OBJECTIVE: The aim of this study was to determine the role of site-specific metastatic patterns over time and assess factors associated with extended survival in metastatic PDAC. Half of all patients with pancreatic ductal adenocarcinoma (PDAC) present with metastatic disease. The site of metastasis plays a crucial role in clinical decision making due to its prognostic value.
METHODS: We examined 56,757 stage-IV PDAC patients from the National Cancer Database (2016-2019), categorizing them by metastatic site: multiple, liver, lung, brain, bone, carcinomatosis, or other. The site-specific prognostic value was assessed using log-rank tests while time-varying effects were assessed by Aalen\'s linear hazards model. Factors associated with extended survival (>3years) were assessed with logistic regression.
RESULTS: Median overall survival (mOS) in patients with distant lymph node-only metastases (9.0 months) and lung-only metastases (8.1 months) was significantly longer than in patients with liver-only metastases (4.6 months, p < 0.001). However, after six months, the metastatic site lost prognostic value. Logistic regression identified extended survivors (3.6 %) as more likely to be younger, Hispanic, privately insured, Charlson-index <2, having received chemotherapy, or having undergone primary or distant site surgery (all p < 0.001).
CONCLUSIONS: While synchronous liver metastases are associated with worse outcomes than lung-only and lymph node-only metastases, this predictive value is diminished after six months. Therefore, treatment decisions beyond this time should not primarily depend on the metastatic site. Extended survival is possible in a small subset of patients with favorable tumor biology and good conditional status, who are more likely to undergo aggressive therapies.

Pancreatic cancer, predominantly pancreatic ductal adenocarcinoma (PDAC), remains a highly lethal malignancy with limited therapeutic options and a dismal prognosis. By targeting the underlying molecular abnormalities responsible for PDAC development and progression, gene therapy offers a promising strategy to overcome the challenges posed by conventional radiotherapy and chemotherapy. This study sought to explore the therapeutic potential of small activating RNAs (saRNAs) specifically targeting the CCAAT/enhancer-binding protein alpha (CEBPA) gene in PDAC. To overcome the challenges associated with saRNA delivery, tetrahedral framework nucleic acids (tFNAs) were rationally engineered as nanocarriers. These tFNAs were further functionalized with a truncated transferrin receptor aptamer (tTR14) to enhance targeting specificity for PDAC cells. The constructed tFNA-based saRNA formulation demonstrated exceptional stability, efficient saRNA release ability, substantial cellular uptake, biocompatibility, and nontoxicity. In vitro experiments revealed successful intracellular delivery of CEBPA-saRNA utilizing tTR14-decorated tFNA nanocarriers, resulting in significant activation of tumor suppressor genes, namely, CEBPA and its downstream effector P21, leading to notable inhibition of PDAC cell proliferation. Moreover, in a mouse model of PDAC, the tTR14-decorated tFNA-mediated delivery of CEBPA-saRNA effectively upregulated the expression of the CEBPA and P21 genes, consequently suppressing tumor growth. These compelling findings highlight the potential utility of saRNA delivered via a designed tFNA nanocarrier to induce the activation of tumor suppressor genes as an innovative therapeutic approach for PDAC.

DNA mismatch repair gene MutL homolog-1 (MLH1) has divergent effects in many cancers, however, its impact on the metastasis of pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this study, MLH1 stably overexpressed (OE) and knockdowned (KD) sub-lines were established. Wound-healing and Transwell assays were used to evaluate cell migration/invasion. In vivo metastasis was investigated in orthotopic implantation models (SCID mice). RT-qPCR and western blotting were adopted to show gene/protein expression. MLH1 down-stream genes were screened by transcriptome sequencing. Tissue microarray-based immunohistochemistry was applied to determine protein expression in human specimens. In successfully generated sub-lines, OE cells presented weaker migration/invasion abilities, compared with controls, while in KD cells these abilities were significantly stronger. The metastasis-inhibitory effect of MLH1 was also observed in mice. Mechanistically, G-protein coupled receptor C5C (GPRC5C) was a key down-stream gene of MLH1 in PDAC cells. Subsequently, transient GPRC5C silencing effectively inhibited cell migration/invasion, and remarkably reversed the pro-invasive effect of MLH1 knockdown in KD cells. In animal models and human PDAC tissues, tumoral GPRC5C expression, negatively associated with MLH1 expressions, was positively correlated with histological grade, vessel invasion, and poor cancer-specific survival. In conclusion, MLH1 inhibits the metastatic potential of PDAC via down-regulation of GPRC5C.

