Polymorphisms in transcription factor binding sites and enhancer regions and pancreatic ductal adenocarcinoma risk.

Genome-wide association studies (GWAS) are a powerful tool for detecting variants associated with complex traits and can help risk stratification and prevention strategies against pancreatic ductal adenocarcinoma (PDAC). However, the strict significance threshold commonly used makes it likely that many true risk loci are missed. Functional annotation of GWAS polymorphisms is a proven strategy to identify additional risk loci. We aimed to investigate single-nucleotide polymorphisms (SNP) in regulatory regions [transcription factor binding sites (TFBSs) and enhancers] that could change the expression profile of multiple genes they act upon and thereby modify PDAC risk. We analyzed a total of 12,636 PDAC cases and 43,443 controls from PanScan/PanC4 and the East Asian GWAS (discovery populations), and the PANDoRA consortium (replication population). We identified four associations that reached study-wide statistical significance in the overall meta-analysis: rs2472632(A) (enhancer variant, OR 1.10, 95%CI 1.06,1.13, p = 5.5 × 10-8), rs17358295(G) (enhancer variant, OR 1.16, 95%CI 1.10,1.22, p = 6.1 × 10-7), rs2232079(T) (TFBS variant, OR 0.88, 95%CI 0.83,0.93, p = 6.4 × 10-6) and rs10025845(A) (TFBS variant, OR 1.88, 95%CI 1.50,1.12, p = 1.32 × 10-5). The SNP with the most significant association, rs2472632, is located in an enhancer predicted to target the coiled-coil domain containing 34 oncogene. Our results provide new insights into genetic risk factors for PDAC by a focused analysis of polymorphisms in regulatory regions and demonstrating the usefulness of functional prioritization to identify loci associated with PDAC risk.

Perioperative management of pancreatic exocrine insufficiency-evidence-based proposal for a paradigm shift in pancreatic surgery.

BACKGROUND: Despite exocrine pancreatic insufficiency (EPI) being a significant consequence of pancreatic surgery, there is still no consensus on its perioperative management. This study aimed to evaluate unselective pancreatic enzyme replacement therapy (PERT). METHODS: A prospective, observational study of patients undergoing partial pancreatectomy was conducted. EPI status was assessed pre- and postoperatively, based on three fecal-elastase measurements each. Characteristic symptoms were evaluated by questionnaire. In 85 post-surgical patients, the subjective burden of PERT was measured. RESULTS: 101 patients were followed prospectively. Preoperative EPI screening was available for 83 patients, of which 48% were diagnosed with preexisting EPI. Of those patients with regular exocrine function, 54% developed EPI de novo; this rate being higher following pancreatic head resections (72%) compared to left-sided pancreatectomies (LP) (20%) (p = 0.016). Overall postoperative EPI prevalence was significantly greater following pancreatic head resections (86%) than LP (33%) (p < 0.001). Only young and female patients described a significant burden related to PERT. CONCLUSION: For all patients undergoing pancreatic head resection PERT should be considered beginning prior to surgery, due to the subgroup's high EPI rate and the comparatively low burden of PERT. Patients with LP are at lower risk and should be pre- and postoperatively screened and supplemented accordingly.

Effects of Exercise Training on Patient-Specific Outcomes in Pancreatic Cancer Patients: A Scoping Review.

BACKGROUND: International guidelines have already highlighted the beneficial effects of exercise in common cancer entities. However, specific recommendations for pancreatic cancer are still missing. This scoping review aimed to evaluate the impact of exercise training on patient-specific outcomes in pancreatic cancer patients. METHODS: A literature search was undertaken using PubMed, Web of Science, and Cochrane Library. We included randomized controlled trials (RCTs) published before August 2023 with structured exercise interventions during or after pancreatic cancer treatment. RESULTS: Seven articles that prescribed home-based or supervised exercise with aerobic or resistance training or both were reviewed. The results indicate that exercise is feasible and safe in pancreatic cancer patients. Furthermore, exercise was associated with improved quality of life, cancer-related fatigue, and muscle strength. Concerning other outcomes, heterogeneous results were reported. We identified a lack of evidence, particularly for patients with advanced pancreatic cancer. CONCLUSION: Exercise interventions in pancreatic cancer patients are feasible and can lead to improved quality of life, cancer-related fatigue, and muscle strength. However, further studies with larger sample sizes are needed to clarify the potential of exercise in pancreatic cancer, in particular for advanced stages.

