Concordance of ctDNA and tissue genomic profiling in advanced biliary tract cancer.

BACKGROUND & AIMS: Recent advances in molecular profiling enable the identification of potential therapeutic targets for biliary tract cancer (BTC). However, in patients with BTC, molecular profiling is hindered by challenges in obtaining adequate tissue samples. Circulating tumor DNA (ctDNA) may offer an alternative to tissue-based analysis. Here we aimed to assess the concordance between ctDNA and tissue genomic profiling in a large cohort of Asian patients with advanced BTC, and to evaluate the feasibility of liquid biopsy in BTC treatment. METHODS: This study included patients with systemic treatment-naive advanced BTC, treated at CHA Bundang Medical Center between January 2019 and December 2022. We enrolled patients with available baseline tissue-based next-generation sequencing (NGS), and sufficient plasma samples for ctDNA analysis (AlphaLiquid®100 from IMBdx). RESULTS: Among 102 enrolled patients, 49.0% had intrahepatic cholangiocarcinoma, 26.5% extrahepatic cholangiocarcinoma, and 24.5% gallbladder cancer. The concordance between intra-patient ctDNA and tumor tissue mutations revealed a sensitivity of 84.8%, and positive predictive value of 79.4%. ctDNA revealed targetable alterations in 34.3% of patients-including FGFR2 fusion, IDH1 mutation, microsatellite instability (MSI)-high, ERBB2 amplification, PIK3CA mutations, BRCA1/2 mutations, and MET amplification. Notably, a novel FGFR2-TNS1 fusion was identified in ctDNA, which was not targeted in the tissue NGS panel. A high maximum somatic variant allele frequency in ctDNA was associated with poor prognosis after gemcitabine/cisplatin-based chemotherapy, in terms of both overall survival (p = 6.9 × 10-6) and progression-free survival (p = 3.8 × 10-7). CONCLUSIONS: Among patients with advanced BTC, ctDNA-based genotyping showed acceptable concordance with tissue genomic profiling. Liquid biopsy using ctDNA could be a valuable complement to tissue-based genomic analysis in BTC. IMPACT AND IMPLICATIONS: Our study is the first large-scale investigation of the clinical utility of liquid biopsy, focusing on ctDNA, as an alternative to conventional tumor tissue analysis, among Asian patients with advanced BTC. The results demonstrated acceptable concordance between analysis of ctDNA versus tissue for identifying therapeutic targets and potentially actionable genetic alterations. This indicates that ctDNA analysis can provide critical insights regarding advanced BTC treatment, particularly in cases where it is challenging to obtain or analyze tumor tissue.

Surface Doping and Dual Nature of the Band Gap in Excitonic Insulator Ta2NiSe5.

Excitons in semiconductors and molecules are widely utilized in photovoltaics and optoelectronics, and high-temperature coherent quantum states of excitons can be realized in artificial electron-hole bilayers and an exotic material of an excitonic insulator (EI). Here, we investigate the band gap evolution of a putative high-temperature EI Ta2NiSe5 upon surface doing by alkali adsorbates with angle-resolved photoemission and density functional theory (DFT) calculations. The conduction band of Ta2NiSe5 is filled by the charge transfer from alkali adsorbates, and the band gap decreases drastically upon the increase of metallic electron density. Our DFT calculation, however, reveals that there exist both structural and excitonic contributions to the band gap tuned. While electron doping reduces the band gap substantially, it alone is not enough to close the band gap. In contrast, the structural distortion induced by the alkali adsorbate plays a critical role in the gap closure. This work indicates a combined electronic and structural nature for the EI phase of the present system and the complexity of surface doping beyond charge transfer.

High-temperature concomitant metal-insulator and spin-reorientation transitions in a compressed nodal-line ferrimagnet Mn3Si2Te6.