The peripheral nervous system is a key regulator of cancer progression. In pancreatic ductal adenocarcinoma (PDAC), the sympathetic branch of the autonomic nervous system inhibits cancer development. This inhibition is associated with extensive sympathetic nerve sprouting in early pancreatic cancer precursor lesions. However, the underlying mechanisms behind this process remain unclear. This study aimed to investigate the roles of pancreatic Schwann cells in the structural plasticity of sympathetic neurons. We examined the changes in the number and distribution of Schwann cells in a transgenic mouse model of PDAC and in a model of metaplastic pancreatic lesions induced by chronic inflammation. Schwann cells proliferated and expanded simultaneously with new sympathetic nerve sprouts in metaplastic/neoplastic pancreatic lesions. Sparse genetic labeling showed that individual Schwann cells in these lesions had a more elongated and branched structure than those under physiological conditions. Schwann cells overexpressed neurotrophic factors, including glial cell-derived neurotrophic factor (GDNF). Sympathetic neurons upregulated the GDNF receptors and exhibited enhanced neurite growth in response to GDNF in vitro. Selective genetic deletion of Gdnf in Schwann cells completely blocked sympathetic nerve sprouting in metaplastic pancreatic lesions in vivo. This study demonstrated that pancreatic Schwann cells underwent adaptive reprogramming during early cancer development, supporting a protective antitumor neuronal response. These finding could help to develop new strategies to modulate cancer associated neural plasticity.

UNASSIGNED: Distal pancreatectomy (DP) with lymph node (LN) dissection is the standard procedure for pancreatic ductal adenocarcinoma of the tail (Pt-PDAC). However, the optimal surgery including extent of LN dissection is still being debated. The present study investigated the incidence and prognostic impact of LN metastasis on patients suffering from Pt-PDAC.
UNASSIGNED: This multicenter, retrospective study involved 163 patients who underwent DP for resectable Pt-PDAC at 12 institutions between 2013 and 2017. The frequency of LN metastasis and the effect of LN dissection on Pt-PDAC prognosis were investigated.
UNASSIGNED: There were high incidences of metastases to the LNs along the splenic artery in the patients with Pt-PDAC (39%). The rate of metastases in the LNs along the common hepatic, left gastric, and celiac arteries were low, and the therapeutic index for these LNs was zero. In pancreatic tail cancer located more distally, there were no metastases to the LNs along the common hepatic artery. Multivariate analysis revealed that tumor size was the only independent factor related to recurrence-free survival (HR = 2.01, 95% CI = 1.33-3.05, p = 0.001). The level of pancreas division and LN dissection along the common hepatic artery did not affect the site of tumor recurrence or recurrence-free survival.
UNASSIGNED: LN dissection along the hepatic artery for Pt-PDAC has little significance. Distal pancreatic transection may be acceptable in terms of oncological safety, but further examination of short-term outcomes and preservation of pancreatic function is required.