A scan of all coding region variants of the human genome, identifies 13q12.2-rs9579139 and 15q24.1-rs2277598 as novel risk loci for pancreatic ductal adenocarcinoma.

Coding sequence variants comprise a small fraction of the germline genetic variability of the human genome. However, they often cause deleterious change in protein function and are therefore associated with pathogenic phenotypes. To identify novel pancreatic ductal adenocarcinoma (PDAC) risk loci, we carried out a complete scan of all common missense and synonymous SNPs and analysed them in a case-control study comprising four different populations, for a total of 14 538 PDAC cases and 190 657 controls. We observed a statistically significant association between 13q12.2-rs9581957-T and PDAC risk (P = 2.46 × 10-9), that is in linkage disequilibrium (LD) with a deleterious missense variant (rs9579139) of the URAD gene. Recent findings suggest that this gene is active in peroxisomes. Considering that peroxisomes have a key role as molecular scavengers, especially in eliminating reactive oxygen species, a malfunctioning URAD protein might expose the cell to a higher load of potentially DNA damaging molecules and therefore increase PDAC risk. The association was observed in individuals of European and Asian ethnicity. We also observed the association of the missense variant 15q24.1-rs2277598-T, that belongs to BBS4 gene, with increased PDAC risk (P = 1.53 × 10-6). rs2277598 is associated with body mass index and is in LD with diabetes susceptibility loci. In conclusion, we identified two missense variants associated with the risk of developing PDAC independently from the ethnicity highlighting the importance of conducting reanalysis of genome-wide association studies (GWASs) in light of functional data.

Exploring the Neandertal legacy of pancreatic ductal adenocarcinoma risk in Eurasians.

BACKGROUND: The genomes of present-day non-Africans are composed of 1-3% of Neandertal-derived DNA as a consequence of admixture events between Neandertals and anatomically modern humans about 50-60 thousand years ago. Neandertal-introgressed single nucleotide polymorphisms (aSNPs) have been associated with modern human disease-related traits, which are risk factors for pancreatic ductal adenocarcinoma (PDAC), such as obesity, type 2 diabetes, and inflammation. In this study, we aimed at investigating the role of aSNPs in PDAC in three Eurasian populations. RESULTS: The high-coverage Vindija Neandertal genome was used to select aSNPs in non-African populations from 1000 Genomes project phase 3 data. Then, the association between aSNPs and PDAC risk was tested independently in Europeans and East Asians, using existing GWAS data on more than 200 000 individuals. We did not find any significant associations between aSNPs and PDAC in samples of European descent, whereas, in East Asians, we observed that the Chr10p12.1-rs117585753-T allele (MAF = 10%) increased the risk to develop PDAC (OR = 1.35, 95%CI 1.19-1.54, P = 3.59 × 10-6), with a P-value close to a threshold that takes into account multiple testing. CONCLUSIONS: Our results show only a minimal contribution of Neandertal SNPs to PDAC risk.

Microbiota-derived 3-IAA influences chemotherapy efficacy in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is expected to be the second most deadly cancer by 2040, owing to the high incidence of metastatic disease and limited responses to treatment1,2. Less than half of all patients respond to the primary treatment for PDAC, chemotherapy3,4, and genetic alterations alone cannot explain this5. Diet is an environmental factor that can influence the response to therapies, but its role in PDAC is unclear. Here, using shotgun metagenomic sequencing and metabolomic screening, we show that the microbiota-derived tryptophan metabolite indole-3-acetic acid (3-IAA) is enriched in patients who respond to treatment. Faecal microbiota transplantation, short-term dietary manipulation of tryptophan and oral 3-IAA administration increase the efficacy of chemotherapy in humanized gnotobiotic mouse models of PDAC. Using a combination of loss- and gain-of-function experiments, we show that the efficacy of 3-IAA and chemotherapy is licensed by neutrophil-derived myeloperoxidase. Myeloperoxidase oxidizes 3-IAA, which in combination with chemotherapy induces a downregulation of the reactive oxygen species (ROS)-degrading enzymes glutathione peroxidase 3 and glutathione peroxidase 7. All of this results in the accumulation of ROS and the downregulation of autophagy in cancer cells, which compromises their metabolic fitness and, ultimately, their proliferation. In humans, we observed a significant correlation between the levels of 3-IAA and the efficacy of therapy in two independent PDAC cohorts. In summary, we identify a microbiota-derived metabolite that has clinical implications in the treatment of PDAC, and provide a motivation for considering nutritional interventions during the treatment of patients with cancer.

