Pancreatic carcinoma

10 years of BiTE immunotherapy: an overview with a focus on pancreatic cancer

Various therapeutic strategies have been developed to treat Pancreatic Cancer (PaCa). Unfortunately, most efforts have proved unfruitful, as the poor prognosis observed in this disease has only attained little improvement in the past 40 years. Recently, deeper understanding of the immune system and its interaction with malignant tumors have allowed significant advances in immunotherapy. Consistent with this, some of the most promising approaches are those that involve T-cell redirection to the tumor site, such as bispecific T-cell engagers (BiTEs). These recombinant antibodies bridge cytotoxic T-cells to tumor cells, inducing target cell-dependent polyclonal T-cell activation/proliferation, which in turn results in elimination of bound tumor cells. Blinatumomab, an anti-CD19 BiTE, received FDA approval in 2014 for Precursor B-cell Acute Lymphoblastic Leukemia. In the past decade, it has demonstrated impressive clinical benefit in patients with B-cell leukemias; and other T-cell engagers have been FDA-approved for hematological malignancies and other diseases, yet limited effect has been observed with other BiTEs against solid cancers, including PaCa. Nevertheless, on May 2024, Tarlatamab, an anti-DLL3 BiTE was approved by the FDA for extensive small cell lung cancer, becoming the first BiTE for solid tumors. In this review, the generation of BiTEs, therapeutic features, manufacturing issues as well as the remaining challenges and novel strategies of BiTE therapy in the context of PaCa, including the lessons we can learn from the use of BiTEs on other types of cancer will be explored.

Chemotherapy and radiotherapy for advanced pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a lethal disease with few effective treatment options. Many anti-cancer therapies have been tested in the locally advanced and metastatic setting, with mixed results. This review synthesises all the randomised data available to help better inform patient and clinician decision-making. It updates the previous version of the review, published in 2018.

OBJECTIVES

To assess the effects of chemotherapy, radiotherapy, or both on overall survival, severe or life-threatening adverse events, and quality of life in people undergoing first-line treatment of advanced pancreatic cancer.

SEARCH METHODS

We searched for published and unpublished studies in CENTRAL, MEDLINE, Embase, and CANCERLIT, and handsearched various sources for additional studies. The latest search dates were in March and July 2023.

SELECTION CRITERIA

We included randomised controlled trials comparing chemotherapy, radiotherapy, or both with another intervention or best supportive care. Participants were required to have locally advanced, unresectable pancreatic cancer or metastatic pancreatic cancer not amenable to curative intent treatment. Histological confirmation was required. Trials were required to report overall survival.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 75 studies in the review and 51 in the meta-analysis (11,333 participants). We divided the studies into seven categories: any anti-cancer treatment versus best supportive care; various chemotherapy types versus gemcitabine; gemcitabine-based combinations versus gemcitabine alone; various chemotherapy combinations versus gemcitabine plus nab-paclitaxel; fluoropyrimidine-based studies; miscellaneous studies; and radiotherapy studies. In general, the included studies were at low risk for random sequence generation, detection bias, attrition bias, and reporting bias, at unclear risk for allocation concealment, and high risk for performance bias. Compared to best supportive care, chemotherapy likely results in little to no difference in overall survival (OS) (hazard ratio (HR) 1.08, 95% confidence interval (CI) 0.88 to 1.33; absolute risk of death at 12 months of 971 per 1000 versus 962 per 1000; 4 studies, 298 participants; moderate-certainty evidence). The adverse effects of chemotherapy and impacts on quality of life (QoL) were uncertain. Many of the chemotherapy regimens were outdated. Eight studies compared non-gemcitabine-based chemotherapy regimens to gemcitabine. These showed that 5-fluorouracil (5FU) likely reduces OS (HR 1.69, 95% CI 1.26 to 2.27; risk of death at 12 months of 914 per 1000 versus 767 per 1000; 1 study, 126 participants; moderate certainty), and grade 3/4 adverse events (QoL not reported). Fixed dose rate gemcitabine likely improves OS (HR 0.79, 95% CI 0.66 to 0.94; risk of death at 12 months of 683 per 1000 versus 767 per 1000; 2 studies, 644 participants; moderate certainty), and likely increase grade 3/4 adverse events (QoL not reported). FOLFIRINOX improves OS (HR 0.51, 95% CI 0.43 to 0.60; risk of death at 12 months of 524 per 1000 versus 767 per 1000; P < 0.001; 2 studies, 652 participants; high certainty), and delays deterioration in QoL, but increases grade 3/4 adverse events. Twenty-eight studies compared gemcitabine-based combinations to gemcitabine. Gemcitabine plus platinum may result in little to no difference in OS (HR 0.94, 95% CI 0.81 to 1.08; risk of death at 12 months of 745 per 1000 versus 767 per 1000; 6 studies, 1140 participants; low certainty), may increase grade 3/4 adverse events, and likely worsens QoL. Gemcitabine plus fluoropyrimidine improves OS (HR 0.88, 95% CI 0.81 to 0.95; risk of death at 12 months of 722 per 1000 versus 767 per 1000; 10 studies, 2718 participants; high certainty), likely increases grade 3/4 adverse events, and likely improves QoL. Gemcitabine plus topoisomerase inhibitors result in little to no difference in OS (HR 1.01, 95% CI 0.87 to 1.16; risk of death at 12 months of 770 per 1000 versus 767 per 1000; 3 studies, 839 participants; high certainty), likely increases grade 3/4 adverse events, and likely does not alter QoL. Gemcitabine plus taxane result in a large improvement in OS (HR 0.71, 95% CI 0.62 to 0.81; risk of death at 12 months of 644 per 1000 versus 767 per 1000; 2 studies, 986 participants; high certainty), and likely increases grade 3/4 adverse events and improves QoL. Nine studies compared chemotherapy combinations to gemcitabine plus nab-paclitaxel. Fluoropyrimidine-based combination regimens improve OS (HR 0.79, 95% CI 0.70 to 0.89; risk of death at 12 months of 542 per 1000 versus 628 per 1000; 6 studies, 1285 participants; high certainty). The treatment arms had distinct toxicity profiles, and there was little to no difference in QoL. Alternative schedules of gemcitabine plus nab-paclitaxel likely result in little to no difference in OS (HR 1.10, 95% CI 0.82 to 1.47; risk of death at 12 months of 663 per 1000 versus 628 per 1000; 2 studies, 367 participants; moderate certainty) or QoL, but may increase grade 3/4 adverse events. Four studies compared fluoropyrimidine-based combinations to fluoropyrimidines alone, with poor quality evidence. Fluoropyrimidine-based combinations are likely to result in little to no impact on OS (HR 0.84, 95% CI 0.61 to 1.15; risk of death at 12 months of 765 per 1000 versus 704 per 1000; P = 0.27; 4 studies, 491 participants; moderate certainty) versus fluoropyrimidines alone. The evidence suggests that there was little to no difference in grade 3/4 adverse events or QoL between the two groups. We included only one radiotherapy (iodine-125 brachytherapy) study with 165 participants. The evidence is very uncertain about the effect of radiotherapy on outcomes.

AUTHORS' CONCLUSIONS

Combination chemotherapy remains standard of care for metastatic pancreatic cancer. Both FOLFIRINOX and gemcitabine plus a taxane improve OS compared to gemcitabine alone. Furthermore, the evidence suggests that fluoropyrimidine-based combination chemotherapy regimens improve OS compared to gemcitabine plus nab-paclitaxel. The effects of radiotherapy were uncertain as only one low-quality trial was included. Selection of the most appropriate chemotherapy for individuals still remains unpersonalised, with clinicopathological stratification remaining elusive. Biomarker development is essential to assist in rationalising treatment selection for patients.

Endoscopic ultrasound-guided gastroenterostomy versus duodenal stenting for gastric outlet obstruction: A systematic review, meta-analysis, and meta-regression

BACKGROUND

Gastric outlet obstruction (GOO) refers to mechanical obstruction at the level of the gastric outlet and is associated with significantly impacted quality of life and mortality. Duodenal stenting (DS) offers a minimally invasive approach to managing GOO but is associated with a high risk of stent obstruction. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is a novel intervention that uses lumen-apposing metal stents to open the restricted lumen. The current evidence comparing EUS-GE to DS is limited and inconsistent.

METHODS

We conducted a systematic literature search on PubMed, Embase, Cochrane, Scopus, and clinicaltrials.gov to retrieve studies comparing EUS-GE to DS for GOO. Odds ratios (OR) and mean differences (MD) with their 95% confidence intervals (CI) were pooled using the DerSimonian-Laird inverse variance random-effects model. Statistical significance was set at P < .05.

RESULTS

Ten studies with a total of 1275 GOO patients (585: EUS-GE and 690: DS) were included. EUS-GE was associated with statistically significant higher clinical success [OR: 2.52; 95% CI: 1.64, 3.86; P < .001], lower re-intervention rate [OR: 0.12; 95% CI: 0.06, 0.22; P < .00001], longer procedural time [MD: 20.91; 95% CI: 15.48, 26.35; P < .00001], and lower risk of adverse events [OR: 0.49; 95% CI: 0.29, 0.82; P = .007] than DS. Technical success [OR: 0.62; 95% CI: 0.31, 1.25] and the length of hospital stay [MD: -2.12; 95% CI: -5.23, 0.98] were comparable between the 2 groups.

CONCLUSION

EUS-GE is associated with higher clinical success, longer total procedural time, lower re-intervention rate, and lower risk of adverse events than DS. Technical success and the length of hospital stay were comparable between the 2 groups. EUS-GE appears to be a safe and effective procedure for managing GOO. Further large, multicentric randomized controlled trials are warranted to investigate the safety and outcomes of EUS-GE in patients with malignant GOO.