BACKGROUND: Patients with pancreatic ductal adenocarcinoma (PDAC) display an altered oral, gastrointestinal, and intra-pancreatic microbiome compared to healthy individuals. However, knowledge regarding the bile microbiome and its potential impact on progression-free survival in PDACs remains limited.
METHODS: Patients with PDAC (n = 45), including 20 matched pairs before and after surgery, and benign controls (n = 16) were included prospectively. The characteristics of the microbiomes of the total 81 bile were revealed by 16  S-rRNA gene sequencing. PDAC patients were divided into distinct groups based on tumor marker levels, disease staging, before and after surgery, as well as progression free survival (PFS) for further analysis. Disease diagnostic model was formulated utilizing the random forest algorithm.
RESULTS: PDAC patients harbor a unique and diverse bile microbiome (PCoA, weighted Unifrac, p = 0.038), and the increasing microbial diversity is correlated with dysbiosis according to key microbes and microbial functions. Aliihoeflea emerged as the genus displaying the most significant alteration among two groups (p < 0.01). Significant differences were found in beta diversity of the bile microbiome between long-term PFS and short-term PFS groups (PCoA, weighted Unifrac, p = 0.005). Bacillota and Actinomycetota were identified as altered phylum between two groups associated with progression-free survival in all PDAC patients. Additionally, we identified three biomarkers as the most suitable set for the random forest model, which indicated a significantly elevated likelihood of disease occurrence in the PDAC group (p < 0.0001). The area under the receiver operating characteristic (ROC) curve reached 80.8% with a 95% confidence interval ranging from 55.0 to 100%. Due to the scarcity of bile samples, we were unable to conduct further external verification.
CONCLUSIONS: PDAC is characterized by an altered microbiome of bile ducts. Biliary dysbiosis is linked with progression-free survival in all PDACs. This study revealed the alteration of the bile microbiome in PDACs and successfully developed a diagnostic model for PDAC.

Objective To construct a risk prediction model by integrating the molecular subtypes of pancreatic ductal adenocarcinoma (PDAC) and immune-related genes.Methods With GSE71729 data set (n=145) as the training set,the differentially expressed genes and differential immune-related genes between the squamous and non-squamous subtypes of PDAC were integrated to construct a regulatory network,on the basis of which five immune marker genes regulating the squamous subtype were screened out.An integrated immune score (IIS) model was constructed based on patient survival information and immune marker genes to predict the clinical prognosis of PDAC patients,and its predictive performance was tested with 5 validation sets (n=758).Results PDAC patients were assigned into high risk and low risk groups according to the IIS.In both training and validation sets,the overall survival of patients in the high risk group was shorter than that in the low risk group (both P<0.001).The multivariable Cox regression showed that IIS was an independent prognostic factor for PDAC (HR=2.16,95%CI=1.50-3.10,P<0.001).Conclusion IIS can be used for risk stratification of PDAC patients and may become a potential prognostic marker for PDAC.
目的 构建整合胰腺导管腺癌(PDAC)分子亚型和免疫相关基因的风险评估模型。方法 以GSE71729数据集(n=145)为训练集,整合PDAC鳞状和非鳞状亚型之间差异表达基因和差异免疫相关基因构建调控网络,筛选发挥主调控鳞状亚型的5个免疫标志基因。基于患者生存信息和免疫标志基因构建整合免疫评分(IIS)模型来预测PDAC患者的临床预后,并在5个验证集(n=758)中检验其预测效能。结果 根据IIS将PDAC患者分为高危组和低危组。在训练集和验证集中,高危组患者的总体生存期均短于低危组(P均<0.001)。多变量Cox回归分析显示IIS是PDAC的独立预后因子(HR=2.16,95%CI=1.50~3.10,P<0.001)。结论 IIS可用于PDAC患者的危险分层,并可能成为PDAC潜在的预后标志物。.

The NK cell is an important component of the tumor microenvironment of pancreatic ductal adenocarcinoma (PDAC), also plays a significant role in PDAC development. This study aimed to explore the relationship between NK cell marker genes and prognosis, immune response of PDAC patients. By scRNA-seq data, we found the proportion of NK cells were significantly downregulated in PDAC and 373 NK cell marker genes were screened out. By TCGA database, we enrolled 7 NK cell marker genes to construct the signature for predicting prognosis in PDAC patients. Cox analysis identified the signature as an independent factor for pancreatic cancer. Subsequently, the predictive power of signature was validated by 6 GEO datasets and had an excellent evaluation. Our analysis of relationship between the signature and patients\' immune status revealed that the signature has a strong correlation with immunocyte infiltration, inflammatory reaction, immune checkpoint inhibitors (ICIs) response. The NK cell marker genes are closely related to the prognosis and immune capacity of PDAC patients, and they have potential value as a therapeutic target.

