Hypoxia: a barricade to conquer the pancreatic cancer

Pancreatic cancer (PC) remains one of the most extremely lethal malignancies worldwide due to late diagnosis and early metastasis, with a 1-year overall survival rate of approximately 20%. The hypoxic microenvironment, induced by intratumoral hypoxia, promotes tumor invasion and progression, leading to chemotherapy or radiotherapy resistance and eventual mortality after treatment of PC. However, the role of the hypoxic microenvironment in PC is complicated and requires further investigation. In this article, we review recent advances regarding the regulation of malignant behaviors in PC, which provide insight into the potential of hypoxic microenvironment activation therapy for the therapeutic agents.

Classification of extrachromosomal circular DNA with a focus on the role of extrachromosomal DNA (ecDNA) in tumor heterogeneity and progression

Although the eukaryotic genome is mainly comprised of linear chromosomal DNA, genes can also be found outside of chromosomes. The unconventional presence of extrachromosomal genes is usually found to be circular, and these structures are named extrachromosomal circular DNA (eccDNA), which are often observed in cancer cells. Various types of eccDNA including small polydispersed DNA (spcDNA), telomeric cirlces, microDNA, etc. have been discovered. Among these eccDNA, extrachromosomal DNA (ecDNA), which encompasses the full spectrum of large, gene-containing extrachromosomal particles, has regained great research interest due to recent technological advances such as next-generation sequencing and super-resolution microscopy. In this review, we summarize the different types of eccDNA and discuss the role of eccDNA, especially ecDNA in tumor heterogeneity and progression. Additionally, we discuss some possible future investigative directions related to ecDNA biogenesis and its clinical application.

Tumor-Infiltrating Neutrophils Predict Poor Survival of Non-Functional Pancreatic Neuroendocrine Tumor

OBJECTIVE

This study retrospectively characterized the immune infiltrating profile in nonfunctional pancreatic neuroendocrine tumors (NF-PanNETs).

METHODS

Tumor tissues from the 109-patient Fudan cohort and a 73-patient external validation set were evaluated by immunohistochemistry for 9 immune cell types: tumor-infiltrating neutrophils (TINs), tumor-associated macrophages (TAMs), CD11c+ dendritic cells, anti-NCR1+ natural killer (NK) cells, CD4+ and CD8+ T cells, CD45RO+ memory T cells, FOXP3+ regulatory T cells (Tregs), and CD20+ B cells.

RESULTS

TINs were primarily distributed in the intratumoral area, dendritic cells and NK cells were scattered evenly in intratumoral and stromal areas, and Tregs were rarely detected. The remaining 5 cell types were primarily present in peritumoral stroma. Total TINs (P < .001) and TAMs (P = .002) increased as NF-PanNET grade rose. Kaplan-Meier analyses showed that high intratumoral TINs, total TAMs, and stromal CD4+ T-cell infiltration correlated with shorter recurrence-free survival (RFS, P = .010, P = .027, and P = .035, respectively) and overall survival (OS, P = .017, P = .029, and P = .045, respectively). Additionally, high intratumoral CD8+ T cell infiltration correlated with prolonged RFS (P = .039). Multivariate Cox regression demonstrated that intratumoral TINs, World Health Organization (WHO) classification, and eighth edition of the American Joint Committee on Cancer tumor-node-metastasis staging system (AJCC8th TNM) were independent factors for RFS (P = .043, P = .023, and P = .029, respectively), whereas intratumoral TINs and WHO classification were independent factors for OS (P = .010 and P = .007, respectively). Furthermore, the combination of TINs, WHO classification, and AJCC8th TNM remarkably improved prognostic accuracy for RFS. These results have been verified in the external validation set.

CONCLUSION

Intratumoral TINs are an independent and unfavorable predictor of postoperative NF-PanNETs. A combination of TINs, WHO classification, and AJCC8th TNM could improve prognostic accuracy for RFS.

