New gel immersion endoscopic ultrasonography technique for accurate periampullary evaluation.

BACKGROUND: Visualization of the pancreatobiliary junction is one of the challenges faced by endoscopic ultrasonography (EUS). The water-filling technique, which allows for the observation of the ampulla at a suitable distance by injecting water into the lumen of the duodenum, was used for this purpose. However, a new gel immersion technique has recently been introduced for visualizing the gastrointestinal tract. This study investigated the effectiveness of visualizing the pancreatobiliary junction in EUS by comparing both water filling and the new gel immersion technique in identical cases. METHODS: The study ran from June to December 2021. Ten images from each technique were retrospectively compared by three independent researchers. The primary result of the study was the number of images depicting the "Pancreatic and Biliary Ducts Penetrating the Duodenal Muscularis Propria" (defined as Excellent observation) in each technique. The secondary outcome was defined as gel immersion technique's safety and impact on duodenal lumen distension. RESULTS: Ten patients used the gel immersion technique. All patients underwent the water-filling technique first, followed by gel injection after the water was completely aspirated. The average number of pictures rated as "Excellent observation," which is the primary outcome, was significantly higher with the gel immersion technique than with water filling, and no adverse events were observed. The subanalysis revealed that both convex and radial echoendoscopes are equally effective at depicting the ampulla with the gel immersion technique. CONCLUSIONS: The ability to depict the pancreatobiliary junction using the gel immersion technique is superior to that of the water-filling method, which may allow for a more detailed assessment of the ampullary region with both radial and convex echoendoscopes. This can be a useful EUS technique for diagnosing pancreaticobiliary maljunction or periampullary tumors.

Prognostic significance of skeletal muscle decrease in unresectable pancreatic cancer: Survival analysis using the Weibull exponential distribution model.

BACKGROUND/OBJECTIVES: Decrease in skeletal muscle mass and function is associated with a poor prognosis following surgical resection of pancreatic ductal adenocarcinomas (PDAs). This study evaluated whether skeletal muscle mass decrease affects PDA outcomes. METHODS: Data of 112 patients with advanced and unresectable PDA who underwent chemotherapy in a single institution were retrospectively analyzed. Information on age, sex, hematological investigations, including systemic inflammation-based markers and nutritional assessment biomarkers, and imaging parameters of skeletal muscle mass and visceral adipose tissue were retrieved from the patients' medical records. The efficiency of the Cox, Weibull, and standardized exponential models were compared using hazard ratios and the Akaike Information Criterion (AIC). RESULTS: Results from the Weibull, Cox, and standardized exponential model analyses indicated that low skeletal muscle mass, Eastern Cooperative Oncology Group performance status (PS), and the requirement of biliary drainage were associated with the highest risk of death, followed by carcinoembryonic antigen (CEA) levels and the presence of ascites. The AIC value from the four significant parameters was lowest for the Weibull-exponential distribution (222.3) than that of the Cox (653.7) and standardized exponential models (265.7). We developed a model for estimating the 1-year survival probability using the Weibull-exponential distribution. CONCLUSIONS: Low-skeletal muscle index, PS, requirement of biliary drainage, CEA levels, and presence of ascites are independent factors for predicting poor patient survival after chemotherapy. Improved survival modeling using a parametric approach may accurately predict the outcome of patients with advanced-stage PDA.

The Lambda stenting technique: a new approach to address EUS-guided biliary drainage-associated adverse events.

Background and Aims: EUS-guided biliary drainage (EUS-BD) has been performed increasingly worldwide, especially in patients with malignant tumors in which ERCP is difficult, patients with surgically altered GI tracts, and older patients who are at high risk for surgery. EUS-BD requires high-level skills and has limited options for managing adverse events, particularly when stent migration and cholangitis occur. Adverse events, such as persistent bile leakage from the fistula and continuous reflux from the GI tract, are believed to always have a risk of severe exacerbation that could threaten the patient's life. Methods: We encountered 2 cases of stent migrations and 1 case with repeated cholangitis in patients with malignant tumors among the patients who underwent EUS-BD. The migrated stent was visualized under EUS in 2 patients with stent migration, and an EUS-guided FNA needle was used to puncture the mesh of the stent. The cannulation catheter was directly inserted into the mesh of the stent in 1 case with repeated retrograde cholangitis, while the stent was visualized with an endoscope. Subsequently, a guidewire was inserted through the puncture site, and a second metal stent was deployed between the meshes of the first stent, bridging the GI wall again (Lambda stenting technique). All procedures were performed with the patient under general anesthesia, and the patients safely completed the intervention. Results: Patients' conditions significantly improved after the second stent insertion, allowing for chemotherapy resumption while maintaining their activities of daily living. The second stent remained in place without any migration, and the stent successfully prevented further cholangitis. Conclusions: The Lambda stenting technique is considered highly effective for managing stent migration and repeated cholangitis, which is a major EUS-BD adverse event. This procedure helps avoid more invasive surgeries when stent migration and cholangitis occur and contributes to expanding EUS-BD applicability.