Peripheral and Portal Venous KRAS ctDNA Detection as Independent Prognostic Markers of Early Tumor Recurrence in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: KRAS circulating tumor DNA (ctDNA) has shown biomarker potential for pancreatic ductal adenocarcinoma (PDAC) but has not been applied in clinical routine yet. We aim to improve clinical applicability of ctDNA detection in PDAC and to study the impact of blood-draw site and time point on the detectability and prognostic role of KRAS mutations. METHODS: 221 blood samples from 108 PDAC patients (65 curative, 43 palliative) were analyzed. Baseline peripheral and tumor-draining portal venous (PV), postoperative, and follow-up blood were analyzed and correlated with prognosis. RESULTS: Significantly higher KRAS mutant detection rates and copy numbers were observed in palliative compared to curative patients baseline blood (58.1% vs 24.6%; P = 0.002; and P < 0.001). Significantly higher KRAS mutant copies were found in PV blood compared to baseline (P < 0.05) samples. KRAS detection in pre- and postoperative and PV blood were significantly associated with shorter recurrence-free survival (all P < 0.015) and identified as independent prognostic markers. KRAS ctDNA status was also an independent unfavorable prognostic factor for shorter overall survival in both palliative and curative cohorts (hazard ratio [HR] 4.9, P = 0.011; HR 6.9, P = 0.008). CONCLUSIONS: KRAS ctDNA detection is an independent adverse prognostic marker in curative and palliative PDAC patients-at all sites of blood draw and a strong follow-up marker. The most substantial prognostic impact was seen for PV blood, which could be an effective novel tool for identifying prognostic borderline patients-guiding future decision-making on neoadjuvant treatment despite anatomical resectability. In addition, higher PV mutant copy numbers contribute to an improved technical feasibility.

A Critical Role of the IL-22-IL-22 Binding Protein Axis in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) ranks among the five most common cancer entities worldwide and leads to hundred-thousands of deaths every year. Despite some groundbreaking therapeutical revelations during the last years, the overall prognosis remains poor. Although the immune system fights malignant transformations with a robust anti-tumor response, certain immune mediators have also been shown to promote cancer development. For example, interleukin (IL)-22 has been associated with HCC progression and worsened prognosis in multiple studies. However, the underlying mechanisms of the pathological role of IL-22-signaling as well as the role of its natural antagonist IL-22 binding protein (IL-22BP) in HCC remain elusive. Here, we corroborate the pathogenic role of IL-22 in HCC by taking advantage of two mouse models. Moreover, we observed a protective role of IL-22BP during liver carcinogenesis. While IL-22 was mainly produced by CD4+ T cells in HCC, IL-22BP was abundantly expressed by neutrophils during liver carcinogenesis. Hepatocytes could be identified as a major target of this pathological IL-22-signaling. Moreover, abrogation of IL-22 signaling in hepatocytes in IL22ra1flox/flox × AlbCre+ mice reduced STEAP4 expression-a known oncogene-in HCC in vivo. Likewise, STEAP4 expression correlated with IL22 levels in human HCC samples, but not in healthy liver specimens. In conclusion, these data encourage the development of therapeutical approaches that target the IL-22-IL-22BP axis in HCC.

Circulating Cancer Associated Macrophage-like Cells as a Potential New Prognostic Marker in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Circulating Cancer Associated Macrophage-like cells (CAMLs) have been described as novel liquid biopsy analytes and unfavorable prognostic markers in some tumor entities, with scarce data for Pancreatic Ductal Adenocarcinomas (PDAC). METHODS: Baseline and follow-up blood was drawn from resected curative (n = 36) and palliative (n = 19) PDAC patients. A microfluidic size-based cell enrichment approach (ParsortixTM) was used for CAML detection, followed by immunofluorescence staining using pan-keratin, CD14, and CD45 antibodies to differentiate between CAMLs, circulating tumor cells (CTCs), and leukocytes. RESULTS: CAMLs were detectable at baseline in 36.1% of resected patients and 47.4% of palliative PDAC patients. CAML detection was tumor stage independent. Follow-up data indicated that detection of CAMLs (in 45.5% of curative patients) was an independent prognostic factor for shorter recurrence-free survival (RFS) (HR: 4.3, p = 0.023). Furthermore, a combined analysis with CTCs showed the detectability of at least one of these cell populations in 68.2% of resected patients at follow-up. The combined detection of CAMLs and CTCs was also significantly associated with short RFS (HR: 8.7, p = 0.003). CONCLUSIONS: This pilot study shows that detection of CAMLs in PDAC patients can provide prognostic information, either alone or even more pronounced in combination with CTCs, which indicates the power of liquid biopsy marker analyses.