Function and regulation of F-box/WD repeat-containing protein 7

The ubiquitin-proteasome system is an important post-translational modification system involved in numerous biological processes, such as cell cycle regulation, gene transcription, signal transduction, apoptosis, differentiation and development. F-box/WD repeat-containing protein 7 (FBXW7) is one of the most studied F-box (FBX) proteins, serving as substrate recognition component of S phase kinase-associated protein 1-Cullin 1-FBX protein complexes. As a tumor suppressor, FBXW7 recognizes numerous proto-oncoproteins and promotes their ubiquitination and subsequent proteasomal degradation. FBXW7 is regulated at different levels, leading to tunable and specific control of the activity and abundance of its substrates. Therefore, genetic mutations or decreases in its expression serve an important biological role in tumor development. In-depth studies and identification of additional substrates targeted by FBXW7 have suggested a signaling network regulated by FBXW7, including its tumor-inhibitory role. The present review focused on the role of FBXW7 in tumor suppression and its application in cancer therapy.

Killing the "BAD": Challenges for immunotherapy in pancreatic cancer

Cancer regression often fails after systemic immune activation, especially for solid tumors due to their local immunosuppressive microenvironments. Among these, the pancreatic cancer microenvironment is unique and an important reason for resistance to anti-cancer treatments that include immunotherapy. In this review, the three main "BAD" characteristics that create and maintain this immunosuppressive microenvironment are discussed for effector T cells: Barriers to overcome, Attraction problems, and their Disabilities. These inhibit both effector T-cell activation and infiltration, reducing immunotherapy effectiveness. Combination approaches for killing the "BAD" aim to normalize the tumor microenvironment and are recommended to enhance anti-cancer immune-system efficacy in pancreatic cancer.

Prior history of acute pancreatitis predicts poor survival in patients with resectable pancreatic ductal adenocarcinoma

BACKGROUND/OBJECTIVES

Mounting evidence has suggested that acute pancreatitis (AP) is a risk factor for pancreatic ductal adenocarcinoma (PDAC), but its role in survival in PDAC patients was rarely investigated. The objective was to investigate the association of a history of AP with survival among PDAC patients who underwent surgical resection.

METHODS

A retrospective cohort study comprising 632 patients who were diagnosed with resectable PDAC was conducted. Survival was evaluated by history of AP prior to a diagnosis of PDAC using Kaplan-Meier methods and log-rank tests. Multivariate analyses for mortality were estimated using the Cox proportional hazards model. Propensity score matching methods were used to balance the difference of clinical characteristics between patients with and without AP history.

RESULTS

The log-rank tests showed that patients with a history of AP had a worse overall survival than those without a history of AP (p = 0.006). The multivariable-adjusted hazard ratio (HR) for mortality comparing participants with AP to those without AP was 1.808 (95% CI: 1.241-2.632, p = 0.002). Patients with a recent history of AP (<2 years), rather than patients with a remote history of AP (≥2 years), were found to have significantly worse survival (p = 0.014) than those without a history of AP. After adjusted for PSM, history of AP remained an independent survival predictor of PDAC following surgical resection.

CONCLUSIONS

Our findings indicate that a history of AP, especially a recent history of AP, is associated with poor survival among patients with resectable pancreatic ductal adenocarcinoma.

Prognostic Value of the C-Reactive Protein/Lymphocyte Ratio in Pancreatic Cancer

BACKGROUND

Many inflammatory markers can be used for the prognostication of pancreatic cancer, but which combination of inflammatory factors may be the best remains unclear. This study focused on the potential feasibility of the newly discovered C-reactive protein (CRP)/lymphocyte ratio (CLR) as a prognostic biomarker for patients with pancreatic cancer.

METHODS

The study enrolled 997 patients with pancreatic cancer. Six combinations of inflammatory markers, namely, the neutrophil/lymphocyte ratio (NLR), the platelet/lymphocyte ratio (PLR), the CRP/albumin ratio (CAR), the neutrophil/albumin ratio (NAR), the platelet/albumin ratio (PAR), and CLR, were examined to determine which combination offers the highest accuracy for predicting poor survival by receiver operating characteristic curve analysis. The prognostic value of the CLR was analyzed by uni- and multivariate analyses.