Small Insulinoma Followed-up as an Indolent Pancreatic Tumor: A Case Report.

A woman in her 60s presented with a small pancreatic head tumor. Imaging studies revealed a 13-mm well-defined pancreatic head tumor. A neuroendocrine neoplasm was suspected, and the patient opted for observation at that time. After 8 months, the patient began experiencing sweating while fasting, and blood tests during regular follow-up visits showed hypoglycemia. Hypoglycemia was induced during fasting test. The tumor exhibited clear features of an insulinoma during follow-up observation. While small neuroendocrine neoplasms are often managed through observation, caution should be exercised regarding their transformation into functional neuroendocrine tumors.

Liquid Biopsy for Pancreatic Cancer by Serum Extracellular Vesicle-Encapsulated Long Noncoding RNA HEVEPA.

OBJECTIVES: The role of long noncoding RNAs (lncRNAs) in pancreatic ductal adenocarcinoma (PDAC) remain unclear. Extracellular vesicle (EV)-encapsulated RNAs could be effective targets for liquid biopsy. We aimed to identify previously unknown EV-encapsulated lncRNAs in PDAC and establish highly accurate methods for isolating EVs. MATERIALS AND METHODS: Extracellular vesicles were isolated using existing and newly developed methods, namely, PEViA-UC and PEViA-IP, from serum samples of 20 patients with PDAC, 22 patients with intraductal papillary mucinous neoplasms, and 21 healthy individuals. Extracellular vesicle lncRNA expression was analyzed using digital PCR. RESULTS: Gene expression analysis using cDNA microarray revealed a highly expressed lncRNA, HEVEPA , in serum EVs from patients with PDAC. We established PEViA-UC and PEViA-IP using PEViA reagent, ultracentrifugation, and immunoprecipitation. Although detection of EV-encapsulated HEVEPA using existing methods is challenging, PEViA-UC and PEViA-IP detected EV HEVEPA , which was highly expressed in patients with PDAC compared with non-PDAC patients. The detection sensitivity for discriminating PDAC from non-PDAC using the combination of HEVEPA and HULC , which are highly expressed lncRNAs in PDAC, and carbohydrate antigen 19-9 (CA19-9), was higher than that of HEVEPA , HULC , or CA19-9 alone. CONCLUSIONS: Extracellular vesicle lncRNAs isolated using PEViA-IP and CA19-9 together could be effective targets in liquid biopsy for PDAC diagnosis.

Risk factors for recurrent biliary obstruction following endoscopic biliary stenting in patients with unresectable ampullary cancer: A multicenter retrospective study.

OBJECTIVES: Unresectable ampullary cancer (AC) is a rare disease entity. The risk factors for recurrent biliary obstruction (RBO) following endoscopic biliary stenting (EBS) for unresectable AC remain unknown. In this study we aimed to evaluate the cumulative RBO rate and to identify risk factors for RBO following palliative EBS in patients with unresectable AC. METHODS: This multicenter retrospective observational study enrolled consecutive patients with unresectable AC who had undergone palliative EBS between April 2011 and December 2021. The cumulative rate of and risk factors for RBO following palliative EBS were evaluated via multivariate analysis. RESULTS: The study analysis comprised 107 patients with a median age of 84 years (interquartile range 79-88 years). Plastic stents (PSs) and self-expandable metal stents (SEMSs) were placed in 53 and 54 patients, respectively. Functional success was accomplished in 104 (97.2%) patients. Of these, RBO occurred in 62 (59.6%) patients, with obstruction and complete/partial migration occurring in 47 and 15 patients, respectively. The median time to RBO was 190 days. Multivariate analysis showed that PS was associated with a higher rate of RBO compared to SEMS (hazard ratio [HR] 2.48; P < 0.01) and that the presence of common bile duct stones/sludge immediately after EBS was an independent risk factor for RBO (HR 1.99; P = 0.04). CONCLUSIONS: The use of SEMS compared to PS during EBS reduced the time to RBO in patients with unresectable AC. Common bile duct stones/sludge immediately after EBS was a risk factor for RBO.