Potential of Carbohydrate Antigen 19-9 and Serum Apolipoprotein A2-Isoforms in the Diagnosis of Stage 0 and IA Pancreatic Cancer

Apolipoprotein A2-ATQ/AT (apoA2-ATQ/AT) is a new biomarker for diagnosing pancreatic cancer (PC). In this study, the value of blood carbohydrate antigen 19-9 (CA19-9) and apoA2-ATQ/AT levels in diagnosing stage 0 and IA PC was evaluated. During 2014-2021, 12 patients with stage 0 PC and 12 patients with IA PC (average age: 73.8 years) underwent resection at JA Onomichi General Hospital. In addition, the data of 200 healthy controls were collected from a community-based cohort study. Levels of two apoA2-isoforms were measured using enzyme-linked immunosorbent assay (ELISA) with specific antibodies to calculate the apoA2-i Index as a surrogate value for apoA2-ATQ/AT. The cutoff value for the apoA2-i Index was determined to be 62.9 μg/mL. CA19-9 levels were also measured through ELISA. Among all 24 patients with PC, the positivity rates for apoA2-i and CA19-9 were 33.3% and 25.0%, respectively. The positivity rates for apoA2-i and CA19-9 were 16.7% and 8.3% in patients with stage 0 PC and 50.0% and 41.7% in those with stage IA, respectively. For CA19-9-negative patients, the apoA2-i positivity rate was 9.1% in stage 0 and 42.9% in stage IA. The combined positivity rate for both markers was 16.7% in stage 0 and 66.7% in stage IA. Imaging findings in apoA2-i- and CA19-9-positive patients included pancreatic duct dilatation (87.5%/100%), duct stenosis (75.0%/50%), and atrophy (87.5%/66.7%). The imaging findings of this study suggest that apoA2-i may enhance the sensitivity for detecting CA19-9-negative stage 0 and IA PC, and complementary measurements with CA19-9 may be valuable for diagnosing early-stage PC. Therefore, minute PC with pancreatic duct dilation, duct stenosis, and atrophy may exhibit a high positivity rate, aiding differential diagnosis.

Temporary mesenteric venous shunting for portal vein reconstruction: A novel technical adjunct

Pancreatic resection not infrequently requires portal vein (PV) repair or replacement. PV reconstruction often requires bypass grafting or patch venoplasty, and these grafts and patches require time to thaw or harvest. Mesenteric ischemia and congestion with associated bowel edema may result from prolonged venous occlusion during thawing, harvesting, and reconstructing. Temporary shunting of the mesenteric venous circulation may mitigate these adverse effects. Twenty-one patients were shunted using Argyle shunts during PV reconstruction from 2010 to 2020. Reconstructions in this series consisted of aortic homograft interposition grafts (52%), bovine pericardial patches (38%), internal jugular vein interposition grafts (5%), and internal jugular patches (5%). No intraoperative complications resulted from shunt placement; technical success of PV reconstruction was 100%. Temporary venous shunting during PV reconstruction is safe, technically straightforward, and may serve to decrease the duration of venous mesenteric occlusion.

Endoscopic ultrasound-guided gastroenterostomy versus enteral stenting for gastric outlet obstruction: a systematic review and meta-analysis

Background

The symptoms of gastric outlet obstruction have traditionally been managed surgically or endoscopically. Enteral stenting (ES) is a less invasive endoscopic treatment strategy for this condition. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) has recently become a potential alternative technique.

Objectives

We conducted a systematic review and meta-analysis of the effectiveness and safety profile of EUS-GE compared with ES.

Design

Meta-analysis and systematic review.

Data sources and methods

We searched multiple databases from inception to August 2023 to identify studies that reported the effectiveness and safety of EUS-GE compared with ES. The outcomes of technical success, clinical success, and adverse events (AEs) were evaluated. Pooled proportions were calculated using both fixed and random effects models.

Results

We included 13 studies with 1762 patients in our final analysis. The pooled rates of technical success for EUS-GE were 95.59% [95% confidence interval (CI), 94.01-97.44, I 2 = 32] and 97.96% (95% CI, 96.06-99.25, I 2 = 63) for ES. The pooled rate of clinical success for EUS-GE was 93.62% (95% CI, 90.76-95.98, I 2 = 54) while for ES it was lower at 85.57% (95% CI, 79.63-90.63, I 2 = 81). The pooled odds ratio (OR) of clinical success was higher for EUS-GE compared to ES at 2.71 (95% CI, 1.87-3.93). The pooled OR of clinical success for EUS-GE was higher compared to ES at 2.72 (95% CI, 1.86-3.97, I 2 = 0). The pooled rates of re-intervention for EUS-GE were lower at 3.77% (95% CI, 1.77-6.46, I 2 = 44) compared with ES, which was 25.13% (95% CI, 18.96-31.85, I 2 = 69). The pooled OR of the rate of re-intervention in the ES group was higher at 7.96 (95% CI, 4.41-14.38, I 2 = 13). Overall, the pooled rate for AEs for EUS-GE was 8.97% (95% CI, 6.88-11.30, I 2 = 15), whereas that for ES was 19.63% (95% CI, 11.75-28.94, I 2 = 89).

Conclusion

EUS-GE and ES are comparable in terms of their technical effectiveness. However, EUS-GE has demonstrated improved clinical effectiveness, a lower need for re-intervention, and a better safety profile compared to ES for palliation of gastric outlet obstruction.

Comparative Assessment of Endoscopic Ultrasound-Guided Biopsies vs. Percutaneous Biopsies of Pancreatic Lesions: A Systematic Review and Meta-Analysis of Diagnostic Performance

Introduction: Pancreatic cancer ranks as the fourth deadliest form of cancer. However, it is essential to note that not all pancreatic masses signal primary malignancy. Therefore, it is imperative to establish the correct differential diagnosis, a process further supported by pre-operative biopsy procedures. This meta-analysis aims to compare the diagnostic performance of two minimally invasive biopsy approaches for pancreatic tissue sampling: percutaneous biopsies guided by computed tomography or ultrasound, and transduodenal biopsies guided by endoscopic ultrasound (EUS). Methods: A systematic literature search was conducted in the MEDLINE and Scopus databases. The included studies analyzed the diagnostic performance of the two biopsy methods, and they were assessed for risk of bias using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Statistical analysis was carried out using the RevMan and MetaDisc software packages. Results: The statistical analysis of the results demonstrated the superiority of the percutaneous approach. Specifically, the pooled sensitivity, specificity, LR+, LR-and DOR for the percutaneous approach were 0.896 [95% CI: 0.878-0.913], 0.949 [95% CI: 0.892-0.981], 9.70 [95% CI: 5.20-18.09], 0.20 [95% CI: 0.12-0.32] and 68.55 [95% CI: 32.63-143.98], respectively. The corresponding values for EUS-guided biopsies were 0.806 [95% CI: 0.775-0.834], 0.955 [95% CI: 0.926-0.974], 12.04 [95% CI: 2.67-54.17], 0.24 [95% CI: 0.15-0.39] and 52.56 [95% CI: 13.81-200.09], respectively. Nevertheless, it appears that this statistical superiority is also linked to the selection bias favoring larger and hence more readily accessible tumors during percutaneous biopsy procedures. Conclusions: Concisely, our meta-analysis indicates the statistical superiority of the percutaneous approach. However, selecting the optimal biopsy method is complex, influenced by factors like patient and tumor characteristics, clinical resources, and other relevant considerations.

Pancreatic Juice-Derived microRNA-4516 and microRNA-4674 as Novel Biomarkers for Pancreatic Ductal Adenocarcinoma

Background and Aims

Precise diagnostic biomarkers are urgently required for pancreatic ductal adenocarcinoma (PDAC). Therefore, the aim of this study was to identify PDAC-specific exosomal microRNAs (Ex-miRs) from pancreatic juice (PJ) and evaluate their diagnostic potential.

Methods

Exosomes in PJ and serum were extracted using ultracentrifugation and confirmed morphologically and biochemically. PDAC-specific Ex-miRs were identified using our original miR arrays, in which "Ex-miRs derived from the PJ of patients with chronic pancreatitis (CP)" were subtracted from Ex-miRs commonly expressed in both "human PDAC cell lines" and "the PJ of patients with PDAC." We verified the expression of these miRs using quantitative real-time reverse transcription polymerase chain reaction. Changes in serum Ex-miR levels were assessed in 2 patients with PDAC who underwent curative resection. In situ hybridization was performed to directly visualize PDAC-specific miR expression in cancer cells.

Results

We identified novel Ex-miR-4516 and Ex-miR-4674 from the PJ of patients with PDAC, and they showed 80.0% and 81.8% sensitivity, 80.8% and 73.3% specificity, and 90.9% and 80.8% accuracy, respectively. The sensitivity, specificity, and accuracy of a triple assay of Ex-miR-4516/4674/PJ cytology increased to 93.3%, 81.8%, and 88.5%, respectively. In serum samples (n = 88), the sensitivity, specificity, and accuracy of Ex-miR-4516 were 97.5%, 34.3%, and 68%, respectively. Presurgical levels of serum-derived Ex-miR-4516 in 2 patients with relatively early disease stages declined after curative resection. In situ hybridization demonstrated that Ex-miR-4516 expression exclusively occurred in cancer cells.

Conclusion

Liquid assays using the in situ-proven Ex-miR-4516 may have a high potential for detecting relatively early-stage PDAC and monitoring its clinical course.

Molecular pathway of pancreatic cancer-associated neuropathic pain

The pancreas is a heterocrine gland that has both exocrine and endocrine parts. Most pancreatic cancer begins in the cells that line the ducts of the pancreas and is called pancreatic ductal adenocarcinoma (PDAC). PDAC is the most encountered pancreatic cancer type. One of the most important characteristic features of PDAC is neuropathy which is primarily due to perineural invasion (PNI). PNI develops tumor microenvironment which includes overexpression of fibroblasts cells, macrophages, as well as angiogenesis which can be responsible for neuropathy pain. In tumor microenvironment inactive fibroblasts are converted into an active form that is cancer-associated fibroblasts (CAFs). Neurotrophins they also increase the level of Substance P, calcitonin gene-related peptide which is also involved in pain. Matrix metalloproteases are the zinc-associated proteases enzymes which activates proinflammatory interleukin-1β into its activated form and are responsible for release and activation of Substance P which is responsible for neuropathic pain by transmitting pain signal via dorsal root ganglion. All the molecules and their role in being responsible for neuropathic pain are described below.