Symmetry-protected band degeneracy, coupled with a magnetic order, is the key to realizing novel magnetoelectric phenomena in topological magnets. While the spin-polarized nodal states have been identified to introduce extremely-sensitive electronic responses to the magnetic states, their possible role in determining magnetic ground states has remained elusive. Here, taking external pressure as a control knob, we show that a metal-insulator transition, a spin-reorientation transition, and a structural modification occur concomitantly when the nodal-line state crosses the Fermi level in a ferrimagnetic semiconductor Mn3Si2Te6. These unique pressure-driven magnetic and electronic transitions, associated with the dome-shaped Tc variation up to nearly room temperature, originate from the interplay between the spin-orbit coupling of the nodal-line state and magnetic frustration of localized spins. Our findings highlight that the nodal-line states, isolated from other trivial states, can facilitate strongly tunable magnetic properties in topological magnets.

Anti-fibrotic and anti-stricture effects of biodegradable biliary stents braided with dexamethasone-impregnated sheath/core structured monofilaments.

Endoscopic biliary stent insertion has been widely used for the treatment of benign biliary stricture (BBS). Thus, the development of stent materials in the perspectives of structure, mechanical properties, and biocompatibility has been also studied. However, conventional metal and plastic stents have several disadvantages, such as repeated procedures to remove or exchange them, dislodgment, restenosis, biocompatibility, and poor mechanical properties. Sustainable effectiveness, attenuation and prevention of fibrosis, and biocompatibility are key factors for the clinical application of stents to BBS treatment. In addition, loading drugs could show synergistic effects with stents' own performance. We developed a dexamethasone-eluting biodegradable stent (DBS) consisting of a sheath/core structure with outstanding mechanical properties and sustained release of dexamethasone, which maintained its functions in a BBS duct over 12 weeks in a swine model. The insertion of our DBS not only expanded BBS areas but also healed secondary ulcers as a result of the attenuation of fibrosis. After 16 weeks from the insertion, BBS areas were totally improved, and the DBS was degraded and thoroughly disappeared without re-intervention for stent removal. Our DBS would be an effective clinical tool for non-vascular diseases. STATEMENT OF SIGNIFICANCE: This study describes the insertion of a drug-eluting biodegradable stent (DBS) into the bile duct. The sheath/core structure of DBS confers substantial durability and a sustained drug release profile. Drug released from the DBS exhibited anti-fibrotic effects without inflammatory responses in both in vitro and in vivo experiments. The DBS maintained its function over 12 weeks after insertion into the common bile duct, expanding benign biliary stricture (BBS) and reducing inflammation to heal secondary ulcers in a swine BBS model. After 16 weeks from the DBS insertion, the DBS thoroughly disappeared without re-intervention for stent removal, resulting in totally improved BBS areas. Our findings not only spotlight the understanding of the sheath/core structure of the biodegradable stent, but also pave the way for the further application for non-vascular diseases.

Global prevalence of functional dyspepsia according to Rome criteria, 1990-2020: a systematic review and meta-analysis.

Although functional dyspepsia (FD) is a common functional gastroduodenal disorder with a high socioeconomic burden, little is known about its global prevalence. Thus, we performed a comprehensive study to estimate long-term trends in the prevalence of FD. We searched PubMed/MEDLINE, Embase, and Google Scholar from 1990 to 2022 for population-based studies that reported the prevalence of FD in adults (≥ 18 years old) according to Rome I, II, III, or IV criteria. The prevalence of FD was extracted from included studies to obtain pooled prevalence with 95% confidence intervals (CI) and 95% prediction intervals. Subgroup analysis was performed according to certain characteristics, including geographic region. A total of 44 studies met the eligibility criteria, including 256,915 participants from 40 countries across six continents. The overall global pooled prevalence of FD was 8.4% (95% CI 7.4-.9.5). The prevalence was the highest in Rome I (11.9%; 95% CI 5.1-25.4) and lowest in Rome IV (6.8%; 95% CI 5.8-7.9). Developing countries showed a higher prevalence than developed countries (9.1% versus 8.0%), and prevalence was higher in women, irrespective of the definition used (9.0% versus 7.0%). The pooled prevalence gradually decreased from 1990 to 2020 (12.4% [8.2-18.3] in 1990-2002 versus 7.3% [6.1-8.7] in 2013-2020). The prevalence of FD differs by country, economic status, geographical region, and sex, and the global prevalence has been gradually declining. Despite the heterogeneity of sample population, our study estimates the current global burden of FD and provides information to heath care policy decisions.