RESULTS

The newly developed CLR was more accurate than the NLR, PLR, CAR, NAR, and PAR in predicting survival. The optimal cutoff value for the CLR was calculated to be 1.8 for survival. A CLR higher than 1.8 was associated with poor survival in both the univariate (hazard ratio [HR] 2.00; P < 0.001) and multivariate (HR 1.73; P < 0.001) analyses. In addition, a CLR higher than 1.8 was an independent risk factor for patients with stage 2 (HR 1.85; P = 0.001), stage 3 (HR 1.83; P = 0.001), or stage 4 (HR 1.70; P < 0.001) disease.

CONCLUSIONS

Pretreatment CLR can be considered a feasible biomarker for the prognostic prediction of pancreatic cancer. An elevated CLR was an independent risk factor for poor survival, with a cutoff value of 1.8.

A miR-146a-5p/TRAF6/NF-kB p65 axis regulates pancreatic cancer chemoresistance: functional validation and clinical significance

Background: Dysregulated microRNA (miRNA) expression in cancer can act as a key factor that modifies biological processes, including chemoresistance. Our study aimed to identify the miRNAs associated with gemcitabine (GEM) resistance in pancreatic ductal adenocarcinoma (PDAC) and to explore the potential mechanisms.

Methods: The miRNA microarray was used to identify miRNAs associated with GEM resistance. Quantitative real-time PCR was used to examine miR-146a-5p expression in paired PDAC and adjacent normal tissues. Bioinformatics analysis, luciferase reporter assays, and chromatin immunoprecipitation assays were used to confirm tumor necrosis factor receptor-associated factor 6 (TRAF6) as a direct target of miR-146a-5p and to explore the potential transcription factor binding and regulation by miR-146a-5p. In vitro and in vivo experiments were performed to investigate the mechanisms.

Results: MiR-146a-5p expression was significantly decreased in PDAC tissues compared with adjacent normal tissues, and miR-146a-5p expression correlated with prognosis in PDAC patients. Functional studies indicated that miR-146a-5p suppressed PDAC cell proliferation and sensitized PDAC cells to GEM chemotherapy by targeting the 3'-untranslated region (3′-UTR) of TRAF6. MiR-146a-5p was also observed to downregulate the TRAF6/NF-κB p65/P-gp axis, which regulates PDAC cell growth and chemoresistance.

Conclusions: Taken together, the results indicate that the miR-146a-5p/TRAF6/NF-κB p65 axis drives pancreatic chemoresistance by regulating P-gp, suggesting that miR-146a-5p may be utilized as a new therapeutic target and prognostic marker in PDAC patients.

PARP inhibitors in pancreatic cancer: molecular mechanisms and clinical applications

Pancreatic cancer is a highly lethal disease with a poor prognosis, and existing therapies offer only limited effectiveness. Mutation gene sequencing has shown several gene associations that may account for its carcinogenesis, revealing a promising research direction. Poly (ADP-ribose) polymerase (PARP) inhibitors target tumor cells with a homologous recombination repair (HRR) deficiency based on the concept of synthetic lethality. The most prominent target gene is BRCA, in which mutations were first identified in breast cancer and ovarian cancer. PARP inhibitors can trap the PARP-1 protein at a single-stranded break/DNA lesion and disrupt its catalytic cycle, ultimately leading to replication fork progression and consequent double-strand breaks. For tumor cells with BRCA mutations, HRR loss would result in cell death. Pancreatic cancer has also been reported to have a strong relationship with BRCA gene mutations, which indicates that pancreatic cancer patients may benefit from PARP inhibitors. Several clinical trials are being conducted and have begun to yield results. For example, the POLO (Pancreatic Cancer Olaparib Ongoing) trial has demonstrated that the median progression-free survival was observably longer in the olaparib group than in the placebo group. However, PARP inhibitor resistance has partially precluded their use in clinical applications, and the major mechanism underlying this resistance is the restoration of HRR. Therefore, determining how to use PARP inhibitors in more clinical applications and how to avoid adverse effects, as well as prognosis and treatment response biomarkers, require additional research. This review elaborates on future prospects for the application of PARP inhibitors in pancreatic cancer.

Prognostic Value and Clinical Predictors of Lymph Node Metastases in Pancreatic Neuroendocrine Tumors

OBJECTIVES

To investigate the correlation between lymph node metastasis (LNM) and various clinicopathological features of pancreatic neuroendocrine tumors (pNETs) and its impact on prognosis.