Radiation-Activated Cobalamin-Kinase Inhibitors for Treatment of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most dismal diagnoses that a patient can receive. PDAC is extremely difficult to treat, as drug delivery is challenging in part due to the lack of vascularization, high stromal content, and high collagen content of these tumors. We have previously demonstrated that attaching drugs to the cobalamin scaffold provides selectivity for tumors over benign cells due to a high vitamin demand in these rapidly growing cells and an overexpression of transcobalamin receptors in a variety of cancer types. Importantly, we have shown the ability to deliver cobalamin derivatives to orthotopic pancreas tumors. Tyrosine kinase inhibitors have shown promise in treating PDAC as well as other cancer types. However, some of these inhibitors suffer from drug resistance, and as such, their success has been diminished. With this in mind, we synthesized the tyrosine kinase inhibitors erlotinib (EGFR) and dasatinib (Src) that are attached to this cobalamin platform. Both of these cobalamin-drug conjugates cause visible light-induced apoptosis, and the cobalamin-erlotinib conjugate (2) causes X-ray-induced apoptosis in MIA PaCa-2 cells. Both visible light and X-rays provide spatial control of drug release; however, utilizing X-ray irradiation offers the advantage of deeper tissue penetration. Therefore, we explored the utilization of 2 as a synergistic therapy with radiation in athymic nude mice implanted with MIA PaCa-2 tumors. We discovered that the addition of 2 caused an enhanced reduction in tumor margins in comparison with radiation therapy alone. In addition, treatment with 2 in the absence of radiation caused no significant reduction in tumor size in comparison with the controls. The cobalamin technology presented here allows for the spatial release of drugs in conjunction with external beam radiation therapy, potentially allowing for more effective treatment of deep-seated tumors with less systemic side effects.

Elucidating the Role of miRNA-326 Modulating Hedgehog Signaling in Pancreatic Carcinoma

BACKGROUND AND AIM

Pancreatic ductal adenocarcinoma (PDAC) is one of the lethal malignancies worldwide characterized by poor prognosis. MicroRNAs (miRNAs) function as the key regulators in carcinogenesis and may act as noninvasive biomarkers in various malignancies including PDAC. The present study aimed to elucidate the role of miR-326, a known modulator of hedgehog (Hh) pathway in PDAC.

MATERIALS AND METHODS

miR-326 circulating levels were assessed in 105 PDAC patients, 31 with chronic pancreatitis (CP) and 36 healthy controls by quantitative Polymerase chain reaction. The expression of miR-326 and smoothened (SMO) was checked in surgical PDAC tissue. SMO protein expression was analyzed by immunohistochemistry in different groups. Finally, the role of miR-326 as a modulator of Hh pathway was assessed in vitro.

RESULTS

Our results demonstrate that miR-326 is downregulated in both blood and tissue of PDAC patients as compared with controls. In contrast, the target gene/protein expression of SMO is upregulated in PDAC. Moreover, the tumor stromal expression of SMO was found to be clinically associated with lymph-node metastasis and vascular encasement in PDAC. Overexpression of miR-326 in Panc1 cell line was found to induce downregulation of SMO suggesting the tumor suppressor role of miR-326 in PDAC.

CONCLUSIONS

Taken together, miR-326 acts as a tumor suppressor in PDAC by modulating Hh pathway. It may be a promising target for the development of efficient drug therapies for the treatment of PDAC.

Molecular Insights of MAP4K4 Signaling in Inflammatory and Malignant Diseases

Mitogen-activated protein kinase (MAPK) cascades are crucial in extracellular signal transduction to cellular responses. The classical three-tiered MAPK cascades include signaling through MAP kinase kinase kinase (MAP3K) that activates a MAP kinase kinase (MAP2K), which in turn induces MAPK activation and downstream cellular responses. The upstream activators of MAP3K are often small guanosine-5'-triphosphate (GTP)-binding proteins, but in some pathways, MAP3K can be activated by another kinase, which is known as a MAP kinase kinase kinase kinase (MAP4K). MAP4K4 is one of the widely studied MAP4K members, known to play a significant role in inflammatory, cardiovascular, and malignant diseases. The MAP4K4 signal transduction plays an essential role in cell proliferation, transformation, invasiveness, adhesiveness, inflammation, stress responses, and cell migration. Overexpression of MAP4K4 is frequently reported in many cancers, including glioblastoma, colon, prostate, and pancreatic cancers. Besides its mainstay pro-survival role in various malignancies, MAP4K4 has been implicated in cancer-associated cachexia. In the present review, we discuss the functional role of MAP4K4 in malignant/non-malignant diseases and cancer-associated cachexia and its possible use in targeted therapy.

Correlation between hypoxia and HGF/c-MET expression in the management of pancreatic cancer

Pancreatic cancer (PC) is very deadly and difficult to treat. The presence of hypoxia has been shown to increase the probability of cancer developing and spreading. Pancreatic ductal adenocarcinoma (PDAC/PC) has traditionally viewed a highly lethal form of cancer due to its high occurrence of early metastases. Desmoplasia/stroma is often thick and collagenous, with pancreatic stellate cells as the primary source (PSCs). Cancer cells and other stromal cells interact with PSCs, promoting disease development. The hepatocyte growth factor (HGF)/c-MET pathway have been proposed as a growth factor mechanism mediating this interaction. Human growth factor (HGF) is secreted by pancreatic stellate cells (PSCs), and its receptor, c-MET, is generated by pancreatic cancer cells and endothelial cells. Hypoxia is frequent in malignant tumors, particularly pancreatic (PC). Hypoxia results from limitless tumor development and promotes survival, progression, and invasion. Hypoxic is becoming a critical driver and therapeutic target of pancreatic cancer as its hypoxia microenvironment is defined. Recent breakthroughs in cancer biology show that hypoxia promotes tumor proliferation, aggressiveness, and therapeutic resistance. Hypoxia-inducible factors (HIFs) stabilize hypoxia signaling. Hypoxia cMet is a key component of pancreatic tumor microenvironments, which also have a fibrotic response, that hypoxia, promotes and modulates. c-Met is a tyrosine-protein kinase. As describe it simply, the MET gene in humans' codes for a protein called hepatocyte growth factor receptor (HGFR). Most cancerous tumors and pancreatic cancer in particular, suffer from a lack of oxygen (PC). Due to unrestrained tumor development, hypoxia develops, actively contributing to tumor survival, progression, and invasion. As the processes by which hypoxia signaling promotes invasion and metastasis become clear, c-MET has emerged as an important determinant of pancreatic cancer malignancy and a potential pharmacological target. This manuscript provides the most current findings on the role of hypoxia and HGF/c-MET expression in the treatment of pancreatic cancer.

Endoscopic ultrasound-guided balloon-occluded gastrojejunostomy bypass, duodenal stent or laparoscopic gastrojejunostomy for unresectable malignant gastric outlet obstruction

OBJECTIVES

Malignant gastric outlet obstruction (GOO) can be relieved by either laparoscopic gastrojejunostomy (LGJ), endoscopic stenting (SEMS) or endoscopic ultrasound-guided gastrojejunostomy (endoscopic ultrasound-guided balloon-occluded gastrojejunostomy bypass; EPASS). This study aimed to compare the outcomes of the three treatment methods.

METHODS

This was a retrospective study of patients who suffered from malignant GOO between January 2012 to November 2020 that received either EPASS, LGJ or SEMS. The outcomes included the technical and clinical success, 30-day adverse events and mortality, pre and post stenting GOO scores (GOOSs), stent patency and causes of stent dysfunction.

RESULTS

One hundred and fourteen patients were included (30 EPASS, 35 LGJ, 49 SEMS). The technical success of EPASS, LGJ and SEMS were 93.3%, 100%, 100% (P = 0.058) and clinical success rates were 93.3%, 80%, 87.8% (P = 0.276), respectively. Procedural time was longest for the LGJ group (P < 0.001). The EPASS group had the shortest hospital stay (EPASS 1.5 [1-17], LGJ 7 [2-44], SEMS 5 [2-46] days, P < 0.001). EPASS group also had the lowest rates of recurrent obstruction (EPASS 3.3%, LGJ 17.1%, SEMS 36.7%, P = 0.002) and re-intervention (EPASS 3.3%, LGJ 17.1%, SEMS 26.5%, P = 0.031). The 1-month GOOS was highest in the EPASS group (EPASS 3 [1-3], LGJ 3 [0-3], SEMS 2 [0-3], P = 0.028).

CONCLUSION

Endoscopic ultrasound-guided gastrojejunostomy was associated with better clinical outcomes then the other two procedures. The procedure may be the best option provided that the expertise is available.

Inhibition of lysosomal acid β-glucosidase induces cell apoptosis via impairing mitochondrial clearance in pancreatic cancer

Sphingolipid metabolism plays an important role in the formation of cellular membranes and is associated with malignant potential and chemosensitivity of cancer cells. Sphingolipid degradation depends on multiple lysosomal glucosidases. We focused on acid β-glucosidase (GBA), a lysosomal enzyme the deficiency of which is related to mitochondrial dysfunction. We analyzed the function of GBA in pancreatic ductal adenocarcinoma (PDAC). Human PDAC cell lines (PANC-1, BxPC-3 and AsPC-1) were examined under conditions of GBA knockdown via the short interfering RNA (siRNA) method. We assessed the morphological changes, GBA enzyme activity, GBA protein expression, cell viability, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) and mitophagy flux of PDAC cells. The GBA protein level and enzyme activity differed among cell lines. GBA knockdown suppressed cell proliferation and induced apoptosis, especially in PANC-1 and BxPC-3 cells, with low GBA enzyme activity. GBA knockdown also decreased the MMP and impaired mitochondrial clearance. This impaired mitochondrial clearance further induced dysfunctional mitochondria accumulation and ROS generation in PDAC cells, inducing apoptosis. The antiproliferative effects of the combination of GBA suppression and gemcitabine were higher than those of gemcitabine alone. These results showed that GBA suppression exerts a significant antitumor effect and may have therapeutic potential in the clinical treatment of PDAC.

Impact of radiologic splenic vessel invasion in resectable left-sided pancreatic ductal adenocarcinoma: predictor of early systemic recurrence following upfront surgery

BACKGROUND

The aim of this study is to identify prognostic factors and the best candidates for neoadjuvant therapy among patients with resectable left-sided pancreatic ductal adenocarcinoma (PDAC) by analyzing the timing and pattern of recurrence following upfront surgery.

METHODS

This single-center retrospective study included patients with resectable left-sided PDAC who underwent upfront distal pancreatectomy from 2005 to 2015. A minimum P value approach was used to evaluate the optimal cutoff of early recurrence. The predictors of recurrence were assessed with Cox regression analysis.