Prognostic Impact of Minimal Pelvic Fluid in Locally Advanced Pancreatic Cancer: A Multicenter Retrospective Study.

BACKGROUND/AIMS: Minimal pelvic fluid (MPF) is occasionally encountered on computed tomography (CT) scans during the initial staging of newly diagnosed pancreatic cancer. However, its clinical relevance has scarcely been studied. This study intends to explore the incidence of minimal pelvic fluid and its relevance in terms of survival in locally advanced pancreatic cancer (LAPC) patients. MATERIALS AND METHODS: The medical records of patients with LAPC at 4 tertiary referral institutions were retrospectively reviewed from January 2005 to December 2015. Minimal pelvic fluid was defined as a fluid collection volume in the pelvic cavity of <100 mL as determined by abdominal CT. The association between the presence of MPF and patient survival was evaluated. RESULTS: A total of 59 patients (male:female, 33:26; median age, 68 years; range 46-82 years) with LAPC were enrolled. Of the 59 patients, 22.0% (n = 13) had MPF, and 78.0% (n = 46) had no pelvic fluid (NPF). Baseline clinical characteristics in the 2 groups, including extent of the tumor stage, extent of spread to the lymph nodes stage, and pattern of treatments, were not significantly different. However, median overall survival was significantly less in the MPF group [9.7 months, (95% CI, 5.9-13.5)] than in the NPF group as determined by the log-rank test [16.9 months, (95% CI, 9.3-24.5)] (P = .002), and univariate and multivariate analyses showed that the presence of MPF independently predicted a poor prognosis. CONCLUSION: The presence of MPF was found to be significantly associated with reduced survival and an independent poor prognostic biomarker in LAPC patients.

Efficacy of a Newly Developed Guidewire for Selective Biliary Cannulation: A Multicenter Randomized Controlled Trial.

BACKGROUND AND AIMS: Various guidewires are used for biliary cannulation, and each one has its own characteristics affecting its effectiveness. This study aimed to measure the basic properties and evaluate the effectiveness of a newly developed 0.025-inch guidewire for selective biliary cannulation. METHODS: A total of 190 patients at five referral hospitals were randomly allocated to undergo selective biliary cannulation using the newly developed guidewire (NGW group, n = 95) or a conventional guidewire (CGW group, n = 95). The primary outcome was the selective biliary cannulation rate in naïve papillae. The secondary outcome was to measure the NGW basic properties, compare them with those of the CGW, and analyze the importance of basic property differences. RESULTS: There were no significant differences between the groups in the baseline characteristics. The primary outcome (75.8% vs. 84.2%, p = 0.102) and adverse event rate (6.3% vs. 4.2%, p = 0.374) were similar in both groups. However, compared with the CGW group, the NGW group showed a higher number of ampulla contacts (2.58 vs. 2.02, p = 0.011) and longer cannulation time (216.5 vs. 135.1 s, p = 0.016). Furthermore, the NGW group had higher maximum friction (34.6 ± 1.34 vs. 30.2 ± 4.09), lower stiffness, and better elastic resiliency. In the multivariate analysis, a curved-tip GW (OR = 0.26, 95% CI 0.11-0.62, p = 0.002) and normal papillary shape (OR = 0.39, 95% CI 0.17-0.86, p = 0.021) were contributing factors for successful selective biliary cannulation. CONCLUSIONS: The NGW group had high friction and low stiffness, characteristics affecting biliary cannulation. Clinically, the NGW group had similar success and adverse event rates as the CGW, but they showed a higher number of ampulla contacts and longer cannulation time.

Efficacy Analysis of Suprapapillary versus Transpapillary Self-Expandable Metal Stents According to the Level of Obstruction in Malignant Extrahepatic Biliary Obstruction.

