Neoadjuvant Therapy in Pancreatic Cancer: Review Article

Context Pancreatic cancer is still associated with a high mortality and morbidity for affected patients. To this date the role of neoadjuvant therapy in the standard treatment of pancreatic cancer remains elusive. The aim of our study was to review the latest results and current approaches in neoadjuvant therapy of pancreatic cancer. Methods We performed a literature review for neoadjuvant therapy in pancreatic cancer. We divided the results into resectable disease and local advanced pancreatic cancer. Results Neoadjuvant therapy in pancreatic cancer is safe. But currently no standard guidelines exist in neoadjuvant approaches on pancreatic cancer. For local advanced pancreatic cancer the available data tends to show a positive effect on survival rates for neoadjuvant approaches. Conclusion For resectable disease we found no benefit of neoadjuvant therapy. The negative or positive effects of neoadjuvant treatment in pancreatic cancer remain unclear for the lack of sufficient and prospective data.Image: University of Luebeck logo. Luebeck, Germany

Tumor engraftment in patient-derived xenografts of pancreatic ductal adenocarcinoma is associated with adverse clinicopathological features and poor survival

Patient-derived xenograft (PDX) tumors are powerful tools to study cancer biology. However, the ability of PDX tumors to model the biological and histological diversity of pancreatic ductal adenocarcinoma (PDAC) is not well known. In this study, we subcutaneously implanted 133 primary and metastatic PDAC tumors into immunodeficient mice. Fifty-seven tumors were successfully engrafted and even after extensive passaging, the histology of poorly-, moderately-, and well-differentiated tumors was maintained in the PDX models. Moreover, the fibroblast and collagen contents in the stroma of patient tumors were recapitulated in the corresponding PDX models. Analysis of the clinicopathological features of patients revealed xenograft tumor engraftment was associated with lymphovascular invasion (P = 0.001) and worse recurrence-free (median, 7 vs. 16 months, log-rank P = 0.047) and overall survival (median, 13 vs. 21 months, log-rank P = 0.038). Among successful engraftments, median time of growth required for reimplantation into new mice was 151 days. Reflective of the inherent biological diversity between PDX tumors with rapid (<151 days) and slow growth, differences in their growth were maintained during extensive passaging. Rapid growth was additionally associated with lymph node metastasis (P = 0.022). The association of lymphovascular invasion and lymph node metastasis with PDX formation and rapid growth may reflect an underlying biological mechanism that allows these tumors to adapt and grow in a new environment. While the ability of PDX tumors to mimic the cellular and non-cellular features of the parental tumor stroma provides a valuable model to study the interaction of PDAC cells with the tumor microenvironment, the association of successful engraftment with adverse clinicopathological features suggests PDX models over represent more aggressive forms of this disease

The Extracellular Matrix and Pancreatic Cancer: A Complex Relationship

Pancreatic ductal adenocarcinoma (PDAC) has an extraordinarily dense fibrotic stroma that impedes tumor perfusion and delivery of anticancer drugs. Since the extracellular matrix (ECM) comprises the bulk of the stroma, it is primarily responsible for the increased interstitial tissue pressure and stiff mechanical properties of the stroma. Besides its mechanical influence, the ECM provides important biochemical and physical cues that promote survival, proliferation, and metastasis. By serving as a nutritional source, the ECM also enables PDAC cells to survive under the nutrient-poor conditions. While therapeutic strategies using stroma-depleting drugs have yielded disappointing results, an increasing body of research indicates the ECM may offer a variety of potential therapeutic targets. As preclinical studies of ECM-targeted drugs have shown promising effects, a number of clinical trials are currently investigating agents with the potential to advance the future treatment of PDAC. Thus, the present review seeks to give an overview of the complex relationship between the ECM and PDAC

Regulation Mechanisms of the Hedgehog Pathway in Pancreatic Cancer: A Review

Pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of death from cancer. Its 5-year survival rate is less than 5%. This poor prognosis is mostly due to the cancer’s early invasion and metastasis formation, leading to an initial diagnosis at an advanced incurable stage in the majority of patients. The only potentially curative treatment is radical surgical resection. The effect of current chemotherapeutics or radiotherapy is limited. Novel therapeutic strategies are therefore much needed. One of the hallmarks of PDAC is its abundant desmoplastic (stromal) reaction. The Hedgehog (Hh) signaling pathway is critical for embryologic development of the pancreas. Aberrant Hh signaling promotes pancreatic carcinogenesis, the maintenance of the tumor microenvironment and stromal growth. The canonical Hh-pathway in the tumor stroma has been targeted widely but has not yet lead to hopeful clinical results. Targeting both the tumor and its surrounding stroma through Hh pathway inhibition by also targeting non-canonical pathways as apparent in the tumor cell may therefore be a novel treatment strategy for PDAC

A simple nomogram for early postoperative risk prediction of clinically relevant pancreatic fistula after pancreatoduodenectomy

Purpose!#!Postoperative pancreatic fistulae (POPF) present a serious and life-threatening complication after pancreatic head resections (PD). Therefore, reliable risk stratification to identify those at risk is urgently needed. The aim of this study was to identify postoperative laboratory parameters for the prediction of POPF in the early postoperative period.!##!Methods!#!One hundred eighty-two patients who underwent PD from 2012 until 2017 were retrospectively analyzed. Multivariate logistic regression was performed using the GLM (general linear model) method for model building. Two nomograms were created based on the GLM models of postoperative day one and postoperative day one to five. A cohort of 48 patients operated between 2018 and 2019 served as internal validation.!##!Results!#!Clinically relevant pancreatic fistulae (CR-POPF) were present in 16% (n = 29) of patients. Patients with CR-POPF experienced significantly more insufficiencies of gastroenterostomies, delayed gastric emptying, and more extraluminal bleeding than patients without CR-POPF. Multivariate analysis revealed multiple postoperative predictive models, the best one including ASA, main pancreatic duct diameter, operation time, and serum lipase as well as leucocytes on day one. This model was able to predict CR-POPF with an accuracy of 90% and an AUC of 0.903. Two nomograms were created for easier use.!##!Conclusion!#!Clinically relevant fistula can be predicted using simple laboratory and clinical parameters. Not serum amylase, but serum lipase is an independent predictor of CR-POPF. Our simple nomograms may help in the identification of patients for early postoperative interventions

Alignment of stroma fibers, microvessel density and immune cell populations determine overall survival in pancreatic cancer-An analysis of stromal morphology.