RESULTS

Among 311 included patients, 241 (77.5%) had a recurrence at a median follow-up of 29.3 months. Systemic recurrence occurred in 194 patients (80.5%) and isolated local recurrence in 47 patients (19.5%). A recurrence-free survival cutoff of 12 months was selected to distinguish between early and late recurrence. The patients with early recurrence had a shorter median overall survival (16.1 vs. 39.9 months, P<0.001) and post-recurrence survival (9.6 vs. 17.2 months, P<0.001) than those with late recurrence. The patients with systemic recurrence had a shorter median overall survival (19.6 vs. 29.1 months, P=0.007) and post-recurrence survival (11.0 vs. 15.3 months, P=0.024) than those with an isolated local recurrence. In multivariable analysis, preoperative CA 19-9 ≥500 U/mL [odd ratio (OR) 2.037, P=0.035], radiologic splenic vessels invasion (OR 5.014, P<0.001), positive radial resection margin (OR 2.638, P<0.001), and no adjuvant chemotherapy (OR 2.084, P=0.001) were predictors of an early systemic recurrence.

CONCLUSIONS

Radiologic splenic vessels invasion may be considered to indicate a biologically borderline status in patients with anatomically resectable left-sided PDAC. Future clinical trials of neoadjuvant therapy targeting these patients should be conducted.

Endoscopic approach in the diagnosis of high-grade pancreatic intraepithelial neoplasia

Early diagnosis of pancreatic ductal adenocarcinoma (PDAC) is essential for improving prognosis; however, diagnosing PDAC at an early stage is challenging. In patients with localized high-grade pancreatic intraepithelial neoplasia (HG-PanIN), whose tumorous lesion is undetectable on cross-sectional images such as computed tomography or magnetic resonance image, long-term survival is expected. Pancreatic cystic lesions or main pancreatic duct (MPD) dilatation are important indirect findings for the initial diagnosis of HG-PanIN. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS) should play important roles in detecting abnormal image findings, such as local irregular MPD stenosis, caliber MPD changes, small cystic lesions, or branch duct dilatation. Additionally, EUS could detect hypoechoic areas around the MPD stenosis in some patients with HG-PanIN. Subsequently, endoscopic retrograde cholangiopancreatography (ERCP) and its associated pancreatic juice cytology, including serial pancreatic juice aspiration cytologic examination (SPACE) after placement of an endoscopic nasopancreatic drainage (ENPD) tube, may have high diagnostic accuracy for confirming the malignancy in HG-PanIN. Although ERCP and its associated pancreatic cytology, including SPACE, may be associated with post-ERCP pancreatitis (PEP), a recent randomized trial suggested that a 4-Fr ENPD tube may reduce the incidence of PEP. In the future, further prospective multicenter studies are required to establish a standard method of SPACE. Additionally, further studies for novel biomarkers could help to establish evolutionary methods with duodenal fluid and pancreatic juice for the early and accurate diagnosis of early-stage PDAC.

Analysis of N6-methyladenosine-related lncRNAs in the tumor immune microenvironment and their prognostic role in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a rare solid malignancy with a poor prognosis. N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) play essential roles in tumorigenesis and progression. However, little is known about the role of m6A-related lncRNAs in PC.

METHODS

m6A-related lncRNAs were extracted by Pearson analysis, and then prognosis-related lncRNAs were filtered from the m6A-related lncRNAs by univariate Cox regression analysis. Based on the expression patterns of the prognosis-related lncRNAs, samples were classified into distinct clusters. Least absolute shrinkage and selection operator (LASSO) Cox regression was used to construct a m6A-lncRNA-related prognostic signature for PC patients. Receiver operating characteristic (ROC) curves and the corresponding area under the curve (AUC) values were used to evaluate the prognostic ability of the model.

RESULTS

A total of 178 tumor and 4 normal samples were extracted from The Cancer Genome Atlas (TCGA) database in our study. Based on the expression of 12 filtered prognosis-related lncRNAs, two distinct clusters were eventually identified; these clusters were characterized by differences in the tumor immune microenvironment (TIME) and prognosis. A risk model comprising ten m6A-related lncRNAs was identified as an independent predictor of prognosis. ROC analysis revealed that this model had an acceptable prognostic value for PC patients. The prognostic signature was related to the TIME and the expression of critical immune checkpoint molecules.

CONCLUSION

This study comprehensively assessed the expression pattern and prognostic value of m6A-related lncRNAs in PC. The different clusters correlated with distinct TIMEs and prognoses. The study also constructed a ten-gene signature prognostic model based on m6A-related lncRNAs, which showed good accuracy in predicting overall survival.

Endoscopic ultrasound-guided gastroenterostomy versus surgical gastrojejunostomy for the palliation of gastric outlet obstruction in patients with peritoneal carcinomatosis

BACKGROUND : Gastric outlet obstruction (GOO) with peritoneal carcinomatosis presents a technical challenge. Surgical gastrojejunostomy (SGJ) or enteral stenting have been the standard of care; however, endoscopic ultrasound-guided gastroenterostomy (EUS-GE) has emerged as a favorable alternative. Few data exist that compare these techniques in the setting of peritoneal carcinomatosis. METHODS : This single-center retrospective cohort study included 25 EUS-GE and 27 SGJ consecutive patients. Baseline demographics, cancer diagnosis and stage, clinical and technical success, adverse events, and obstruction recurrence data were collected. The primary outcome was the technical success comparison; secondary outcome was the adverse event rate comparison. Rates were compared with standard statistical tests. RESULTS : Mean age, obstruction location, and symptoms were similar between the groups. The EUS-GE group had more advanced disease (clinical stage 4, 100 % vs. 67 %; P = 0.006) and higher American Society of Anesthesiologists classification (class 3-4, 92 % vs. 50 %; P = 0.004). The technical success rate was 100 % in both groups (P > 0.99) and the adverse event rate was lower for EUS-GE (8 % vs. 41 %; P = 0.01). Clinical success was 88 % for EUS-GE and 85 % for SGJ (P > 0.99) and recurrent obstruction was lower with EUS-GE (28 % vs. 41 %; P = 0.13). The EUS-GE group had shorter procedure duration, length of stay, and time to chemotherapy resumption than the SGJ group. CONCLUSIONS : Although the EUS-GE group was older, with more comorbidity and advanced stages, the technical success rate was similar to SGJ and it had significantly fewer adverse events. EUS-GE is a safe and effective option for the management of malignant GOO with peritoneal carcinomatosis.

Optimizing outcomes for EUS-guided gastroenterostomy: results of a Standardized Clinical Assessment and Management Plan (with video)

BACKGROUND AND AIMS

EUS-guided gastroenterostomy (EUS-GE) has emerged as an option for managing malignant gastric outlet obstruction (GOO). However, there is currently no standardized technique, and outcomes are variable with inconsistencies both within and across centers. The present study aims to develop and assess outcomes of a Standardized Clinical and Assessment Management Plan (SCAMP) for EUS-GE.

METHODS

A SCAMP was created by a multidisciplinary team to develop and optimize a systematic approach for EUS-GE. This is a single-center, prospective cohort study on patients undergoing EUS-GE for GOO, using the developed SCAMP. Baseline demographics, cancer diagnosis and stage, Eastern Cooperative Oncology Group (ECOG) performance score, clinical and technical success, adverse events (AEs), and obstruction recurrence were collected. Primary outcomes included technical and clinical success. Obstruction-free and overall survival were calculated and compared with Kaplan-Meier analysis.

RESULTS

Fifty patients underwent EUS-GE in accordance with the SCAMP. Mean age was 67 years, 54% were women, and pancreatic cancer represented the largest cancer type (51%). Technical success was 100% and clinical success 92%. AEs occurred in 2 patients (4%). Recurrent obstruction occurred in 16%, related to distal small-bowel obstruction from carcinomatosis. Estimated mean obstruction-free survival was 217 days. Median overall survival was 230 days among patients with ECOG scores 0 to 2 and 82 days for ECOG scores ≥3 (P = .008).

CONCLUSIONS

The standardized technique used was associated with high technical and clinical success and low rates of AEs, morbidity and procedure-related mortality. Adopting a similar uniform systematic approach may improve procedural outcomes and dissemination.

In Pancreatic Adenocarcinoma Alpha-Synuclein Increases and Marks Peri-Neural Infiltration

α-Synuclein (α-syn) is a protein involved in neuronal degeneration. However, the family of synucleins has recently been demonstrated to be involved in the mechanisms of oncogenesis by selectively accelerating cellular processes leading to cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human cancers, with a specifically high neurotropism. The molecular bases of this biological behavior are currently poorly understood. Here, α-synuclein was analyzed concerning the protein expression in PDAC and the potential association with PDAC neurotropism. Tumor (PDAC) and extra-tumor (extra-PDAC) samples from 20 patients affected by PDAC following pancreatic resections were collected at the General Surgery Unit, University of Pisa. All patients were affected by moderately or poorly differentiated PDAC. The amount of α-syn was compared between tumor and extra-tumor specimen (sampled from non-affected neighboring pancreatic areas) by using in situ immuno-staining with peroxidase anti-α-syn immunohistochemistry, α-syn detection by using Western blotting, and electron microscopy by using α-syn-conjugated immuno-gold particles. All the methods consistently indicate that each PDAC sample possesses a higher amount of α-syn compared with extra-PDAC tissue. Moreover, the expression of α-syn was much higher in those PDAC samples from tumors with perineural infiltration compared with tumors without perineural infiltration.

Prevention of pancreatitis after stent implantation for distal malignant biliary strictures: systematic review and meta-analysis

INTRODUCTION

Biliary stent placement remains a palliative treatment for patients with unresectable distal malignant biliary strictures (DMBS). The incidence of post-ERCP-pancreatitis (PEP) significantly increases in patients receiving fully covered self-expandable metal stents (FCSEMS) who undergo endoscopic retrograde cholangiopancreatography (ERCP).

AREAS COVERED

This review provides an overview of prevention of PEP after stent implantation for DMBSs. The following operational variables were evaluated: (1) stent type (plastic or metal stent); (2) stent location (above or across the sphincter of Oddi); (3) prophylactic pancreatic duct stent placement; (4) endoscopic sphincterotomy (EST). PubMed, EMBASE, and Cochrane database were searched to identify eligible studies up to October 2021. The odds ratio (OR) with 95% confidence intervals (CI) were pooled using fixed- or random- effects models.

EXPERT OPINION

1. PEP occurs more frequently in DMBS patients with self-expandable metal stents (SEMS) compared to that plastic stent (PS). 2. The PEP incidence is higher in covered stents than that in uncovered self-expandable metal stents (USEMS), but not significantly. 3. PEP incidence increases in patients receiving transpapillary FCSEMS placement, particularly when there is an absence of pancreatic duct dilation, and prophylactic pancreatic stenting is recommended for these patients. 4. Limited studies with small sample indicate that there is no significant difference in PEP incidence between transpapillary and suprapapillary stents placement for DMBS. 5. Limited studies indicate that EST does not significantly affect the incidence of pancreatitis in DMBS patients.