Background/Aims: The use of a self-expandable metal stent (SEMS) is recommended for unresectable malignant biliary obstruction (MBO). Stent-related adverse events might differ according to the position of the stent through the ampulla of Vater (AOV). We retrospectively evaluated SEMS patency and adverse events according to the position of the SEMS. Methods: In total, 280 patients who underwent endoscopic SEMS placement due to malignant distal biliary obstruction were analyzed retrospectively. Suprapapillary and transpapillary SEMS insertions were performed on 51 patients and 229 patients, respectively. Results: Between the suprapapillary group (SPG) and transpapillary group (TPG), the stent patency period was not significantly different (median [95% confidence interval]: 107 days [82.3 to 131.7] vs 120 days [99.3 to 140.7], p=0.559). There was also no significant difference in the rate of adverse events. In subgroup analysis, the stent patency for an MBO located within 2 cm from the AOV was found to be significantly shorter than that for an MBO located more than 2 cm from the AOV in the SPG (64 days [0 to 160.4] vs 127 days [82.0 to 171.9], p<0.001) and TPG (87 days [52.5 to 121.5] vs 130 [97.0 to 162.9], p<0.001). Patients with an MBO located within 2 cm from the AOV in both groups had a higher percentage of duodenal invasion (SPG: 40.0% vs 4.9%, p=0.002; TPG: 28.6% vs 2.9%, p<0.001) than patients with an MBO located more than 2 cm from the AOV. Conclusions: The SPG and TPG showed similar results in terms of stent patency and rate of adverse events. However, patients with an MBO located within 2 cm from the AOV had a higher percentage of duodenal invasion with shorter stent patency than those with an MBO located more than 2 cm from the AOV, regardless of stent position.

Effects of Mesenchymal Stem Cells Treatment on Radiation-Induced Proctitis in Rats.

PURPOSE: There are no effective treatment methods with which to control complications of radiation proctitis with fistula or recurrent bleeding following radiation treatment for prostate, cervical, or rectal cancer. Mesenchymal stem cells (MSCs) can induce immune modification, resulting in tissue repair and regeneration. Therefore, we used a rat model of radiation-induced proctitis and observed the effects of using human placenta-derived (PD) and adipose tissue-derived (AD) MSCs. MATERIALS AND METHODS: Female Sprague Dawley rats were irradiated at the pelvic area with 25 Gy. We injected 1×106 cells of human PD-MSCs, human AD-MSCs, human foreskin fibroblasts, and control media into the rectal submucosa following irradiation. We sacrificed rats for pathologic evaluation. RESULTS: Fibrosis on the rectum was reduced in both MSC groups, compared to the control group. Mucosal Ki-67 indices of both MSC injected groups were higher than those in the control group. Although caspase-3 positive cells in the mucosa gradually increased and decreased in the control group, those in both MSC injected groups increased rapidly and decreased thereafter. CONCLUSION: We demonstrated the effects of regional MSC injection treatment for radiation-induced proctitis in rats. MSC injection reduced fibrosis and increased proliferation in rat mucosa. Human AD-MSCs and PD-MSCs had similar effectiveness.

Clinical feasibility of curative surgery after nab-paclitaxel plus gemcitabine-cisplatin chemotherapy in patients with locally advanced cholangiocarcinoma.

BACKGROUND: This study was conducted to evaluate the clinical feasibility of nab-paclitaxel plus gemcitabine-cisplatin triplet chemotherapy in patients with locally advanced cholangiocarcinoma in real-world practice. METHODS: We retrospectively reviewed patients with locally advanced cholangiocarcinoma who were treated with nab-paclitaxel plus gemcitabine-cisplatin between October 2019 and August 2021 at a single institution. The initial diagnosis of cholangiocarcinoma was histologically confirmed. RESULTS: One hundred twenty-nine patients were included in this study. Among the patients with a measurable lesion (57.4%), the objective response rate and disease control were 60.8% and 91.9%, respectively. Seventy-seven patients (59.7%) were determined as resectable after triplet chemotherapy, but 73 (56.6%) underwent subsequent curative surgery. The major postoperative complication rate was 15.1%, and there were 2 postoperative mortalities (2.7%). There were 6 complete remission cases (8.2%) in the final pathology. The R0 resection was achieved in 67 patients (91.8%). Despite the initial locally advanced cholangiocarcinoma, a pathologic T stage of less than T2 was reported in 67 patients (91.8%). Fifty-two patients (71.2%) had no lymph node metastasis. Patients who underwent surgery after triplet chemotherapy had significantly higher 12-month overall survival (95.9% vs 76.8%; P < .001) than those treated with chemotherapy alone. CONCLUSION: Nab-paclitaxel plus gemcitabine-cisplatin chemotherapy demonstrated a down-staging effect through a high response rate, indicating that this triplet chemotherapy is feasible as induction therapy in patients with locally advanced cholangiocarcinoma.