IntroductionThe aim of this study was to define histo-morphological stroma characteristics by analyzing stromal components, and to evaluate their impact on local and systemic tumor spread and overall survival in pancreatic ductal adenocarcinoma (PDAC).Methods and materialsPatients who underwent oncologic resections with curative intent for PDAC were identified from a prospectively maintained database. Histological specimens were re-evaluated for morphological stroma features as stromal fibers, fibroblast morphology, stroma matrix density, microvessel density and distribution of immune cell populations.ResultsA total of 108 patients were identified undergoing curative resection for PDAC in the period from 2011-2016. 33 (30.6%) patients showed parallel alignment of stroma fibers while 75 (69.4%) had randomly oriented stroma fibers. As compared to parallel alignment, random orientation of stroma fibers was associated with larger tumor size (median 3.62 cm vs. median 2.87cm, p = 0.037), nodal positive disease (76.0% vs. 54.5%, p = 0.040), higher margin positive resection rates (41.9% vs. 15.2%, p = 0.008) and a trend for higher rates of T3/4 tumors (33.3% vs. 15.2%, p = 0.064). In univariate analysis, patients with parallel alignment of stroma fibers had improved overall survival rates as compared to patients with random orientation of stroma fibers (42 months vs. 22 months, p = 0.046). The combination of random orientation of stroma fibers and low microvessel density was associated with impaired overall survival rates (16 months vs. 36 months, p = 0.019). A high CD4/CD3 ratio (16 months vs. 33 months, p = 0.040) and high stromal density of CD163 positive cells were associated with reduced overall survival (27 months vs. 34 months, p = 0.039). In multivariable analysis, the combination of random orientation of stroma fibers and low microvessel density (HR 1.592, 95%CI 1.098-2.733, p = 0.029), high CD4/CD3 ratio (HR 2.044, 95%CI 1.203-3.508, p = 0.028) and high density of CD163 positive cells (HR 1.596, 95%CI 1.367-1.968, p = 0.036) remained independent prognostic factors.ConclusionAlignment of stroma fibers and microvessel density are simple histomorphological features serving as surrogate markers of local tumor progression dissemination and surgical resectability and determine prognosis in PDAC patients. High CD4/CD3 ratio and CD163 positive cell counts determine poor prognosis

Outcome of pancreatic anastomoses during pancreatoduodenectomy in two national audits

Background: Evidence on the optimal pancreatic anastomosis during pancreatoduodenectomy is inconclusive. Large multicenter and nationwide registries may provide additional insights. The study compared the practice and outcome of different pancreatic anastomoses during pancreatoduodenectomy, focusing on the rate of postoperative pancreatic fistula, in two large audits of pancreatic surgery.Methods: Posthoc analysis of patients after pancreatoduodenectomy in the Dutch Pancreatic Cancer Audit and the German DGAV StuDoQ vertical bar Pancreas registries (January 2014 to December 2017). Postoperative pancreatic fistula (International Study Group of Pancreatic Surgery B/C), postpancreatectomy hemorrhage (International Study Group of Pancreatic Surgery B/C) and Clavien-Dindo >= 3 complications rates were compared for the three most common anastomoses: duct-to-mucosa pancreatojejunostomy, non-duct-to-mucosa pancreatojejunostomy, and non-duct-to-mucosa pancreatogastrostomy. Multivariable adjustment for potential confounders was performed.Results: Overall, 6,149 patients were included. The most common anastomosis was duct-to-mucosa pancreatojejunostomy (duct-to-mucosa pancreatojejunostomy 59.8%, non-duct-to-mucosa pancreatojejunostomy 21.1%, non-duct-to-mucosa pancreatogastrostomy 12.4%). The overall postoperative pancreatic fistula rate was 14%: duct-to-mucosa pancreatojejunostomy 12.9%, non-duct-to-mucosa pancreatojejunostomy 14.4% (P = .162), non-duct-to-mucosa pancreatogastrostomy 18.3% (P = 3 complications was the lowest after duct-to-mucosa pancreatojejunostomy: duct-to-mucosa pancreatojejunostomy 28%, non-duct-to-mucosa pancreatojejunostomy 32.7% (P = .002), non-duct-to-mucosa pancreatogastrostomy 43.1% (P = 3 (odds ratio 1.6, 95% confidence interval 1.2-2.1, P = .001) remained significantly higher only for non-duct-to-mucosa pancreatogastrostomy.Conclusion: Data from two national audits showed no difference in the risk-adjusted postoperative pancreatic fistula rate among the three most used pancreatic anastomoses during pancreatoduodenectomy. Pancreatogastrostomy was inferior to pancreatojejunostomy regarding bleeding and overall major complications. (C) 2021 Elsevier Inc. All rights reserved

Preoperative Biliary Stenting and Major Morbidity After Pancreatoduodenectomy

International audienc