Analysis of N6-Methyladenosine Modification Patterns and Tumor Immune Microenvironment in Pancreatic Adenocarcinoma

Background: Pancreatic adenocarcinoma (PAAD) is a rare cancer with a poor prognosis. N6-methyladenosine (m6A) is the most common mRNA modification. However, little is known about the relationship between m6A modification and the tumor immune microenvironment (TIME) in PAAD. Methods: Based on 22 m6A regulators, m6A modification patterns of PAAD samples extracted from public databases were systematically evaluated and correlated with the tumor immune and prognosis characteristics. An integrated model called the "m6Ascore" was constructed, and its prognostic role was evaluated. Results: Three different m6Aclusters and gene clusters were successively identified; these clusters were characterized by differences in prognosis, immune cell infiltration, and pathway signatures. The m6Ascore was constructed to quantify the m6A modifications of individual patients. Subsequent analysis revealed that m6Ascore was an independent prognostic factor of PAAD and could be a potential indicator to predict the response to immunotherapy. Conclusion: This study comprehensively evaluated the features of m6A modification patterns in PAAD. m6A modification patterns play a non-negligible role in the TIME of PAAD. m6Ascore provides a more holistic understanding of m6A modification in PAAD, and will help clinicians predict the prognosis and response to immunotherapy.

Novel Use of Hypoxia-Inducible Polymerizable Protein to Augment Chemotherapy for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies and is the fourth leading cause of cancer-related deaths in the United States. Unfortunately, 80-85% of patients are diagnosed with unresectable, advanced stage tumors. These tumors are incurable and result in a median survival less than approximately six months and an overall 5-year survival rate of less than 7%. Whilst chemotherapy is a critical treatment, cure is not possible without surgical resection. The poor clinical outcomes in PDAC can be partially attributed to its dense desmoplastic stroma, taking up roughly 80% of the tumor mass. The stroma surrounding the tumor disrupts the normal architecture of pancreatic tissue leading to poor vascularization, high intratumoral pressure along with hypoxia and an acidic tumor microenvironment. This complicated microenvironment presents a significant challenge for drug delivery. The current manuscript discusses a novel approach to overcome many of these various obstacles. A complex of gemcitabine (GEM) and hemoglobin S (HbS) was formulated, which self-polymerizes under hypoxic and acidic conditions. When polymerized, HbS has the potential to break the tumor stroma, decrease intratumoral pressure, and therefore improve the treatment efficacy of standard therapy. Intratumoral injection of HbS with a fluorescent small molecule surrogate for GEM into a pancreatic tumor xenograft resulted in improved dissemination of the small molecule throughout the pancreatic tumor. The self-polymerization of HbS + GEM was significantly more effective than either agent individually at decreasing tumor size in an in vivo PDAC mouse model. These findings would suggest a clinical benefit from delivering the complex of GEM and HbS via direct injection by endoscopic ultrasound (EUS). With such a treatment option, patients with locally advanced disease would have the potential to become surgical candidates, offering them a chance for cure.

Ethanol exposure of human pancreatic normal ductal epithelial cells induces EMT phenotype and enhances pancreatic cancer development in KC (Pdx1-Cre and LSL-KrasG12D ) mice

Alcohol is a risk factor for pancreatic cancer. However, the molecular mechanism by which chronic alcohol consumption influences pancreatic cancer development is not well understood. We have recently demonstrated that chronic ethanol exposure of pancreatic normal ductal epithelial cells (HPNE) induces cellular transformation by generating cancer stem cells (CSCs). Here, we examined whether chronic ethanol treatment induces epithelial–mesenchymal transition in HPNE cells and promotes pancreatic cancer development in KC (Pdx1‐Cre, and LSL‐Kras^G12D) mice. Our data demonstrate that chronic ethanol exposure of HPNE cells induces SATB2 gene and those cells became highly motile. Ethanol treatment of HPNE cells results in downregulation of E‐Cadherin and upregulation of N‐Cadherin, Snail, Slug, Zeb1, Nanog and BMI‐1. Suppression of SATB2 expression in ethanol‐transformed HPNE cells inhibits EMT phenotypes. KC mice fed with an ethanol‐containing diet show enhanced pancreatic cancer growth and development than those fed with a control diet. Pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of stem cell markers (CD133, CD44, CD24), pluripotency‐maintaining factors (cMyc, KLF4, SOX‐2, and Oct‐4), N‐Cadherin, EMT‐transcription factors (Snail, Slug, and Zeb1), and lower expression of E‐cadherin than those isolated from mice fed with a control diet. Furthermore, pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of inflammatory cytokines (TNF‐α, IL‐6, and IL‐8) and PTGS‐2 (COX‐2) gene than those isolated from mice fed with a control diet. These data suggest that chronic alcohol consumption may contribute to pancreatic cancer development by generating inflammatory signals and CSCs.

Reproducibility and prognostic significance of area of residual tumor (ART) in post-neoadjuvant resections of pancreatic ductal adenocarcinoma

BACKGROUND

The pathologic assessments of tumor response after neoadjuvant chemoradiotherapy (NACRT) are critical to improving the prognostic stratification for patients with pancreatic ductal adenocarcinoma (PDAC). Here we clarified the utility of our new grading system based on the area of residual tumor (ART) as compared to existing systems, such as the College of American Pathologists (CAP) and MD Anderson (MDA) score.

METHODS

Eight reviewers individually evaluated the tumor regression grade of 30 patients with PDAC based on three types of grading systems. The interobserver concordance and clinicopathological characteristics were compared between the three systems.

RESULTS

The interobserver concordance (kappa value) of the ART, CAP, and MDA score were 0.61, 0.48, and 0.53, respectively. Discrepant cases, which were 27% of the cases, exhibited smaller tumor and tumor bed sizes than concordant cases. The reduction in tumor size evaluated by microscopy showed a correlation with the rate of change in carcinoembryonic antigen (CEA) level, CA19-9 level, and tumor size on computed tomography (CT). The ART score was correlated with the tumor size on CT before and after NACRT and disease-free survival. The CAP and MDA scores were not associated with prognosis.

CONCLUSION

The ART grading system may be the most practical system to assess the tumor response in post-NACRT resections of PDAC.

Detailing the ultrastructure's increase of prion protein in pancreatic adenocarcinoma

BACKGROUND

Recent evidences have shown a relationship between prion protein (PrPc) expression and pancreatic ductal adenocarcinoma (PDAC). Indeed, PrPc could be one of the markers explaining the aggressiveness of this tumor. However, studies investigating the specific compartmentalization of increased PrPc expression within PDAC cells are lacking, as well as a correlation between ultrastructural evidence, ultrastructural morphometry of PrPc protein and clinical data. These data, as well as the quantitative stoichiometry of this protein detected by immuno-gold, provide a significant advancement in understanding the biology of disease and the outcome of surgical resection.

AIM

To analyze quantitative stoichiometry and compartmentalization of PrPc in PDAC cells and to correlate its presence with prognostic data.

METHODS

Between June 2018 and December 2020, samples from pancreatic tissues of 45 patients treated with pancreatic resection for a preoperative suspicion of PDAC at our Institution were collected. When the frozen section excluded a PDAC diagnosis, or the nodules were too small for adequate sampling, patients were ruled out from the present study. Western blotting was used to detect, quantify and compare the expression of PrPc in PDAC and control tissues, such as those of non-affected neighboring pancreatic tissue of the same patient. To quantify the increase of PrPc and to detect the subcellular compartmentalization of PrPc within PDAC cells, immuno-gold stoichiometry within specific cell compartments was analyzed with electron microscopy. Finally, an analysis of quantitative PrPc expression according to prognostic data, such as cancer stage, recurrence of the disease at 12 mo after surgery and recurrence during adjuvant chemotherapy was made.

RESULTS

The amount of PrPc within specimen from 38 out of 45 patients was determined by semi-quantitative analysis by using Western blotting, which indicates that PrPc increases almost three-fold in tumor pancreatic tissue compared with healthy pancreatic regions [242.41 ± 28.36 optical density (OD) vs 95 ± 17.40 OD, P < 0.0001]. Quantitative morphometry carried out by using immuno-gold detection at transmission electron microscopy confirms an increased PrPc expression in PDAC ductal cells of all patients and allows to detect a specific compartmentalization of PrPc within tumor cells. In particular, the number of immuno-gold particles of PrPc was significantly higher in PDAC cells respect to controls, when considering the whole cell (19.8 ± 0.79 particles vs 9.44 ± 0.45, P < 0.0001). Remarkably, considering PDAC cells, the increase of PrPc was higher in the nucleus than cytosol of tumor cells, which indicates a shift in PrPc compartmentalization within tumor cells. In fact, the increase of immuno-gold within nuclear compartment exceeds at large the augment of PrPc which was detected in the cytosol (nucleus: 12.88 ± 0.59 particles vs 5.12 ± 0.32, P < 0.0001; cytosol: 7.74. ± 0.44 particles vs 4.3 ± 0.24, P < 0.0001). In order to analyze the prognostic impact of PrPc, we found a correlation between PrPc expression and cancer stage according to pathology results, with a significantly higher expression of PrPc for advanced stages. Moreover, 24 patients with a mean follow-up of 16.8 mo were considered. Immuno-blot analysis revealed a significantly higher expression of PrPc in patients with disease recurrence at 12 mo after radical surgery (360.71 ± 69.01 OD vs 170.23 ± 23.06 OD, P = 0.023), also in the subgroup of patients treated with adjuvant CT (368.36 ± 79.26 OD in the recurrence group vs 162.86 ± 24.16 OD, P = 0.028), which indicates a correlation with a higher chemo-resistance.

CONCLUSION

Expression of PrPc is significantly higher in PDAC cells compared with control, with the protein mainly placed in the nucleus. Preliminary clinical data confirm the correlation with a poorer prognosis.