Quantum transport evidence of isolated topological nodal-line fermions.

Anomalous transport responses, dictated by the nontrivial band topology, are the key for application of topological materials to advanced electronics and spintronics. One promising platform is topological nodal-line semimetals due to their rich topology and exotic physical properties. However, their transport signatures have often been masked by the complexity in band crossings or the coexisting topologically trivial states. Here we show that, in slightly hole-doped SrAs3, the single-loop nodal-line states are well-isolated from the trivial states and entirely determine the transport responses. The characteristic torus-shaped Fermi surface and the associated encircling Berry flux of nodal-line fermions are clearly manifested by quantum oscillations of the magnetotransport properties and the quantum interference effect resulting in the two-dimensional behaviors of weak antilocalization. These unique quantum transport signatures make the isolated nodal-line fermions in SrAs3 desirable for novel devices based on their topological charge and spin transport.

The Safety and Efficacy of an Unflanged 4F Pancreatic Stent in Transpancreatic Precut Sphincterotomy for Patients with Difficult Biliary Cannulation: A Prospective Cohort Study.

Prophylactic pancreatic stenting effectively reduces the rate and severity of post-ERCP pancreatitis (PEP) in the precut technique; however, studies on the optimal type and duration of the stent are still lacking. This prospective study evaluated the incidence and severity of PEP and the rate of spontaneous stent dislodgement in patients undergoing transpancreatic precut sphincterotomy (TPS) accompanied by prophylactic pancreatic stenting with an unflanged plastic stent (4F × 5 cm) for difficult biliary cannulation. A total of 247 patients with naïve papilla were enrolled in this study, and data were collected prospectively. In the final analysis, 170 and 61 patients were included in the standard cannulation technique and TPS groups, respectively. The incidence of PEP in the standard cannulation technique and TPS groups was 3.5% and 1.6% (p = 0.679), respectively. The technical success rate of selective biliary cannulation in the TPS group was 91.8%. The spontaneous dislodgement rate of the prophylactic plastic stent was 98.4%. In conclusion, an unflanged pancreatic stent (4F × 5 cm) placement in TPS for patients with failed standard cannulation technique is a safe and effective measure due to low adverse events and few additional endoscopic procedures for removing the pancreatic duct (PD) stent.

Mechanistic loop resolution strategy for short-type single-balloon enteroscopy-assisted endoscopic retrograde cholangiopancreatography in patients with Roux-en-Y reconstruction after gastrectomy (with video).

BACKGROUND: Endoscopic access to the targeted site is a major challenge for the endoscopic retrograde cholangiopancreatography (ERCP) in patients undergoing Roux-en-Y (R-Y) reconstruction after total or subtotal gastrectomy. We aimed to evaluate the feasibility, reproducibility, and safety of mechanistic loop resolution strategies using a short-type single-balloon enteroscopy (short SBE) system. METHODS: Between February 2020 and March 2022, consecutive patients with a previous R-Y gastrectomy requiring ERCP were prospectively enrolled. Different mechanistic loop resolution strategies for two-dimensional loops, three-dimensionally rotated loops, and loops making a cane or S-shape were applied during the SBE approach. RESULTS: Forty-three short SBE-ERCP procedures were performed on 37 patients, with an approach success rate of 100.0% (43/43). The mean time to reach the jejunojejunal anastomosis and target site were 8.0 (6.0-11.0) minutes and 26.0 (16.0-36.0) minutes, respectively. The major challenges for the approach were the cane or S-shaped loop in the jejunojejunal anastomosis or Treitz ligament. The retroflex positioning of a SBE in front of the papilla was achieved in 86.0% (37/43), and the cannulation success rate in patients with an intact papilla was 90.9% (30/33). The initial, overall therapeutic successes, median total procedure time, and adverse event rate were 87.8%, 92.7%, 77.0 (IQR 56-100.5) minutes, and 11.6%, respectively. CONCLUSIONS: Short SBE-ERCP using standardized mechanistic loop resolution strategies is effective and reproducible in patients with R-Y reconstruction after gastrectomy. TRIAL REGISTRATION: ClinicalTrial.gov (NCT04847167).