METHODS

We searched the Surveillance Epidemiology and End Results database (2004-2015) for patients with surgically treated pNETs. Factors correlated with LNMs were analyzed by logistic regression and by Cox analysis.

RESULTS

For tumors of 1 to 4 cm, age (P < 0.001, P = 0.014), grade (P < 0.001, P < 0.001), LNMs (P = 0.008, P < 0.001), and size (P = 0.038, P = 0.002) predicted overall survival (OS) and disease-specific survival (DSS). For tumor greater than 4 cm, age (P < 0.001, P = 0.001) and grade (P = 0.011, P = 0.048) were independent prognostic factors of OS and DSS. Lymph node metastasis modestly predicted DSS (P = 0.028) but not OS (P = 0.218).

CONCLUSIONS

In pNETs greater than 4 cm, LNM is not a predictor of OS and modestly predicts DSS, and lymphadenectomy may be unhelpful in these patients. For pNETs 1 to 4 cm, LNM predicts poor OS and DSS, which supports lymphadenectomy in these patients. Pancreas-sparing resection with only limited peripancreatic node sampling needs to be questioned.

TGFB1-induced autophagy affects the pattern of pancreatic cancer progression in distinct ways depending on SMAD4 status

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal malignancies. Given that macroautophagy/autophagy activation is prevalent in PDAC, the dual roles of autophagy could be involved in PDAC heterogeneity. In this work, we demonstrated that TGFB1 induced autophagic flux through SMAD4-dependent or SMAD4-independent pathways based on a distinct genetic context. In SMAD4-positive PDAC cells, TGFB1-induced autophagy promoted proliferation and inhibited migration by decreasing the nuclear translocation of SMAD4. Conversely, TGFB1-induced autophagy inhibited proliferation and promoted migration in SMAD4-negative cells through the regulation of MAPK/ERK activation. TGFB1 expression also positively correlated with LC3B expression in PDAC specimens. A high level of LC3B was associated with unfavorable overall survival (OS) and disease-free survival (DFS) in SMAD4-negative PDAC patients, although LC3B could not predict OS and DFS for the 110 PDAC patients. Thus, TGFB1-induced autophagy contributed to the different patterns of PDAC progression. This knowledge can aid in improving our understanding of the molecular classification of PDAC and might guide the development of therapeutic strategies for PDAC, especially for SMAD4-negative PDAC.Abbreviations: CDH1: cadherin 1; CDH2: cadherin 2; CI: combination index; CQ: chloroquine; DFS: disease-free survival; EMT: epithelial-to-mesenchymal transition; ERK: extracellular signal-regulated protein kinase; GFP: green fluorescent protein; IHC: immunohistochemistry; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAPK: mitogen-activated protein kinase; OS: overall survival; PBS: phosphate-buffered saline; PDAC: pancreatic ductal adenocarcinoma; RAP: rapamycin; RFP: red fluorescent protein; RT: room temperature; shRNA: short-hairpin RNA; SQSTM1: sequestosome 1; TCGA: The Cancer Genome Atlas; TEM: transmission electron microscopy; TGFB1: transforming growth factor beta 1; TMA: tissue microarray.

Haemoglobin, albumin, lymphocyte and platelet predicts postoperative survival in pancreatic cancer

BACKGROUND

Systemic inflammation and nutrition status play an important role in cancer metastasis. The combined index of hemoglobin, albumin, lymphocyte, and platelet (HALP), consisting of haemoglobin, albumin, lymphocytes, and platelets, is considered as a novel marker to reflect both systemic inflammation and nutrition status. However, no studies have investigated the relationship between HALP and survival of patients with pancreatic cancer following radical resection.

AIM

To evaluate the prognostic value of preoperative HALP in pancreatic cancer patients.

METHODS

The preoperative serum levels of hemoglobin, albumin, lymphocyte counts, and platelet counts were routinely detected in 582 pancreatic adenocarcinoma patients who underwent radical resection. The relationship between postoperative survival and the preoperative level of HALP was investigated.