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.

Characterization of RARRES1 Expression on Circulating Tumor Cells as Unfavorable Prognostic Marker in Resected Pancreatic Ductal Adenocarcinoma Patients.

BACKGROUND: In pancreatic ductal adenocarcinoma (PDAC), the characterization of circulating tumor cells (CTCs) opens new insights into cancer metastasis as the leading cause of cancer-related death. Here, we focused on the expression of retinoic acid receptor responder 1 (RARRES1) on CTCs as a novel marker for treatment failure and early relapse. METHODS: The stable isotope labeling of amino acids in cell culture (SILAC)-approach was applied for identifying and quantifying new biomarker proteins in PDAC cell lines HPDE and its chemoresistant counterpart, L3.6pl-Res. Fifty-five baseline and 36 follow-up (FUP) peripheral blood samples were processed via a marker-independent microfluidic-based CTC detection approach using RARRES1 as an additional marker. RESULTS: SILAC-based proteomics identified RARRES1 as an abundantly expressed protein in more aggressive chemoresistant PDAC cells. At baseline, CTCs were detected in 25.5% of all PDAC patients, while FUP analysis (median: 11 months FUP) showed CTC detection in 45.5% of the resected patients. CTC positivity (≥3 CTC) at FUP was significantly associated with short recurrence-free survival (p = 0.002). Furthermore, detection of RARRES1 positive CTCs was indicative of an even earlier relapse after surgery (p = 0.001). CONCLUSIONS: CTC detection in resected PDAC patients during FUP is associated with a worse prognosis, and RARRES1 expression might identify an aggressive subtype of CTCs that deserves further investigation.

Tumor-Stroma Interaction in PDAC as a New Approach for Liquid Biopsy and its Potential Clinical Implications.

The extremely poor prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) has remained unchanged for decades. As a hallmark of PDAC histology, the distinct desmoplastic response in the tumor microenvironment is considered a key factor exerting pro- and antitumor effects. Increasing emphasis has been placed on cancer-associated fibroblasts (CAFs), whose heterogeneity and functional diversity is reflected in the numerous subtypes. The myofibroblastic CAFs (myCAFs), inflammatory CAFs (iCAFs) and antigen presenting CAFs (apCAFs) are functionally divergent CAF subtypes with tumor promoting as well as repressing effects. Precise knowledge of the underlying interactions is the basis for a variety of treatment approaches, which are subsumed under the term antistromal therapy. Clinical implementation is still pending due to the lack of benefit-as well as paradoxical preclinical findings. While the prominent significance of CAFs in the immediate environment of the tumor is becoming clear, less is known about the circulating (c)CAFs. cCAFs are of particular interest as they seem not only to be potential new liquid biopsy biomarkers but also to support the survival of circulating tumor cells (CTC) in the bloodstream. In PDAC, CTCs correlate with an unfavorable outcome and can also be employed to monitor treatment response, but the current clinical relevance is limited. In this review, we discuss CTCs, cCAFs, secretomes that include EVs or fragments of collagen turnover as liquid biopsy biomarkers, and clinical approaches to target tumor stroma in PDAC.

CD147 expression lacks prognostic relevance in esophageal cancer.