UNASSIGNED: To explore the relationship between baseline clinical characteristics and hematological parameters of patients undergoing radical resection for pancreatic ductal adenocarcinoma (PDAC) and their prognosis, and to provide references for stratifying the patients\' clinical risks.
UNASSIGNED: We retrospectively collected clinical data from 445 patients who underwent radical surgical treatment for PDAC at West China Hospital, Sichuan University between January 2010 and February 2019. Then, we conducted retrospective clinical analysis with the collected data. Data on patients\' basic clinical characteristics, routine blood test results, and tumor indicators were collected to explore their effects on the postoperative overall survival (OS) of PDAC patients. Cox proportional hazards regression was used to identify factors affecting OS. Statistical analysis was performed using the SPSS 23.0 software package.
UNASSIGNED: The postoperative median overall survival (mOS) was 17.0 months (95% CI: 15.0-19.0). The 1, 2, 3, 4, and 5-year survival rates of the patients included in the study were 60.6%, 33.4%, 19.1%, 12.7%, and 9.6%, respectively. The multivariate Cox proportional hazards model analysis demonstrated that a number of factors independently affect postoperative survival in PDAC patients. These factors include tumor location (hazards ratio [HR]=1.574, 95% CI: 1.233-2.011), degree of tumor cell differentiation (HR=0.687, 95% CI: 0.542-0.870), presence of neural invasion (HR=0.686, 95% CI: 0.538-0.876), TNM staging (HR=1.572, 95% CI: 1.252-1.974), postoperative adjuvant therapy (HR=1.799, 95% CI: 1.390-2.328), preoperative drinking history (HR=0.744, 95% CI: 0.588-0.943), and high serum CA199 levels prior to the surgery (HR=0.742, 95% CI: 0.563-0.977).
UNASSIGNED: In PDAC patients, having tumors located in the head of the pancreas, moderate and high degrees of differentiated, being free from local neurovascular invasion, being in TNM stage Ⅰ, undergoing postoperative adjuvant therapy, no history of alcohol consumption prior to the surgery, and preoperative serum CA199 being less than or equal to 37 U/mL are significantly associated with a better prognosis.

UNASSIGNED: Pancreatic ductal adenocarcinoma (PDAC) is in urgent need of a second-line or later-line treatment strategy. We aimed to analyze the efficacy and safety of additional anlotinib, specifically anlotinib in combination with immunotherapy, in patients with PDAC who have failed first-line therapy.
UNASSIGNED: Patients with pathological diagnosis of PDAC were additionally treated with anlotinib, and some patients were treated with anti-PD-1 agents at the same time, which could be retrospectively analyzed. The efficacy and safety of additional anlotinib were evaluated.
UNASSIGNED: A total of 23 patients were included. In patients treated with additional anlotinib, the overall median progression-free survival (PFS) was 1.8 months and the median overall survival (OS) was 6.3 months, regardless of anti-PD-1 agents. Among patients receiving additional anlotinib in combination with anti-PD-1 agents, median PFS and OS were 1.8 and 6.5 months, respectively. Adverse events (AEs) were observed in 16 patients (69.6%). In patients treated with additional anlotinib, the majority of AEs were grade 1-3. Univariate analysis revealed that patients with baseline red blood cell distribution width (RDW) <14% treated with additional anlotinib plus anti-PD-1 agents had significantly longer OS than patients with baseline RDW ≥14% (p = 0.025). Patients with additional anlotinib plus anti-PD-1 agents as second-line therapy had a longer OS than those treated as later-line therapy (p = 0.012). Multivariate analysis showed that baseline RDW was the only independent risk factor for OS (p = 0.042).
UNASSIGNED: The combination of anlotinib and immunotherapy represents an effective add-on therapy with tolerable AEs as second- or later-line therapy in patients with PDAC, particularly in patients with baseline RDW <14%.