RESULTS

Low levels of HALP were significantly associated with lymph node metastasis (P = 0.002), poor tumor differentiation (P = 0.032), high TNM stage (P = 0.008), female patients (P = 0.005) and tumor location in the head of the pancreas (P < 0.001). Low levels of HALP were associated with early recurrence [7.3 mo vs 16.3 mo, P < 0.001 for recurrence-free survival (RFS)] and short survival [11.5 mo vs 23.6 mo, P < 0.001 for overall survival (OS)] in patients with resected pancreatic adenocarcinoma. A low level of HALP was an independent risk factor for early recurrence and short survival irrespective of sex and tumor location.

CONCLUSION

Low levels of HALP may be a significant risk factor for RFS and OS in patients with resected pancreatic cancer.

Ferroptosis: Final destination for cancer?

Ferroptosis is a recently defined, non‐apoptotic, regulated cell death (RCD) process that comprises abnormal metabolism of cellular lipid oxides catalysed by iron ions or iron‐containing enzymes. In this process, a variety of inducers destroy the cell redox balance and produce a large number of lipid peroxidation products, eventually triggering cell death. However, in terms of morphology, biochemistry and genetics, ferroptosis is quite different from apoptosis, necrosis, autophagy‐dependent cell death and other RCD processes. A growing number of studies suggest that the relationship between ferroptosis and cancer is extremely complicated and that ferroptosis promises to be a novel approach for the cancer treatment. This article primarily focuses on the mechanism of ferroptosis and discusses the potential application of ferroptosis in cancer therapy.

Lewis antigen‑negative pancreatic cancer: An aggressive subgroup

Carbohydrate antigen 19‑9 (CA19‑9) is the most important biomarker for pancreatic cancer. Approximately 5‑10% of individuals are Lewis antigen negative with scarce secretion of CA19‑9 and fucosylation deficiency. However, the characteristics of Lewis‑negative pancreatic cancer are unidentified. Clinicopathological characteristics of 853 patients with pancreatic cancer were examined. Pancreatic cancer cell lines were sequenced for Lewis status. Morphological and molecular features of pancreatic cancer cells were compared. Orthotopic animal modes were established. Lewis‑negative patients had poorer outcome (P<0.001), higher metastatic rate (P=0.004), lower CA19‑9 expression (P<0.001) and higher MUC16 expression (P<0.001) than Lewis‑positive patients. Lewis‑negative cells (CaPan‑1, MiaPaCa‑2 and Panc‑1) showed a shuttle shape with scarce pseudopods. Overall, Lewis‑negative cells had higher proliferation rate, higher migration ability, lower fucosylation, lower CA19‑9 expression and higher MUC16 expression than Lewis‑positive cells (BxPC‑3, SU8686, SW1990). Lewis‑negative cell line MiaPaCa‑2 corresponded to larger orthotopic tumor than Lewis‑positive cells SU8686. Potential proteoglycans were identified in Lewis‑positive cancer, including EGFR, HSPG2, ADAM17, GPC1, ITGA2, CD40, IL6ST and GGT1. Therefore, Lewis‑negative pancreatic cancer is an aggressive subgroup with special clinical and molecular features.

Kras mutation correlating with circulating regulatory T cells predicts the prognosis of advanced pancreatic cancer patients

Purpose

Kras mutation and abnormal immune status are associated with pancreatic cancer development and progression. In this study, we evaluated the Kras mutation status in circulating tumor DNA and circulating T cell subsets in a cohort of advanced pancreatic cancer patients.

Methods

Samples were retrospectively obtained from a series of 210 pathological advanced pancreatic cancer patients between 2012 and 2014. The Kras mutation status was detected in cell‐free circulating tumor DNA (ctDNA) by ddPCR and circulating T cell subsets were analyzed by flow cytometry.

Results

Univariate analysis found that tumor node metastasis (TNM) stage, chemotherapy, circulating regulatory T cells, CA19‐9 levels, CA125 levels, and Kras^G12D and Kras^G12V mutations were significantly related to overall survival in advanced pancreatic cancer patients. Multivariate analysis identified that TNM stage (P = .03, HR:1.422), Tregs (P = .004, HR:1.522), CA19‐9 levels (P = .009, HR:1.488), Kras^G12D mutation (P = .044, HR:1.353), and Kras^G12V mutation (P = .001, HR:1.667) were independent prognostic markers. Furthermore, we found that Kras^G12V mutation in ctDNA was correlated with high circulating proportion of Tregs, and patients with both Kras^G12V mutation and high levels of Tregs were associated with extremely poor survival in advanced pancreatic cancer.

