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Background/Objectives : The usefulness of dual-energy computed tomography (DECT) for low absorption in the parenchymal phase and contrast effects in the delayed phase for pancreatic cancer is not clear. Therefore, the diagnostic capability of low-KeV images obtained using DECT for pancreatic cancer in the pancreatic parenchymal and delayed phases was evaluated quantitatively and qualitatively. Methods : Twenty-five patients with pancreatic cancer who underwent contrast-enhanced DECT were included. A total of 50 and 70 KeV CT images, classified as low-keV and conventional CT-equivalent images, were produced, respectively. The tumor-to-pancreas contrast (Hounsfield units [HU]) in the pancreatic parenchymal and delayed phases was calculated by subtracting the CT value of the pancreatic tumor from that of normal parenchyma. Results : The median tumor-to-pancreas contrast on 50 KeV CT in the pancreatic parenchymal phase (133 HU) was higher than that on conventional CT (68 HU) ( p < 0.001). The median tumor-to-pancreas contrast in the delayed phase was -28 HU for 50 KeV CT and -9 HU for conventional CT ( p = 0.545). For tumors < 20 mm, the tumor-to-pancreas contrast of 50 KeV CT (-39 HU) had a significantly clearer contrast effect than that of conventional CT (-16.5 HU), even in the delayed phase ( p = 0.034). Conclusions : These 50 KeV CT images may clarify the low-absorption areas of pancreatic cancer in the pancreatic parenchymal phase. A good contrast effect was observed in small pancreatic cancers on 50 KeV delayed-phase images, suggesting that DECT is useful for the visualization of early pancreatic cancer with a small tumor diameter.

Pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate; therefore, the development of effective treatments is a priority. The stimulator of interferon genes (STING) pathway enhances tumor immunity by inducing the production of type 1 interferon (IFN) and proinflammatory cytokines and chemokines and promoting the infiltration of cytotoxic T cells. To assess the function of STING on pancreatic tumorigenesis, Ptf1a ER-Cre/+ LSL-Kras G12D/+ p53 loxP/loxP mice (KPC mice) and Ptf1a ER-Cre/+ LSL-Kras G12D/+ p53 loxP/loxP /STING -/- mice (KPCS mice) were generated. However, STING deletion did not affect pancreatic tumorigenesis in mice. Because STING is expressed not only in immune cells but also in cancer-associated fibroblasts (CAFs), we evaluated the STING function in PDAC CAFs. A mouse STING agonist 5,6-Dimethyl-9-oxo-9H-xanthene-4-acetic acid (DMXAA) was administered to KPC mice and CAFs from KPC mice and the resulting immune response was evaluated. DMXAA activated STING in PDAC CAFs in KPC mice, promoting cytotoxic T cell infiltration by secreting proinflammatory cytokines and enhancing tumor immunity. We next generated STING-deficient PDAC cells and subcutaneous tumors in which STING was expressed only in CAFs by performing bone marrow transplantation and assessed the antitumor effect of STING-activated CAFs. The administration of DMXAA to subcutaneous tumors expressing STING only in CAFs sustained the antitumor effect of DMXAA. About half of human PDACs lacked STING expression in the cancer stroma, suggesting that STING activation in PDAC CAFs exerts an antitumor effect, and STING agonists can be more effective in tumors with high than in those with low STING expression in the stroma., (© 2024. The Author(s).)