The Effectiveness of the Combination of Arterial Infusion Chemotherapy and Radiotherapy for Biliary Tract Cancer: A Prospective Pilot Study.

The standard treatment of unresectable biliary tract cancer (BTC) has shown an insufficient response rate (RR). Our retrospective setting revealed that a combination therapy consisting of intra-arterial chemotherapy plus radiation therapy (IAC + RT) provided a high RR and long-term survival benefits in unresectable BTC. This prospective study aimed to test the effectiveness and safety of IAC + RT as the first-line therapy. The regimen included one-shot IAC with cisplatin, 3-6 months of reservoir IAC (5-FU and cisplatin, q/week), and 50.4 Gy of external radiation. The primary endpoints include the RR, disease control rate, and adverse event rate. This study included seven patients with unresectable BTC without distant metastasis, with five cases classified as stage 4. RT was completed in all cases, and the median number of reservoir IAC sessions was 16. The RR was 57.1% for imaging and 71.4% for clinical assessment, and the disease control rate was 100%, indicating a high antitumor efficacy, which allowed two cases to be transferred to surgery. Five cases of leukopenia and neutropenia; four cases of thrombocytopenia; and two cases of hemoglobin depletion, pancreatic enzyme elevation, and cholangitis were observed, but with no treatment-related deaths. This study revealed a very high antitumor effect with IAC + RT for some unresectable BTC, and it could be useful for conversion therapy.

Multiplex Digital PCR Assay to Detect Multiple KRAS and GNAS Mutations Associated with Pancreatic Carcinogenesis from Minimal Specimen Amounts.

Digital PCR (dPCR) allows for highly sensitive quantification of low-frequency mutations and facilitates early detection of cancer. However, low-throughput targeting of single hotspots in dPCR hinders variant specification when multiple probes are used. We developed a dPCR method to simultaneously identify major variants related to pancreatic carcinogenesis. Using a two-dimensional plot of droplet fluorescence under the optimized concentration of two fluorescent probe pools, the absolute quantification of different KRAS and GNAS variants was determined. Successful detection of the multiple driver mutations was verified in 24 surgically resected tumor samples from 19 patients and 22 fine-needle aspiration samples from patients with pancreatic ductal adenocarcinoma. Precise quantification of the variant allele frequency was optimized by using template DNA at a concentration as low as 1 to 10 ng. Furthermore, amplicons targeting multiple hotspots were successfully enriched with fewer false-positive findings using high-fidelity polymerase, allowing for the detection of various KRAS and GNAS mutations with high probability in small amount of cell/tissue specimens. Using this target enrichment, mutations at a rate of 90% in small residual tissues, such as the fine-needle aspiration needle flush and microscopic lesions in resected specimens, were successfully identified. The proposed method allows for low-cost, accurate detection of driver mutations to diagnose cancers, even with minimal tissue collection.

Mutant GNAS limits tumor aggressiveness in established pancreatic cancer via antagonizing the KRAS-pathway.

BACKGROUND: Mutations in GNAS drive pancreatic tumorigenesis and frequently occur in intraductal papillary mucinous neoplasm (IPMN); however, their value as a therapeutic target is yet to be determined. This study aimed at evaluating the involvement of mutant GNAS in tumor aggressiveness in established pancreatic cancer. METHODS: CRISPR/Cas9-mediated GNAS R201H silencing was performed using human primary IPMN-associated pancreatic cancer cells. The role of oncogenic GNAS in tumor maintenance was evaluated by conducting cell culture and xenograft experiments, and western blotting and transcriptome analyses were performed to uncover GNAS-driven signatures. RESULTS: Xenografts of GNAS wild-type cells were characterized by a higher Ki-67 labeling index relative to GNAS-mutant cells. Phenotypic alterations in the GNAS wild-type tumors resulted in a significant reduction in mucin production accompanied by solid with massive stromal components. Transcriptional profiling suggested an apparent conflict of mutant GNAS with KRAS signaling. A significantly higher Notch intercellular domain (NICD) was observed in the nuclear fraction of GNAS wild-type cells. Meanwhile, inhibition of protein kinase A (PKA) induced NICD in GNAS-mutant IPMN cells, suggesting that NOTCH signaling is negatively regulated by the GNAS-PKA pathway. GNAS wild-type cells were characterized by a significant invasive property relative to GNAS-mutant cells, which was mediated through the NOTCH regulatory pathway. CONCLUSIONS: Oncogenic GNAS induces mucin production, not only via MUC2 but also via MUC5AC/B, which may enlarge cystic lesions in the pancreas. The mutation may also limit tumor aggressiveness by attenuating NOTCH signaling; therefore, such tumor-suppressing effects must be considered when therapeutically inhibiting the GNAS pathway.