Conclusion

Kras^G12V mutation was associated with high circulating regulatory T cell levels, and both of them predicted worse prognosis in advanced pancreatic cancer patients.

Proposed Modification of the 8th Edition of the AJCC Staging System for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to improve the 8th edition (8th) of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The new 8th AJCC staging system for PDAC was released in October, 2016, and will be applied in clinical practice in 2018.

METHODS

Two large cohorts were included in this analysis. One consisted of 45,856 PDAC patients in the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014), and the other consisted of 3166 PDAC patients in the Fudan University Shanghai Cancer Center (FUSCC) database (2005-2015).

RESULTS

Using the 8th AJCC staging system, the median overall survival of the patients in the same stage varied widely among the different substages. We proposed a modified staging system based on median OS in which we maintained the T, N, and M definitions, but regrouped the substages. In the SEER cohort, the concordance index was higher for local disease with the modified staging system [0.637; 95% confidence interval (CI) 0.631-0.642] than with the 8th AJCC staging system (0.620, 95% CI 0.615-0.626). Similar findings were also observed in the FUSCC cohort. In addition, we verified the reliability of the modified staging system in an analysis of patients with different examined lymph node counts (≥15 or 1-14).

CONCLUSIONS

The modified 8th AJCC staging system for PDAC proposed in this study provides improvements and may be evaluated for potential adoption in the next edition.

The reciprocal regulation between host tissue and immune cells in pancreatic ductal adenocarcinoma: new insights and therapeutic implications

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death and is one of the most difficult-to-treat cancers. Surgical resection and adjuvant therapy have limited effects on the overall survival of PDAC patients. PDAC exhibits an immunosuppressive microenvironment, the immune response predicts survival, and activation of immune system has the potential to produce an efficacious PDAC therapy. However, chimeric antigen receptor T (CAR-T) cell immunotherapy and immune checkpoint blockade (ICB), which have produced unprecedented clinical benefits in a variety of different cancers, produce promising results in only some highly selected patients with PDAC. This lack of efficacy may be because existing immunotherapies mainly target the interactions between cancer cells and immune cells. However, PDAC is characterized by an abundant tumor stroma that includes a heterogeneous mixture of immune cells, fibroblasts, endothelial cells, neurons and some molecular events. Immune cells engage in extensive and dynamic crosstalk with stromal components in the tumor tissue in addition to tumor cells, which subsequently impacts tumor suppression or promotion to a large extent. Therefore, exploration of the interactions between the stroma and immune cells may offer new therapeutic opportunities for PDAC. In this review, we discuss how infiltrating immune cells influence PDAC development and explore the contributions of complex components to the immune landscape of tumor tissue. The roles of stromal constituents in immune modulation are emphasized. We also predict potential therapeutic strategies to target signals in the immune network in the abundant stromal microenvironment of PDAC.

Role of Damage DNA-Binding Protein 1 in Pancreatic Cancer Progression and Chemoresistance

Damaged DNA-binding protein 1 (DDB1) recruits nucleotide excision pathway proteins to form the UV-damaged DNA-binding protein complex and is required for DNA repair. DDB1 was reported to participate in apoptosis and chemoresistance regulation in several cancers. However, little is known about the function of DDB1 in pancreatic adenocarcinoma (PDAC). In this study, we reported that DDB1 functions as a tumor-promoting factor in PDAC by regulating cancer cell proliferation, epithelial-mesenchymal transition (EMT) and chemoresistance. Compared to normal pancreatic tissues, PDAC tissues had high expression levels of DDB1, and this high expression was positively correlated with poor prognosis. Furthermore, reductions in cell proliferation and EMT were observed in DDB1-deficient PDAC cell lines. Intriguingly, we also found that abrogation of DDB1 expression increased PDAC cell sensitivity to gemcitabine (GEM). Mechanistically, DDB1 knockdown was associated with an increase in deoxycytidine kinase expression in vivo and in vitro. In summary, our work demonstrated that DDB1 promotes PDAC progression and chemoresistance and may serve as a potential predictive marker and therapeutic target for PDAC treatment.