Optimal reproduction of a porcine benign biliary stricture model using endobiliary radiofrequency ablation.

The use of endobiliary radiofrequency ablation (RFA) to generate a benign biliary stricture (BBS) model has a significant reproducibility problem. The aims of this animal study were to create an optimal BBS model using endobiliary RFA and determine the best way to develop it. The first step was performed on the common bile duct (CBD) of 10 miniature pigs using endoscopic RFA with a target temperature-controlled mode (80 â„ƒ, 7 W for 90 s). The second step was performed on the CBD of five miniature pigs to understand more about the time-dependent changes in BBS development and the causes of adverse events. Using the conditions and techniques identified in the previous steps, the third step was conducted to create an optimal BBS model in 12 miniature pigs. In the first trial, four out of 10 animals died (40%) after the procedure due to cholangitis-induced sepsis. Based on this, biliary obstruction was prevented in further steps by placing a biliary plastic stent after RFA application. Histologic examinations over time showed that a severe abscess developed at the RFA application site on the fifth day, followed by fibrosis on the tenth day, and completion on the twentieth day. In the third trial, 11 animals survived (91.7%), the average BBS fibrotic wall thickness was 1107.9 µm (763.1-1864.6 µm), and the degree of upstream biliary dilation was 14.4 mm (11.05-20.7 mm). In conclusion, endobiliary RFA combined with a biliary plastic stent resulted in a safe and reproducible BBS animal model.

Inhibitory Effect of Mitoxantrone on Collagen Synthesis in Dermal Fibroblasts.

Background: Fibroblasts produce collagen molecules that support the structure of the skin. The decrease and hypersynthesis of collagen causes skin problems such as skin atrophy, wrinkles and scars. Objective: The purpose of this study is to investigate the mechanism of mitoxantrone on collagen synthesis in fibroblasts. Methods: Cultured fibroblasts were treated with mitoxantrone, and then collagen synthesis was confirmed by reverse transcription-polymerase chain reaction and Western blot. Results: Mitoxantrone inhibited the expression of type I collagen in fibroblasts at both the mRNA and protein levels. In the collagen gel contraction assay, mitoxantrone significantly inhibited gel contraction compared to the control group. Mitoxantrone inhibited transforming growth factor (TGF)-ß-induced phosphorylation of SMAD3. Finally, mitoxantrone inhibited the expression of LARP6, an RNA-binding protein that regulates collagen mRNA stability. Conclusion: These results suggest that mitoxantrone reduces collagen synthesis by inhibiting TGF-ß/SMAD signaling and LARP6 expression in fibroblasts, which can be developed as a therapeutic agent for diseases caused by collagen hypersynthesis.

Bullous Variant of Pyoderma Gangrenosum in a Patient with Acute Myeloid Leukemia.

Unlike classic pyoderma gangrenosum (PG), the bullous variant of PG is typically represented by a painful erythematous papule, plaque, and superficial bulla that progress into the ulceration with bullous margin. Generally, bullous PG is most commonly associated with myeloproliferative disorders, such as acute myeloid leukemia (AML). Bullous PG in AML patients rarely occurs, but once it does, it suggests a poor clinical prognosis. Although many cases of classic PG in AML patients have been reported, bullous PG is relatively rare. Therefore, we present a case of bullous PG that developed in a patient with AML and was successfully treated with high-dose systemic steroids.