUSSION: The IOWISI trial will provide high-level evidence as a basis for clinical recommendations regarding the use of IOWI with PHX or saline and will potentially impact on future clinical guidelines and practice. The pragmatic trial design guarantees high external validity. TRIAL REGISTRATION: Registered at the German Clinical Trials Register, DRKS00012251 . Registered on 3 July 2017.

The influence of neural invasion on survival and tumor recurrence in pancreatic ductal adenocarcinoma - A systematic review and meta-analysis.

OBJECTIVES: To assess the impact of neural invasion/NI on overall survival/OS and tumor recurrence in pancreatic ductal adenocarcinoma/PDAC. SUMMARY BACKGROUND DATA: NI is a histopathological hallmark of PDAC. Although some studies suggested an important role for NI on OS, disease-free/DFS and progression-free survival/PFS in PDAC, there is still no consensus on the actual role of NI on survival and local recurrence in PDAC. METHODS: Pubmed, Cochrane library, Ovid and Google Scholar were screened for the terms "pancreatic ductal adenocarcinoma", "pancreatic cancer", "survival", "tumor recurrence" and "perineural invasion". The Preferred-Reporting-Items-for-Systematic-review-and-Meta-Analysis/PRISMA-guidelines were used for systematic review and meta-analysis. Articles meeting predefined criteria were critically analysed on relevance, and meta-analyses were performed by pooling univariate and multivariate hazard ratios/HR. RESULTS: A total number of 25 studies on the influence of NI on tumor recurrence, and 121 studies analysing the influence of NI on survival were identified by systematic review. The HR of the univariate (HR 1.88; 95%-CI 1.71-2.07; p < 0.00001) and multivariate meta-analysis (HR 1.68; 95%-CI 1.47-1.92; p < 0.00001) showed a major impact of NI on OS. Likewise, NI was associated with decreased DFS (HR 2.53; 95%-CI: 1.67-3.83; p = 0.0001) and PFS (HR 2.41; 95%-CI: 1.73-3.37: p < 0.00001) multivariate meta-analysis. CONCLUSIONS: Although the power of this study is limited by missing pathological procedures to assess the true incidence of NI, NI appears to be an independent prognostic factor for OS, DFS and PFS in PDAC. Therefore, NI should be increasingly considered in patient stratification and in the development of novel therapeutic algorithms.

Pancreatic exocrine insufficiency after pancreatic surgery.

Pancreatic exocrine insufficiency is an often-underestimated complication following pancreatic surgery. After recent advances in managing acute postoperative complications the focus of current research is now shifting onto the long-term complications following pancreatectomy. Weight loss and steatorrhea as typical symptoms have high influence on the quality of life in the postoperative period. Malnutrition-related symptoms occur late and are often misinterpreted. Enzyme replacement therapy is more or less the only possible treatment option, even though not many controlled trials have been performed in this field. In this review we summarized the pathophysiology, diagnosis, risk factors and treatment options of exocrine insufficiency and focus mainly on patients with pancreaticoduodenectomy (classical Whipple), pylorus-preserving pancreaticoduodenectomy (ppWhipple) or distal pancreatectomy. Incidence of pancreatic exocrine insufficiency after surgery depends mainly on the initial diagnosis, the preoperative exocrine function and is associated with the extent of parenchyma resection. Diagnosing exocrine failure after surgery can be difficult and specific function tests are commonly not routinely performed. Starting and monitoring of enzyme replacement treatment is more based on clinical symptoms, than on objective markers. To improve the performance status of postsurgical patients it is important to consider pancreatic exocrine function as one aspect of quality of life. Further clinical trials should be initiated to gain more specific knowledge about the influence of the different pancreatic resections on pancreatic exocrine function to initialize proper treatment even before major clinical symptoms occur.