INTRODUCTION: The role of CD147 as an important indicator of tumor prognosis remains controversially discussed in literature. We focused on the prognostic significance of CD147 expression in esophageal cancer patients. While some studies report that CD147 is an unfavorable prognostic factor in esophageal squamous cell carcinoma, others showed no significant correlation. However, only one study draws attention to the significance of CD147 in esophageal adenocarcinoma, which is one of the most rapidly increasing neoplasms in the western world. METHODS: To finally clarify the impact of CD147 as a prognostic factor, especially for esophageal adenocarcinomas, we analyzed CD147 expression in a tissue microarray of 359 esophageal adenocarcinomas and 254 esophageal squamous cell cancer specimens. For the immuno-histochemical analysis, we used a primary antibody specific for CD147. Staining intensity and proportion of positive tumor cells were scored (negative, weak, moderate, strong staining). These findings were compared to normal esophageal tissue and correlated to the histopathological tumor phenotype and survival data. RESULTS: CD147 expression was detectable in weak intensities in benign esophageal tissue (85.78%) and expressed in predominately moderate to strong intensities in esophageal cancer (88.34%). Strong CD147 immunostaining was linked to increased infiltration depth (p = 0.015) and differentiation (p = 0.016) in esophageal squamous cell cancer but revealed no significant correlation with histopathology of adenocarcinoma. Moreover, CD147 intensity was unrelated to overall survival in this collective for both subtypes of esophageal cancer. CONCLUSION: Thus, our data show that CD147 has no prognostic value, neither in esophageal adenocarcinoma nor squamous cell carcinoma.

Effective sealing of biliary and pancreatic fistulas with a novel biodegradable polyurethane-based tissue sealant patch.

BACKGROUND: To date, no approved sealants for the prevention of postoperative pancreatic fistulas (POPFs) or bile leakage are available. The aim of the study is to assess the feasibility of a new synthetic and biodegradable polyurethane-based sealant patch (PBSP) for hepato-pancreato-biliary (HPB) surgery. METHODS: Benchmarking of the PBSP with commercially available products with a historical use in HPB surgery (Tachosil®, Hemopatch®, Surgicel® and Veriset®) was followed by performance testing in randomized controlled porcine animal studies. These studies focused on haemostasis as well as the prevention of POPFs and bile leakage. RESULTS: The newly designed PBSP demonstrated the strongest adherence to liver tissue compared to Tachosil®, Hemopatch® and Veriset®. The new patch was the only patch with complete intra- and postoperative hemostasis (72 h after application) compared to Tachosil and Veriset in a porcine liver abrasion study on 12 animals. In addition, the new patch demonstrably prevents the development of POPFs. The rate of postoperative pancreatitis and clinically relevant POPFs was significantly lower compared to the control groups in a porcine pancreatic fistula model based on 14 animals (14-day follow-up). Furthermore, the incidence of biloma after 7 days, considered as significant bile leakage, was significantly lower in the new PBSP compared to the Veriset® group. The PBSP was as effective as suturing in a porcine bile leakage model (7-day follow-up). CONCLUSION: The PBSP induces constant hemostasis in the context of liver resection and prevents pancreatic fistulas and bile leakage. The promising preclinical data implicate clinical trials for further evaluation of this newly developed patch.

Evaluation of the Hamburg-Glasgow Classification in Pancreatic Cancer: Preoperative Staging by Combining Disseminated Tumor Load and Systemic Inflammation.

This study aims to compare the Hamburg Glasgow Classification (HGC) to Union for International Cancer Control (UICC) classification in patients with pancreatic ductal adenocarcinoma (PDAC). As adequate tumor classification is only possible after tumor resection and histological evaluation, only 20% of patients with PDAC receive accurate tumor staging. Thus, an accurate preoperative staging system is still missing but urgently needed. Systemic inflammation and tumor dissemination are important factors regarding the oncological outcome. HGC integrates both into a preoperative staging system, by combining C-reactive protein (CRP), albumin, and disseminated tumor cells (DTC) in the bone marrow. In this prospective study, 109 patients underwent surgical exploration for suspected PDAC. All patients underwent a preoperative bone marrow aspiration for DTC detection. HGC showed significant preoperative risk stratification for overall survival (OS) (p-value < 0.001) and progression-free survival (PFS) (p-value < 0.001). These results were comparable to the UICC survival stratification for OS and PFS (p-value = 0.001 and 0.006). Additionally, in non-metastatic PDAC, HGC III-IV was associated with shorter OS and PFS (p-value < 0.001, respectively) when compared to HGC I-II. Therefore, the HGC is a promising preoperative prognostic staging classification for accurate and simple outcome stratification in patients with PDAC.

Identification of Recessively Inherited Genetic Variants Potentially Linked to Pancreatic Cancer Risk.