Context Matters-Why We Need to Change From a One Size Fits all Approach to Made-to-Measure Therapies for Individual Patients With Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers and remains a major unsolved health problem. While pancreatic ductal adenocarcinoma (PDAC) is associated with driver mutations in only four major genes (KRAS, TP53, SMAD4, and CDKN2A), every tumor differs in its molecular landscape, histology, and prognosis. It is crucial to understand and consider these differences to be able to tailor treatment regimens specific to the vulnerabilities of the individual tumor to enhance patient outcome. This review focuses on the heterogeneity of pancreatic tumor cells and how in addition to genetic alterations, the subsequent dysregulation of multiple signaling cascades at various levels, epigenetic and metabolic factors contribute to the oncogenesis of PDAC and compensate for each other in driving cancer progression if one is tackled by a therapeutic approach. This implicates that besides the need for new combinatorial therapies for PDAC, a personalized approach for treating this highly complex cancer is required. A strategy that combines both a target-based and phenotypic approach to identify an effective treatment, like Reverse Clinical Engineering® using patient-derived organoids, is discussed as a promising way forward in the field of personalized medicine to tackle this deadly disease.

A Wavelet-Based Learning Model Enhances Molecular Prognosis in Pancreatic Adenocarcinoma

Genome-wide omics technology boosts deep interrogation into the clinical prognosis and inherent mechanism of pancreatic oncology. Classic LASSO methods coequally treat all candidates, ignoring individual characteristics, thus frequently deteriorating performance with comparatively more predictors. Here, we propose a wavelet-based deep learning method in variable selection and prognosis formulation for PAAD with small samples and multisource information. With the genomic, epigenomic, and clinical cohort information from The Cancer Genome Atlas, the constructed five-molecule model is validated via Kaplan-Meier survival estimate, rendering significant prognosis capability on high- and low-risk subcohorts (p value < 0.0001), together with three predictors manifesting the individual prognosis significance (p value: 0.0012~0.024). Moreover, the performance of the prognosis model has been benchmarked against the traditional LASSO and wavelet-based methods in the 3- and 5-year prediction AUC items, respectively. Specifically, the proposed model with discrete stationary wavelet base (bior1.5) overwhelmingly outperformed traditional LASSO and wavelet-based methods (AUC: 0.787 vs. 0.782 and 0.721 for the 3-year case; AUC: 0.937 vs. 0.802 and 0.859 for the 5-year case). Thus, the proposed model provides a more accurate perspective, but with less predictor burden for clinical prognosis in the pancreatic carcinoma study.

Synchronous gastric cancer and carcinoma in situ of the pancreas

Abnormal findings in the pancreatic duct without a mass may require serial pancreatic juice aspiration cytological examination. In cases of synchronous gastric cancer and stage 0 pancreatic cancer, spleen-preserving pancreatectomy may have advantage.

Mitochondrial DNA and MitomiR Variations in Pancreatic Cancer: Potential Diagnostic and Prognostic Biomarkers

Pancreatic cancer is an aggressive disease with poor prognosis. Only about 15-20% of patients diagnosed with pancreatic cancer can undergo surgical resection, while the remaining 80% are diagnosed with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). In these cases, chemotherapy and radiotherapy only confer marginal survival benefit. Recent progress has been made in understanding the pathobiology of pancreatic cancer, with a particular effort in discovering new diagnostic and prognostic biomarkers, novel therapeutic targets, and biomarkers that can predict response to chemo- and/or radiotherapy. Mitochondria have become a focus in pancreatic cancer research due to their roles as powerhouses of the cell, important subcellular biosynthetic factories, and crucial determinants of cell survival and response to chemotherapy. Changes in the mitochondrial genome (mtDNA) have been implicated in chemoresistance and metastatic progression in some cancer types. There is also growing evidence that changes in microRNAs that regulate the expression of mtDNA-encoded mitochondrial proteins (mitomiRs) or nuclear-encoded mitochondrial proteins (mitochondria-related miRs) could serve as diagnostic and prognostic cancer biomarkers. This review discusses the current knowledge on the clinical significance of changes of mtDNA, mitomiRs, and mitochondria-related miRs in pancreatic cancer and their potential role as predictors of cancer risk, as diagnostic and prognostic biomarkers, and as molecular targets for personalized cancer therapy.

Prognostic impact of splenic vessel involvement and tumor size in distal pancreatectomy for adenocarcinoma: a retrospective multicentric cohort study

PURPOSE

Splenic vessel involvement occurs frequently in pancreatic ductal adenocarcinoma (PDAC) of the body and the tail (B/T) but the impact on survival is unknown. We assessed the influence of radiological and pathologic involvement of splenic artery (p-SA +) and vein (p-SV +) on patient outcomes after distal pancreatectomy (DP) for PDAC.

METHODS

From 2013 to 2019, all DP for PDAC in five centers were included. Factors associated with overall (OS) and disease-free (DFS) survival were identified.

RESULTS

Among the 76 patients included, 5 (6.6%) had p-SA + only, 11 (14.5%) had p-SV + only, and 24 (31.6%) had both p-SA + and p-SV + . The preoperative CT-scan accuracy to predict p-SV + and p-SA + was high (sensitivity: 91.4% and 82.8%, respectively; negative predictive value: 89.7% and 88.3%, respectively). The 5-year OS and DFS rates were 3.9% and 8.3%, respectively. Multivariate analysis identified splenic vessel involvement (i.e., p-SA + or p-SV + , or both p-SA + and p-SV +) as the only independent factor influencing DFS (HR 4.04; 95% CI [1.22-13.44], p = 0.023). Tumor size ≥ 30 mm was the only independent factor influencing OS (HR 4.04; 95% CI [1.26-12.95], p = 0.019) and was associated with a high risk of p-SA + (p = 0.001) and p-SV + (p < 0.001).

CONCLUSION

Tumor size ≥ 30 mm and splenic vessel involvement occurred in more than half of the patients who underwent DP for PDAC and had negative impact on long-term survival. Preoperative CT-scan was reliable to identify splenic vessel involvement in B/T PDAC. Large tumor size and radiological splenic vessel involvement could be taken into account to propose a neoadjuvant treatment.

Magic of a Common Sugar Pill in Cancer: Can Metformin Raise Survival in Pancreatic Cancer Patients?

Pancreatic cancer is one of the common cancers globally, with a poor survival outcome. Metformin, a popular anti-diabetic drug, has gained popularity for its use in the chemoprevention of cancer. However, results regarding the survival benefit of metformin in pancreatic cancer have been unpredictable. In this review, we aim to analyze the use of metformin in pancreatic cancer patients with pre-existing diabetes mellitus for survival benefit. We systematically conducted a literature search in PubMed, Science Direct, and Scopus databases to collect the relevant articles and reviewed them. Eventually, 11 quality appraised articles were included accessing overall survival as the primary outcome. Our results concluded that metformin can efficaciously improve survival in pancreatic cancer patients with coexisting diabetes mellitus, but the results are still incongruent. Hence, further prospective studies and clinical trials are essential to provide a strong evidence-based recommendation that will help prolong the lifespan of patients.

Cancer-associated fibroblasts are a useful cytological finding for diagnosing pancreatic ductal adenocarcinoma

INTRODUCTION

Cancer-associated fibroblasts (CAFs) are activated fibroblasts or myofibroblasts that play a crucial role in the invasiveness of pancreatic ductal adenocarcinoma (PDAC). In this study, the cytological features and diagnostic significance of CAFs based on pancreatic duct brushing cytology (PDBC) were evaluated.

METHODS

The prevalence of fibrous stroma (FS) including CAFs on PDBC in 42 PDAC cases and 33 benign cases was retrospectively investigated. The average nuclear size of fibroblasts was compared between PDAC and benign cases to distinguish CAFs from normal FS.

RESULTS

Overall, FS was observed in 25 PDAC cases (60%) and eight benign cases (24%). The average nuclear size of FS in PDAC cases was significantly larger than that in benign cases. From the receiver operating characteristics analysis, the cut-off value of the nuclear size of FS for the diagnosis of PDAC was defined as 10.22 µm. FS with nuclei over 10.22 µm in size in PDAC cases had clear prominent nucleoli. In contrast, FS in benign cases had no clear nucleoli. Thus, CAFs on PDBC were considered to be FS with nuclei over 10.22 µm in size and prominent nucleoli. The presence of CAFs on PDBC had 100% positive predictive value and specificity for the diagnosis of PDAC.

CONCLUSIONS

This study suggested that CAFs on PDBC could be distinguished from normal FS by large nuclear size (over 10.22 µm) and prominent nucleoli and that CAFs on PDBC may be used for the diagnosis of PDAC.

Intraperitoneal gemcitabine chemotherapy is safe for patients with resected pancreatic cancer: final clinical and pharmacologic data from a phase II protocol and recommended future directions

Worldwide, the surgical management of pancreas cancer using the Whipple procedure results in long-term survival in approximately 20% of patients when there is a R0 resection. Local recurrence within the resection site and peritoneal metastases are a prominent part of this treatment failure. Gemcitabine was used for a regional chemotherapy treatment strategy. Doses and schedules of chemotherapy routinely used for systemic treatment were administered as hyperthermic intraperitoneal chemotherapy (HIPEC) in the operating room. Then patients went on to receive 6 months of long-term normothermic intraperitoneal chemotherapy (NIPEC) with gemcitabine. Data was gathered to determine a pharmacologic rationale and safety of this monotherapy with gemcitabine. The use of intraperitoneal gemcitabine was well supported by pharmacologic data. The peritoneal surface exposure as measured by pharmacokinetic studies showed the area under the curve (AUC) of intraperitoneal concentration times time divided by plasma concentration times time to be 95-507. Regarding the safety of HIPEC gemcitabine in 12 patients, a single class III adverse event that resolved by radiologic intervention occurred. In patients with resected pancreas cancer treated with HIPEC gemcitabine the morbidity and mortality rate was not increased over historical data of resection alone. Also, six cycles of NIPEC gemcitabine were well tolerated in eight of eight eligible patients with seven patients completing 6 months of long-term intraperitoneal treatment. Local recurrence and peritoneal metastases were absent. Median survival was 29 months and five patients survived longer than 2 years. These early data suggest that intraperitoneal gemcitabine given under hyperthermic conditions in the operating theater and long-term through an intraperitoneal port is safe. Also, in this pilot study long-term local control with intraperitoneal gemcitabine occurred. Intraperitoneal gemcitabine may improve local-regional control of resected pancreas cancer. This may lead to more successful multimodality strategies.

Hyperthermic intra-operative intraperitoneal chemotherapy as an adjuvant to pancreatic cancer resection

Background

Even after potentially curative resection the long-term survival of pancreatic cancer is poor. The local-regional failures are frequent. Previous studies have shown that adjuvant treatment with hyperthermic intra-operative intraperitoneal chemotherapy (HIPEC) may effectively control local disease. The objective of the study is to update the results of the prior publications by integrating data from recently accrued cases. Also, to revisit the clinical and pharmacological rationale for the intraperitoneal administration of chemotherapy in pancreatic cancer patients undergoing potentially curative resection.