Simultaneous resection of the primary tumour and liver metastases after conversion chemotherapy versus standard therapy in pancreatic cancer with liver oligometastasis: protocol of a multicentre, prospective, randomised phase III control trial (CSPAC-1)

INTRODUCTION

Approximately 50% of pancreatic ductal adenocarcinoma (PDAC) patients are diagnosed with distant metastasis, especially liver metastasis. The current standard treatment for these stage IV patients is palliative chemotherapy. There is increasing agreement that synchronous PDAC and liver metastasis resection may benefit highly selected patients. Thus, the Chinese Study Group for Pancreatic Cancer (CSPAC)-1 trial is being launched to establish a strategy for selecting PDAC patients with liver oligometastases who may benefit from synchronous resection after conversion chemotherapy.

METHODS AND ANALYSIS

In this study, liver oligometastasis is defined as no more than three metastatic lesions irrespective of their distribution within the liver lobes. The trial contains two steps. In the first step, 1000 to 1200 needle biopsy-confirmed PDAC patients with liver oligometastases are eligible for inclusion. Candidates will receive first-line chemotherapy. The RECIST V.1.1 criteria combined with tumour markers will be applied to evaluate the tumour response to chemotherapy every two cycles. Pancreatic cancer and hepatic metastasis resectability will be identified by multidisciplinary teams. Approximately 300 patients who meet our criteria will enter the second step and be randomly assigned at a 1:1 ratio to simultaneous resection of the primary pancreatic cancer lesion and liver oligometastases if no extensive metastatic sites are found during surgery or standard chemotherapy. Postoperative chemotherapy is recommended, and regimen selection should be based on the preoperative chemotherapy regimen. The primary endpoint is real overall survival (from enrolment to death). This study was activated in July 2018 and is expected to complete accrual within 5 years.

ETHICS AND DISSEMINATION

This trial has been approved by the Clinical Research Ethics Committee of Fudan University Shanghai Cancer Centre. Written informed consent will be obtained from all participants. Serious adverse events will be reported. Trial results will be submitted for peer-reviewed publication.

TRIAL REGISTRATION NUMBER

NCT03398291; Pre-results.

Prognostic and diagnostic significance of galectins in pancreatic cancer: a systematic review and meta-analysis

Background

Galectins constitute a family of β-galactoside-binding proteins, which influence various hallmarks of pancreatic cancer, including cell proliferation, invasion and migration; immune escape; and angiogenesis. Although many studies have concentrated on the role of galectins in pancreatic cancer, the results remain controversial. Hence, we performed a comprehensive meta-analysis to clarify the precise diagnostic and prognostic value of galectins in pancreatic cancer.

Methods

PubMed/MEDLINE, EMBASE and Web of Science were used to search related published literature up to July 2019. Pooled hazard ratios (HRs), diagnostic accuracy variables and related 95% confidence intervals (CIs) were calculated using STATA 14.0 software.

Results

Eleven studies including 1227 participants met our inclusion criteria. High expression of galectin family was not correlated with overall survival (OS) in pancreatic cancer (HR, 1.19; 95% CI 0.67-2.11). According to subgroup analysis, high levels of galectin-1 were significantly correlated with worse OS in pancreatic cancer (HR, 4.77; 95% CI 2.47-9.21), while high levels of tandem-repeat galectins (galectin-4 or galectin-9) predicted both better OS (HR, 0.63; 95% CI 0.46-0.86) and disease-free survival (DFS) (HR, 0.63; 95% CI 0.48-0.83). The expression levels of galectin-3 did not directly correlate with prognosis (HR, 0.99; 95% CI 0.40-2.46). The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratios of galectin-3 were 0.64 (95% CI 0.41-0.82), 0.76 (95% CI 0.59-0.88), 2.70 (95% CI 1.21-6.1), and 0.47 (95% CI 0.23-0.98), respectively. The area under the curve (AUC) of galectin-3 was 0.77.