Although 21 pancreatic cancer susceptibility loci have been identified in individuals of European ancestry through genome-wide association studies (GWASs), much of the heritability of pancreatic cancer risk remains unidentified. A recessive genetic model could be a powerful tool for identifying additional risk variants. To discover recessively inherited pancreatic cancer risk loci, we performed a re-analysis of the largest pancreatic cancer GWAS, the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case-Control Consortium (PanC4), including 8,769 cases and 7,055 controls of European ancestry. Six single nucleotide polymorphisms (SNPs) showed associations with pancreatic cancer risk according to a recessive model of inheritance. We replicated these variants in 3,212 cases and 3,470 controls collected from the PANcreatic Disease ReseArch (PANDoRA) consortium. The results of the meta-analyses confirmed that rs4626538 (7q32.2), rs7008921 (8p23.2) and rs147904962 (17q21.31) showed specific recessive effects (p<10-5) compared with the additive effects (p>10-3), although none of the six SNPs reached the conventional threshold for genome-wide significance (p < 5×10-8). Additional bioinformatic analysis explored the functional annotations of the SNPs and indicated a possible relationship between rs36018702 and expression of the BCL2L11 and BUB1 genes, which are known to be involved in pancreatic biology. Our findings, while not conclusive, indicate the importance of considering non-additive genetic models when performing GWAS analysis. The SNPs associated with pancreatic cancer in this study could be used for further meta-analysis for recessive association of SNPs and pancreatic cancer risk and might be a useful addiction to improve the performance of polygenic risk scores.

Genetic Polymorphisms Involved in Mitochondrial Metabolism and Pancreatic Cancer Risk.

BACKGROUND: The mitochondrial metabolism has been associated with pancreatic ductal adenocarcinoma (PDAC) risk. Recent evidence also suggests the involvement of the genetic variability of the mitochondrial function in several traits involved in PDAC etiology. However, a systematic investigation of the genetic variability of mitochondrial genome (mtSNP) and of all the nuclear genes involved in its functioning (n-mtSNPs) has never been reported. METHODS: We conducted a two-phase association study of mtSNPs and n-mtSNPs to assess their effect on PDAC risk. We analyzed 35,297 n-mtSNPs and 101 mtSNPs in up to 55,870 individuals (12,884 PDAC cases and 42,986 controls). In addition, we also conducted a gene-based analysis on 1,588 genes involved in mitochondrial metabolism using Multi-marker Analysis of GenoMic Annotation (MAGMA) software. RESULTS: In the discovery phase, we identified 49 n-mtSNPs and no mtSNPs associated with PDAC risk (P < 0.05). In the second phase, none of the findings were replicated. In the gene-level analysis, we observed that three genes (TERT, SUGCT, and SURF1) involved in the mitochondrial metabolism showed an association below the Bonferroni-corrected threshold of statistical significance (P = 0.05/1588 = 3.1 × 10-5). CONCLUSIONS: Even though the mitochondrial metabolism might be involved in PDAC etiology, our results, obtained in a study with one of the largest sample sizes to date, show that neither n-mtSNPs nor mtSNPs are associated with PDAC risk. IMPACT: This large case-control study does not support a role of the genetic variability of the mitochondrial function in PDAC risk.

Association of Genetic Variants Affecting microRNAs and Pancreatic Cancer Risk.

Genetic factors play an important role in the susceptibility to pancreatic cancer (PC). However, established loci explain a small proportion of genetic heritability for PC; therefore, more progress is needed to find the missing ones. We aimed at identifying single nucleotide polymorphisms (SNPs) affecting PC risk through effects on micro-RNA (miRNA) function. We searched in silico the genome for SNPs in miRNA seed sequences or 3 prime untranslated regions (3'UTRs) of miRNA target genes. Genome-wide association data of PC cases and controls from the Pancreatic Cancer Cohort (PanScan) Consortium and the Pancreatic Cancer Case-Control (PanC4) Consortium were re-analyzed for discovery, and genotyping data from two additional consortia (PanGenEU and PANDoRA) were used for replication, for a total of 14,062 cases and 11,261 controls. None of the SNPs reached genome-wide significance in the meta-analysis, but for three of them the associations were in the same direction in all the study populations and showed lower value of p in the meta-analyses than in the discovery phase. Specifically, rs7985480 was consistently associated with PC risk (OR = 1.12, 95% CI 1.07-1.17, p = 3.03 × 10-6 in the meta-analysis). This SNP is in linkage disequilibrium (LD) with rs2274048, which modulates binding of various miRNAs to the 3'UTR of UCHL3, a gene involved in PC progression. In conclusion, our results expand the knowledge of the genetic PC risk through miRNA-related SNPs and show the usefulness of functional prioritization to identify genetic polymorphisms associated with PC risk.