Methods

This is a prospective study of pancreatic cancer patients that underwent R₀ resection in combination with HIPEC-gemcitabine. Morbidity and mortality were recorded. Survival was calculated and the sites for recurrent disease were recorded.

Results

The updated results for 33 patients that underwent treatment until 2016 and for 6 more patients that were included until 2018 were presented. The hospital mortality and morbidity rate were 5.1% (2 patients), and 28.2% (11 patients) respectively. The median and 5-year survival rate was 17 months and 24% respectively. With a median follow-up time of 13 months 23 patients (59%) were recorded with recurrence. Local regional failures were recorded in 4 patients (10.3%).

Conclusions

HIPEC following R₀ resection is a feasible and safe adjuvant treatment for pancreatic cancer. The local-regional failures appear to be significantly decreased and to result in an increased overall survival. Further studies with combined intraperitoneal and systemic perioperative chemotherapy may serve to supplement our data with an increased benefit for patients having pancreas cancer resection.

Tumor innervation and clinical outcome in pancreatic cancer

Pancreatic cancer is a highly aggressive malignancy characterized by poor survival, recurrence after surgery and resistance to therapy. Nerves infiltrate the microenvironment of pancreatic cancers and contribute to tumor progression, however the clinicopathological significance of tumor innervation is unclear. In this study, the presence of nerves and their cross-sectional size were quantified by immunohistochemistry for the neuronal markers S-100, PGP9.5 and GAP-43 in a series of 99 pancreatic cancer cases versus 71 normal adjacent pancreatic tissues. A trend was observed between the presence of nerves in the tumor microenvironment of pancreatic cancer and worse overall patient survival (HR = 1.8, 95% CI 0.77-4.28, p = 0.08). The size of nerves, as measured by cross-sectional area, were significantly higher in pancreatic cancer than in the normal adjacent tissue (p = 0.002) and larger nerves were directly associated with worse patient survival (HR = 0.41, 95% CI 0.19-0.87, p = 0.04). In conclusion, this study suggests that the presence and size of nerves within the pancreatic cancer microenvironment are associated with tumor aggressiveness.

Comparison of the Diagnostic Efficiency of Radial- and Convex-Arrayed Echoendoscopes for Indirect Findings of Pancreatic Cancer: A Retrospective Comparative Study Using Propensity Score Method

Simple Summary

Pancreatic cancer (PC) has a poor prognosis; however, diagnosing PC at an earlier stage could improve long-term patient outcomes. Endoscopic ultrasonography (EUS) plays an important role in PC detection, and the indirect findings (caliber change, retention cysts, and dilatation of the branch duct) that are detected by EUS are especially important for the early detection of PC. The aim of this retrospective study was to compare the diagnostic efficacy of radial- and convex-arrayed echoendoscope for the detection rate of indirect findings. As a result, the radial-arrayed echoendoscope was found to be an independent detection factor of indirect findings by multivariate analysis. The radial-arrayed echoendoscope is useful for the detection of indirect findings.

Abstract

Endoscopic ultrasonography (EUS) is useful for detecting early-stage pancreatic cancer. Because the detection of small lesions is difficult, it is important to detect indirect findings, namely caliber change, retention cysts, and dilatation of the branch duct, during the procedure. Although two types of EUS endoscopes are frequently used, there is no comparative study on their efficacy for detecting indirect findings. Therefore, we aimed to compare the diagnostic efficacy of these two types for indirect findings. We retrospectively analyzed 316 consecutive patients who had undergone EUS for pancreaticobiliary disease at a single center between January 2017 and December 2018. The main outcome was the detection rate of indirect findings and its comparison between the two echoendoscope types. This outcome was achieved using the inverse probability of treatment weighting (IPTW) analysis. The detection rate of indirect findings was higher for the radial-arrayed endoscope than for the convex-arrayed echoendoscope (9.2% vs. 2.3% (p = 0.02)). The univariate analysis also revealed that the radial-arrayed echoendoscope was significantly superior to the convex-arrayed echoendoscope in terms of the detection of indirect findings (odds ratio, 5.94; 95% confidence interval, 1.68–21.10; p = 0.01) after IPTW. After adjustment for magnetic resonance imaging (MRI) and computed tomography (CT), radial-arrayed echoendoscope remained an independent factor for indirect finding detection (odds ratio, 6.04; 95% confidence interval, 1.74–21.00; p = 0.01). Finally, five patients who had indirect EUS findings were diagnosed with pancreatic cancer. Our results indicate that the radial-arrayed echoendoscope is useful for the detection of indirect findings.

EUS-guided gastroenterostomy versus enteral stenting for gastric outlet obstruction: Systematic review and meta-analysis

Background and study aims  Endoscopic and surgical techniques have been utilized for palliation of gastric outlet obstruction (GOO). Enteral stenting (ES) is an established technique with high clinical success and low morbidity rate. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is a novel approach that aims to provide sustained palliation of GOO. We conducted a comprehensive review and meta-analysis to evaluate the effectiveness in terms of clinical and technical success, as well as the safety profile of EUS-GE and ES. Methods  We searched multiple databases from inception through July 2020 to identify studies that reported on safety and effectiveness of EUS-GE in comparison to ES. Pooled rates of technical success, clinical success, and adverse events (AEs) were calculated. Study heterogeneity was assessed using I 2 % and 95 % confidence interval. Results  Five studies including 659 patients were included in our final analysis. Pooled rate of technical and clinical success for EUS-GE was 95.2 % (CI 87.2-.98.3, I 2  = 42) and 93.3 % (CI 84.4-97.3, I 2  = 59) while for ES it was 96.9 % (CI 90.9-99, I 2  = 64) and 85.6 % (CI 73-92.9, I 2  = 85), respectively. Pooled rate of re-intervention was significantly lower with EUS-GE i. e. 4 % (CI 1.8-8.7, I 2  = 35) compared to ES, where it was 23.6 % (CI 17.5-31, I 2  = 35), p = 0.001 . Pooled rates of overall and major AEs were comparable between the two techniques. Conclusion  EUS-GE is comparable in terms of technical and clinical effectiveness and has a similar safety profile when compared to ES for palliation of GOO.

Plasma suPAR may help to distinguish between chronic pancreatitis and pancreatic cancer

OBJECTIVES

SuPAR (soluble urokinase-type plasminogen activator receptor) is a biomarker reflecting the inflammatory state of the human body. Earlier studies suggest that urinary suPAR/creatinine ratio levels are elevated in chronic pancreatitis (CP), and that plasma suPAR (P-suPAR) level is elevated in pancreatic cancer (PC). Our aim was to study the levels of P-suPAR in CP in a long-term prospective follow-up setting to explore the possibility of distinguishing between PC and CP.

MATERIALS AND METHODS

Two patient groups were compared. The first group included 83 patients who were prospectively followed up after their first acute alcohol-induced pancreatitis (AAP) for median 7.0 (range 0.3-9.8) years. Twelve patients in this group developed CP during follow-up, and two patients were further excluded from the CP cohort. The second group consisted of 25 patients operated on for suspicion of pancreatic malignancy and final pathological diagnosis of PC. P-suPAR levels were measured and compared within and between these groups.

RESULTS

P-suPAR levels remained low during follow-up despite the development of CP. P-suPAR was significantly higher in PC patients [median 3.7 (IQR 3.1-4.4) ng/mL] than in CP patients [2.6 (1.8-3.6) ng/mL]; p = .014. A cutoff value of 2.8 ng/mL resulted from a ROC curve with area under curve (AUC) of 0.79 (95% CI 0.61-0.97), p = .009 in differentiation between PC and CP with a sensitivity and a specificity of 88% and 70% respectively.

CONCLUSION

P-suPAR is higher in patients with PC than in patients with CP, and it could thus be used in differentiating between PC and CP.

Endoscopic Ultrasonography Diagnosis of Early Pancreatic Cancer

Early diagnosis of pancreatic cancer (PC) can improve patients’ prognosis. We aimed to investigate the utility of endoscopic ultrasonography (EUS) for the early diagnosis of PC. This study included 64 patients with PC at an early stage treated at Onomichi General Hospital between January 2007 and January 2020. Diagnostic procedures included contrast computed tomography (CT), magnetic resonance cholangiopancreatography, EUS fine-needle aspiration, and endoscopic retrograde cholangiopancreatography (ERCP) for pancreatic juice cytology. The mean age was 71.3 years. In all, 32 patients were stage 0, and 32 were stage I. As for image findings, the main pancreatic duct (MPD) stenosis was detected in several cases, although CT and MRCP seldom detected tumors. EUS had a high detection rate for stage 0 tumor lesions. The median observation period was 3.9 years. In cases with stage 0, the 1 year and 5 year survival rates were 100% and 78.9%, respectively. In cases with stage I, the 1 year and 5 year survival rates were 96.4% and 66.7%, respectively. EUS has the highest sensitivity among all imaging modalities for detecting small pancreatic tumors. Cases with MPD dilation or stenosis, especially with tumors that cannot be identified on CT and MRI, should have EUS performed. In some cases, EUS was not able to detect any tumor lesions, and ERCP-based pancreatic juice cytology should be useful for pathological diagnosis.

Changing trends in the clinicopathological features, practices and outcomes in the surgical management for cystic lesions of the pancreas and impact of the international guidelines: Single institution experience with 462 cases between 1995-2018

INTRODUCTION

The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice.

METHODS

462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998-2006, 2007-2012 and 2013 to 2018.

RESULTS

Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HR^SG06 and HR^FG12 CLP with a corresponding lower proportion of LR^SG06 and LR^FG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated.

CONCLUSIONS

Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HR^SG06 and HR^FG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

NK cells in pancreatic cancer demonstrate impaired cytotoxicity and a regulatory IL-10 phenotype

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common tumor subtypes and remains associated with very poor survival. T cell infiltration into tumor tissue is associated with improved clinical outcome but little is known regarding the potential role of NK cells in disease control. Here we analyze the phenotype and function of NK cells in the blood and tumor tissue from patients with PDAC. Peripheral NK cells are present in normal numbers but display a CD16hiCD57hi phenotype with marked downregulation of NKG2D. Importantly, these cells demonstrate reduced cytotoxic activity and low levels of IFN-γ expression but instead produce high levels of intracellular IL-10, an immunoregulatory cytokine found at increased levels in the blood of PDAC patients. In contrast, NK cells are largely excluded from tumor tissue where they display strong downregulation of both CD16 and CD57, a phenotype that was recapitulated in primary NK cells following co-culture with PDAC organoids. Moreover, expression of activatory proteins, including DNAM-1 and NKP30, was markedly suppressed and the DNAM-1 ligand PVR was strongly expressed on tumor cells. As such, in situ and peripheral NK cells display differential features in patients with PDAC and indicate local and systemic mechanisms by which the tumor can evade immune control. These findings offer a number of potential options for NK-based immunotherapy in the management of patients with PDAC.