According to cancer genome sequences, more than 90% of cases of pancreatic ductal adenocarcinoma (PDAC) harbor active KRAS mutations. Digital PCR (dPCR) enables accurate detection and quantification of rare mutations. We assessed the dynamics of circulating tumor DNA (ct-DNA) in patients with advanced PDAC undergoing chemotherapy using dPCR. KRAS G12/13 mutation was assayed by dPCR in 47 paired tissue- and ct-DNA samples. The 21 patients were subjected to quantitative ct-DNA monitoring at 4 to 8-week intervals during chemotherapy. KRAS mutation was detected in 45 of those 47 patients using tissue DNA. In the KRAS mutation-negative cases, next-generation sequencing revealed KRAS Q61K and NRAS Q61R mutations. KRAS mutation was detected in 23/45 cases using ct-DNA (liver or lung metastasis, 18/19; mutation allele frequency [MAF], 0.1%-31.7%; peritoneal metastasis, 3/9 [0.1%], locally advanced, 2/17 [0.1%-0.2%]). In the ct-DNA monitoring, the MAF value changed in concordance with the disease state. In the 6 locally advanced cases, KRAS mutation appeared concurrently with liver metastasis. Among the 6 cases with liver metastasis, KRAS mutation disappeared during the duration of stable disease or a partial response, and reappeared at the time of progressive disease. The median progression-free survival was longer in cases in which KRAS mutation disappeared after an initial course of chemotherapy than in those in which it was continuously detected (248.5 vs 50 days, P < .001). Therefore, ct-DNA monitoring enables continuous assessment of disease state and could have prognostic utility during chemotherapy., (© 2019 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background & Aims: E-cadherin (Cdh1) is a key molecule for adherence required for maintenance of structural homeostasis. Loss of E-cadherin leads to poor prognosis and the development of resistance to chemotherapy in pancreatic cancer. Here, we evaluated the physiological and pathologic roles of E-cadherin in the pancreas., Methods: We crossbred Ptf1a-Cre mice with Cdh1 f /f mice to examine the physiological roles of E-cadherin in the pancreas. In addition, we crossbred these mice with LSL-Kras G12D/+ mice (PKC) to investigate the pathologic roles of E-cadherin. We also generated a tamoxifen-inducible system (Ptf1a-Cre ERT model). Organoids derived from these models using lentiviral transduction were analyzed for immunohistochemical features. Established cell lines from these organoids were analyzed for migratory and invasive activities as well as gene expression by complementary DNA microarray analyses., Results: None of the Ptf1a-Cre mice crossbred with Cdh1 f/f mice survived for more than 28 days. We observed aberrant epithelial tubules that resembled the structure of acinar-to-ductal metaplasia after postnatal day 6, showing features of pancreatitis. All of the PKC mice died within 10 days. We observed tumorigenicity with increasing stroma-like aggressive tumors. Ptf1a-Cre ERT models showed that deletion of E-cadherin led to earlier pancreatic intraepithelial neoplasm formation. Cells established from PKC organoids had greater migratory and invasive activities, and these allograft tumors showed a poorly differentiated phenotype. Gene expression analysis indicated that Hdac1 was up-regulated in PKC cell lines and a histone deacetylase 1 inhibitor suppressed PKC cell proliferation., Conclusions: Under physiological conditions, E-cadherin is important for maintaining the tissue homeostasis of the pancreas. Under pathologic conditions with mutational Kras activation, E-cadherin plays an important role in tumor formation via the acquisition of tumorigenic activity., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Endoscopic duodenal stenting has recently been proposed as a substitute for surgical gastrojejunostomy for the treatment of gastric outlet obstruction. We aimed to evaluate the efficacy and safety of duodenal stenting followed by systemic chemotherapy for patients with advanced pancreatic cancer with gastric outlet obstruction., Methods: This was a single-center, retrospective cohort study, conducted at an academic medical center, of 71 patients with advanced pancreatic cancer and gastric outlet obstruction (mean age: 67.6 years; range: 31-92 years) who underwent duodenal stenting with or without subsequent chemotherapy. Overall survival, duration of oral intake of foods, the rate of introduction of chemotherapy, progression-free survival, and adverse events were evaluated., Results: Stent placement was technically successful in 69 (97%) patients. Thirty-six (51%) patients were treated with chemotherapy: 17 with gemcitabine alone, 15 with S-1 alone, 3 with FOLFIRINOX, and 1 with paclitaxel. Median progression-free survival and overall survival after chemotherapy were 2.6 months (95% confidence interval: 1.3-3.9 months) and 4.7 months (95% confidence interval: 2.6-6.8 months), respectively. Cases of grade 3 anemia were frequently observed during chemotherapies following duodenal stenting (32%). Tumor stage, performance status, neutrophil-to-lymphocyte ratio, and introduction of chemotherapy were independent prognostic factors for survival (hazard ratios of 3.73, 2.21, 2.69, and 1.85 with p-values of <0.001, 0.010, <0.001, and 0.045, respectively)., Conclusions: The findings of this study suggest that endoscopic duodenal stenting is an advantageous treatment in advanced pancreatic cancer patients with gastric outlet obstruction regarding its safety and smooth conduction of subsequent chemotherapies., (Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Objective: In this subanalysis of a phase III trial using three categorized doses of S-1, the influence of the actual doses on safety and efficacy was evaluated., Methods: We compared the efficacy and safety of the S-1 or gemcitabine plus S-1 combination (GS) arm between the top 10% group and the bottom 10% group according to the initial doses of S-1: ≥77.6 versus ≤65.9 mg/m2/day (n = 28 vs. 28) in the S-1 arm, and ≥65.1 versus ≤53.8 mg/m2/day (n = 27 vs. 28) in the GS arm., Results: Overall and progression-free survival were not significantly different between these two groups: hazard ratios of 0.818 and 0.761 with p values of 0.498 and 0.330 in the S-1 arm, and hazard ratios of 0.836 and 0.759 with p values of 0.557 and 0.323 in the GS arm, respectively. Incidences of grade 3-4 hematological toxicities were significantly higher in the top 10% group than in the bottom 10% group: 42.9 versus 14.3 and 85.2 versus 57.1%, with p values of 0.037 and 0.037 in the S-1 and the GS combination arm, respectively., Conclusions: Higher actual doses of S-1 were associated with a higher incidence of hematological toxicity even in the same dose setting., (© 2016 S. Karger AG, Basel.)

Objectives: Seven-signal proteomic approach has recently been developed as a new proteomic profile measured by matrix-assisted laser desorption/ionization mass spectrometry. The aim of this study was to evaluate prognostic significance of this proteomic value in patients with pancreatic adenocarcinoma., Methods: Blood samples from the patients with pancreatic adenocarcinoma were prospectively collected before treatments including surgical resection and systemic chemotherapies. The seven-signal proteomic profiles of the samples were measured, and the prognostic significance of the proteomic value was evaluated through comparison with other existing prognostic markers., Results: Cut-off value of the proteomic profiles at 52 stratified overall prognosis of the patients (6.5 months vs. 10.9 months with the values ≥52 vs. <52, p = 0.020). In subgroup analyses of inoperable cases with carcinoembryonic antigen level of <5 ng/ml or performance status of 0-1, the proteomic value at 52 stratified their prognosis (p = 0.002 and p = 0.006, respectively)., Conclusions: The new seven-signal proteomics showed useful prognostic significance for patients with pancreatic adenocarcinoma. Further studies with a large sample size would be required to evaluate whether this proteomic approach possibly complements the existing parameters, such as carcinoembryonic antigen and performance status., (Copyright © 2015 IAP and EPC. Published by Elsevier B.V. All rights reserved.)