Evidence Map of Pancreatic Surgery-A living systematic review with meta-analyses by the International Study Group of Pancreatic Surgery (ISGPS).

BACKGROUND: Pancreatic surgery is associated with considerable morbidity and, consequently, offers a large and complex field for research. To prioritize relevant future scientific projects, it is of utmost importance to identify existing evidence and uncover research gaps. Thus, the aim of this project was to create a systematic and living Evidence Map of Pancreatic Surgery. METHODS: PubMed, the Cochrane Central Register of Controlled Trials, and Web of Science were systematically searched for all randomized controlled trials and systematic reviews on pancreatic surgery. Outcomes from every existing randomized controlled trial were extracted, and trial quality was assessed. Systematic reviews were used to identify an absence of randomized controlled trials. Randomized controlled trials and systematic reviews on identical subjects were grouped according to research topics. A web-based evidence map modeled after a mind map was created to visualize existing evidence. Meta-analyses of specific outcomes of pancreatic surgery were performed for all research topics with more than 3 randomized controlled trials. For partial pancreatoduodenectomy and distal pancreatectomy, pooled benchmarks for outcomes were calculated with a 99% confidence interval. The evidence map undergoes regular updates. RESULTS: Out of 30,860 articles reviewed, 328 randomized controlled trials on 35,600 patients and 332 systematic reviews were included and grouped into 76 research topics. Most randomized controlled trials were from Europe (46%) and most systematic reviews were from Asia (51%). A living meta-analysis of 21 out of 76 research topics (28%) was performed and included in the web-based evidence map. Evidence gaps were identified in 11 out of 76 research topics (14%). The benchmark for mortality was 2% (99% confidence interval: 1%-2%) for partial pancreatoduodenectomy and <1% (99% confidence interval: 0%-1%) for distal pancreatectomy. The benchmark for overall complications was 53% (99%confidence interval: 46%-61%) for partial pancreatoduodenectomy and 59% (99% confidence interval: 44%-80%) for distal pancreatectomy. CONCLUSION: The International Study Group of Pancreatic Surgery Evidence Map of Pancreatic Surgery, which is freely accessible via www.evidencemap.surgery and as a mobile phone app, provides a regularly updated overview of the available literature displayed in an intuitive fashion. Clinical decision making and evidence-based patient information are supported by the primary data provided, as well as by living meta-analyses. Researchers can use the systematic literature search and processed data for their own projects, and funding bodies can base their research priorities on evidence gaps that the map uncovers.

Prospective Comparison of the Prognostic Relevance of Circulating Tumor Cells in Blood and Disseminated Tumor Cells in Bone Marrow of a Single Patient's Cohort With Esophageal Cancer.

OBJECTIVE: Aim of this prospective study was to evaluate the prognostic significance of disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) in 1 cohort of patients with esophageal cancer (EC). BACKGROUND: Hematogenous tumor cell dissemination is a key event in tumor progression, and clinical significance of DTCs and CTCs are controversially discussed in the literature. However, evaluation of both biomarker in 1 patient's cohort has not been described before. METHODS: In this prospective, single-center study, 76 patients with preoperatively nonmetastatic staged EC were included. The CellSearch system was used to enumerate CTCs. Bone marrow was aspirated from the iliac crest and cells were enriched by Ficoll density gradient centrifugation. DTCs were immunostained with the pan-keratin antibody A45-B/B3. RESULTS: Fifteen of 76 patients (19.7%) harbored CTCs, whereas in 13 of 76 patients (17.1%), DTCs could be detected. In only 3 patients (3.9%), CTCs and DTCs were detected simultaneously, whereas concordant results (DTC/CTC negative and DTC/CTC positive) were found in 54 patients (71.1%). Surprisingly, only patients with CTCs showed significant shorter overall and relapse-free survival (P = 0.038 and P = 0.004, respectively). Multivariate analyses revealed that only the CTC status was an independent predictor of overall and relapse-free survival (P = 0.007 and P < 0.001, respectively). CONCLUSIONS: This is the first study analyzing CTC and DTC status in 1 cohort of nonmetastatic patients with EC. In this early disease stage, only the CTC status was an independent, prognostic marker suitable and easy to use for clinical staging of patients with EC.