Objective assessment of tumor regression in post-neoadjuvant therapy resections for pancreatic ductal adenocarcinoma: comparison of multiple tumor regression grading systems

Neoadjuvant therapy is increasingly used to control local tumor spread and micrometastasis of pancreatic ductal adenocarcinoma (PDAC). Pathology assessments of treatment effects might predict patient outcomes after surgery. However, there are conflicting reports regarding the reproducibility and prognostic performance of commonly used tumor regression grading systems, namely College of American Pathologists (CAP) and Evans' grading system. Further, the M.D. Anderson Cancer Center group (MDA) and the Japan Pancreas Society (JPS) have introduced other grading systems, while we recently proposed a new, simple grading system based on the area of residual tumor (ART). Herein, we aimed to assess and compare the reproducibility and prognostic performance of the modified ART grading system with those of the four grading systems using a multicenter cohort. The study cohort consisted of 97 patients with PDAC who had undergone post-neoadjuvant pancreatectomy at four hospitals. All patients were treated with gemcitabine and S-1 (GS)-based chemotherapies with/without radiation. Two pathologists individually evaluated tumor regression in accordance with the CAP, Evans', JPS, MDA and ART grading systems, and interobserver concordance was compared between the five systems. The ART grading system was a 5-tiered system based on a number of 40× microscopic fields equivalent to the surface area of the largest ART. Furthermore, the final grades, which were either the concordant grades of the two observers or the majority grades, including those given by the third observer, were correlated with patient outcomes in each system. The interobserver concordance (kappa value) for Evans', CAP, MDA, JPS and ART grading systems were 0.34, 0.50, 0.65, 0.33, and 0.60, respectively. Univariate analysis showed that higher ART grades were significantly associated with shorter overall survival (p = 0.001) and recurrence-free survival (p = 0.005), while the other grading systems did not show significant association with patient outcomes. The present study revealed that the ART grading system that was designed to be simple and more objective has achieved high concordance and showed a prognostic value; thus it may be most practical for assessing tumor regression in post-neoadjuvant resections for PDAC.

The occurrence of prion protein in surgically resected pancreatic adenocarcinoma

BACKGROUND

Among the several new targets for the comprehension of the biology of pancreatic ductal adenocarcinoma (PDAC), Prion proteins (PrPc) deserve particular mention, since they share a marked neurotropism. Actually, PrPc could have also a role in tumorigenesis, as recently demonstrated. However, only few in vitro studies in cell cultures showed the occurrence of PrPc in PDAC cells. We aim to evaluate the presence of PrPc in vivo in PDAC tissues as a potential new biomarker.

METHODS

Samples from tumors of 23 patients undergone pancreatic resections from July 2018 to May 2020 at our institution were collected and analyzed. Immunohistochemistry and western blotting of PDAC tissues were compared with control tissues. Immunohistochemistry was used also to evaluate the localization of PrPc and of CD155, a tumoral stem-cell marker.

RESULTS

All cases were moderately differentiated PDAC, with perineural invasion (PNI) in 19/23 cases (83%). According to western-blot analysis, PrPc was markedly expressed in PDAC tissues (273.5 ± 44.63 OD) respect to controls (100 ± 28.35 OD, p = 0.0018). Immunohistochemistry confirmed these findings, with higher linear staining of PrPc in PDAC ducts (127.145 ± 7.56 μm vs 75.21 ± 5.01 μm, p < 0.0001). PrPc and CD155 exactly overlapped in ductal tumoral cells, highlighting the possible relationship of PrPc with cancer stemness. Finally, PrPc expression related with cancer stage and there was a potential correspondence with PNI.

CONCLUSIONS

Our work provides evidence for increased levels of PrPc in PDAC. This might contribute to cancer aggressiveness and provides a potentially new biomarker. Work is in progress to decipher clinical implications.

Value of CT-Guided Percutaneous Irreversible Electroporation Added to FOLFIRINOX Chemotherapy in Locally Advanced Pancreatic Cancer: A Post Hoc Comparison

PURPOSE

To compare survival after CT-guided percutaneous irreversible electroporation (IRE) and folinic acid, fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX) chemotherapy versus FOLFIRINOX only in patients with locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

A post hoc comparison was performed of data derived from a prospective IRE-FOLFIRINOX cohort and a retrospective FOLFIRINOX-only cohort. All patients received a minimum of 3 cycles of FOLFIRINOX for LAPC and were considered eligible for CT-guided percutaneous IRE. Endpoints included overall survival (OS), local and distant progression-free survival, and time to progression (TTP) and were compared using stratified Kaplan-Meier analysis. Patients who received > 8 cycles of FOLFIRINOX before IRE and who had tumors > 6 cm in the FOLFIRINOX-only group were excluded.

RESULTS

Of 103 patients with a diagnosis of LAPC, 52 were deemed eligible (n = 30 IRE-FOLFIRINOX and n = 22 FOLFIRINOX-only). Patients in the FOLFIRINOX-only arm had larger tumors (53 mm ± 19 vs 38 mm ± 7, P = .340), had more locoregional lymph node metastases (23% vs 7%, P = .622), and more often received radiotherapy (7 patients vs 2 patients, P = .027); all other baseline characteristics were comparable. Median OS was 17.0 months (range, 5-35 mo; SD = 6) for IRE-FOLFIRINOX versus 12.4 months (range, 3-22 mo; SD = 6) for FOLFIRINOX-only (P = .038). After sensitivity analyses, median OS was 17.2 months (range, 6-27 mo; SD = 6) versus 12.4 months (range, 7-32 mo; SD = 10) (P = .05). Median TTP was longer in the IRE-FOLFIRINOX group: 14.2 months (range, 5-25 mo; SD = 4) versus 5.2 months (range, 2-22; SD = 6) (P = .0001).

CONCLUSIONS

In patients with LAPC after FOLFIRINOX chemotherapy, CT-guided percutaneous IRE may improve OS and TTP. This study may facilitate the design of randomized controlled trials to compare survival after IRE-FOLRINOX versus FOLFIRINOX-only.

Validation of the clinical utility of 4 guidelines in the initial triage of mucinous cystic lesions of the pancreas based on cross-sectional imaging: Experience with 188 surgically-treated patients

INTRODUCTION

Over the years, several guidelines have been introduced to guide management of mucinous pancreatic cystic neoplasms (mPCN). In this study, we aimed to evaluate and compare the clinically utility of the Sendai-06, Fukuoka-12, Fukuoka-17 and European-18 guidelines in predicting malignancy of mPCN.

METHODS

One hundred and eighty-eight patients with mucinous cystic neoplasms (MCN) or intraductal papillary mucinous neoplasm (IPMN) who underwent surgery were retrospectively reviewed and classified under the 4 guidelines. Malignancy was defined as high grade dysplasia and invasive carcinoma.

RESULTS

Raised CA19-9>37U/ml, enhancing mural nodule≥5 mm and main pancreatic duct≥10 mm were significantly associated with malignancy on multivariate analysis. Increasing number of high risk features, absolute indications (European-18), worrisome risk or relative indications (European-18) were significantly associated with an increased likelihood of malignancy. The positive predictive values (PPV) of high risk features for Sendai-06, Fukuoka-12, Fukuoka-17 and absolute indications (European-18) for malignancy were 53%, 76%, 78% and 78% respectively. The negative predictive values (NPV) of the Sendai-06, Fukuoka-12 and Fukuoka-17 were 100%, while that of the European-18 was 92%. Risk of malignancy for patients with ≥4 worrisome features (Fukuoka-17) and ≥3 relative indications (European-18) was 66.7% and 75.0% respectively.

CONCLUSIONS

All 4 guidelines studied were useful in the initial triage of mPCN for the risk stratification of malignancy. The Fukuoka-17 had the highest PPV and NPV.

Overall Postoperative Morbidity and Pancreatic Fistula Are Relatively Higher after Central Pancreatectomy than Distal Pancreatic Resection: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare the intraoperative and postoperative outcomes of central pancreatectomy (CP) with distal pancreatectomy (DP).

METHODS

A systematic literature search was performed on electronic databases from MEDLINE, Embase, and PubMed from 1998 to 2018. Statistical analysis and meta-analysis were performed using statistics/data analysis (Stata®) software, version 12.0 (StataCorp LP, College Station, Texas 77845, USA). Dichotomous variables were analyzed by estimation of relative risk (RR) with a 95 percent (%) confidence interval (CI) and continuous variables were analyzed by standardized mean differences (SMD) with 95% CI.

RESULTS

Twenty-four studies with 593 CP and 1226 DP were included in the meta-analysis. CP had significantly longer operation time (SMD: 1.03; 95% CI 0.62 to 1.44; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.001) and lengthier postoperative hospital stay (SMD: 0.63; 95% CI 0.20 to 1.05; P < 0.01). Estimated blood loss was significantly lower in CP (SMD: -0.34; 95% CI -0.58 to -0.09; P = 0.007). Overall postoperative morbidity (RR: 1.30; 95% CI: 1.13 to 1.50; P < 0.001), overall pancreatic fistula (RR: 1.41; 95% CI: 1.20 to 1.66; P < 0.001), clinically relevant fistula (RR: 1.64; 95% CI: 1.25 to 2.16; P < 0.001), and postoperative hemorrhage (RR: 1.90; 95% CI: 1.18 to 3.06; P < 0.05) were all significantly higher after CP. On long-term follow-up, DP patients were more likely to have postoperative exocrine (RR: 0.56; 95% CI: 0.37 to 0.84; P < 0.05) and endocrine (RR: 0.27; 95% CI: 0.18 to 0.40; P < 0.001) insufficiency. There was no statistically significant difference in transfusion requirement, postoperative mortality, reoperation, and tumor recurrence.

CONCLUSION

CP is associated with significantly higher morbidity and clinically relevant pancreatic fistula. CP should only be reserved for selected patients who require postoperative pancreatic function preservation.