Conclusion

Taken together, our results suggest that high expression of galectin-1 and low levels of galectin-4 or galectin-9 are predictors of worse prognosis in pancreatic cancer patients. The expression of galectin-3 was not directly related to OS and other clinical characteristics. Although galectin-3 exhibited some diagnostic value in patients with pancreatic cancer in this meta-analysis, clinical application prospects remain to be validated. Further studies are warranted to confirm and strengthen these findings.

Validation and head-to-head comparison of four models for predicting malignancy of intraductal papillary mucinous neoplasm of the pancreas: A study based on endoscopic ultrasound findings

BACKGROUND

Several models are currently available for predicting the malignancy of pancreatic intraductal papillary mucinous neoplasm (IPMN), namely, the Pancreatic Surgery Consortium (PSC), the Japan Pancreas Society (JPS), the Johns Hopkins Hospital (JHH), and the Japan-Korea (JPN-KOR) models. However, a head-to-head comparison that shows which model is more accurate for this individualized prediction is lacking.

AIM

To perform a head-to-head comparison of the four models for predicting the malignancy of pancreatic IPMN.

METHODS

A total of 181 patients with IPMN who had undergone surgical resection were identified from a prospectively maintained database. The characteristics of IPMN in patients were recorded from endoscopic ultrasound imaging data and report archives. The performance of all four models was examined using Harrell’s concordance index (C-index), calibration plots, decision curve analyses, and diagnostic tests.

RESULTS

Of the 181 included patients, 94 were categorized as having benign disease, and the remaining 87 were categorized as having malignant disease. The C-indexes were 0.842 [95% confidence interval (CI): 0.782-0.901], 0.704 (95%CI: 0.626-0.782), 0.754 (95%CI: 0.684-0.824), and 0.650 (95%CI: 0.483-0.817) for the PSC, JPS, JHH, and JPN-KOR models, respectively. Calibration plots showed that the PSC model had the least pronounced departure from ideal predictions. Of the remaining three models, the JPS and JHH models underestimated the probability of malignancy, while the JPN-KOR model overestimated the malignant potential of branch duct-IPMN. Decision curve analysis revealed that the PSC model resulted in a better clinical net benefit than the three other models. Diagnostic tests also showed a higher accuracy (0.801) for the PSC model.

CONCLUSION

The PSC model exhibited the best performance characteristics. Therefore, the PSC model should be considered the best tool for the individualized prediction of malignancy in patients with pancreatic IPMN.

Tumor-infiltrating platelets predict postoperative recurrence and survival in resectable pancreatic neuroendocrine tumor

BACKGROUND

Platelets have been reported to participate in tumor cell growth, extravasation, epithelial–mesenchymal transition, metastasis, and drug resistance. However, the importance of platelets in pancreatic neuroendocrine tumor (pNET) lacks adequate literature support. The predictive value of tumor-infiltrating platelets (TIPs) in pNET remains unclear.

AIM

To investigate the relationship between TIPs and the prognosis of patients with pNET following radical resection.

METHODS

In total, 113 patients who had undergone radical surgical resection with a pathologic diagnosis of pNET were enrolled in this study. Immunohistochemical analysis of cluster of differentiation 42b (CD42b) expression in the tumor specimens was performed to determine the presence of TIPs. Univariate and multivariate analyses were used to analyze the prognostic value of TIPs.

RESULTS

TIPs were observed in intratumoral areas in 54 patients. Neither basic characteristics nor preoperative platelet-associated indicators showed a significant relationship with the presence of TIPs (all P > 0.05). Patients with positive intratumoral CD42b expression had worse overall survival (P = 0.005) and recurrence-free survival (P < 0.001) than those with negative intratumoral CD42b expression. Multivariate analysis demonstrated that TIPs were independent prognostic factors for overall survival (P = 0.049) and recurrence-free survival (P = 0.003). Nevertheless, platelet count, mean platelet volume, and platelet-to-lymphocyte ratio were not associated with postoperative survival or recurrence in pNET patients (all P > 0.05).

CONCLUSION

TIPs are a useful prognostic biomarker for patients with resectable pNET, and their detection represents a promising tool for pNET treatment strategy decisions.