Damage control surgery for grade IV blunt hepatic injury with multiple organ damage in a child: a case report.

BACKGROUND: Intra-abdominal hemorrhage caused by blunt hepatic injury is a major cause of morbidity and mortality in patients with abdominal trauma. Some of these patients require laparotomy, and rapid decision-making and life-saving surgery are essential. Damage control (DC) surgery is useful for treating children in critical situations. We performed this technique to treat an 8-year-old boy with grade IV blunt hepatic injury and multiple organ damage. This is the first report of the use of the ABTHERA Open Abdomen Negative Pressure Therapy System (KCI, now part of 3 M Company, San Antonio, TX, USA) for DC surgery to rescue a patient without neurological sequelae. CASE PRESENTATION: An 8-year-old boy was brought to the emergency department of our hospital after being run over by a motor vehicle. He had grade IV blunt hepatic injury, thyroid injury, and bilateral hemopneumothorax. Although he was hemodynamically stable, the patient's altered level of consciousness, the presence of a sign of peritoneal irritation, and suspicion of intestinal injury led us to perform exploratory laparotomy. As part of a DC strategy, we performed gauze packing to control hemorrhage from the liver and covered the abdomen with an ABTHERA Open Abdomen Negative Pressure Therapy System to improve the patient's general condition. Eighteen days after admission, the patient was diagnosed with a biliary fistula, which improved with percutaneous and external drainage. He had no neurological sequelae and was discharged 102 days after injury. CONCLUSION: The DC strategy was effective in children with severe blunt hepatic injury. We opted to perform DC surgery because children have less hemodynamic reserve than adults, and we believe that using this strategy before the appearance of trauma triad of death could save lives and improve outcomes. During conservative management, it is important to adopt a multistage, flexible approach to achieve a good outcome.

Time-saving method for directly amplifying and capturing a minimal amount of pancreatic tumor-derived mutations from fine-needle aspirates using digital PCR.

It is challenging to secure a cytopathologic diagnosis using minute amounts of tumor fluids and tissue fragments. Hence, we developed a rapid, accurate, low-cost method for detecting tumor cell-derived DNA from limited amounts of specimens and samples with a low tumor cellularity, to detect KRAS mutations in pancreatic ductal carcinomas (PDA) using digital PCR (dPCR). The core invention is based on the suspension of tumor samples in pure water, which causes an osmotic burst; the crude suspension could be directly subjected to emulsion PCR in the platform. We examined the feasibility of this process using needle aspirates from surgically resected pancreatic tumor specimens (n = 12). We successfully amplified and detected mutant KRAS in 11 of 12 tumor samples harboring the mutation; the positive mutation frequency was as low as 0.8%. We used residual specimens from fine-needle aspiration/biopsy and needle flush processes (n = 10) for method validation. In 9 of 10 oncogenic KRAS pancreatic tumor samples, the "water-burst" method resulted in a positive mutation call. We describe a dPCR-based, super-sensitive screening protocol for determining KRAS mutation availability using tiny needle aspirates from PDAs processed using simple steps. This method might enable pathologists to secure a more accurate, minimally invasive diagnosis using minute tissue fragments.

Resection for pancreatic cancer metastases contributes to survival: A case report with sequential tumor genotype profiling during the long-term postoperative course.

INTRODUCTION: Surgical management is not a standard treatment option for metastatic recurrence of pancreatic adenocarcinoma. However, the surgical management of a solitary metastasis is useful in selected cases. PATIENT CONCERNS: A 42-year-old woman was referred to our hospital on account of epigastric pain associated with a mass in the pancreatic body. The patient had a family history of branch duct-type intraductal papillary mucinous neoplasm of the pancreas. DIAGNOSIS: The patient was diagnosed with pancreatic ductal adenocarcinoma (PDA) complicated with pancreatitis due to pancreatic duct involvement. INTERVENTIONS: The patient underwent distal pancreatectomy, and pathological examination revealed a tubular adenocarcinoma. Solitary liver and lung metastatic tumors were found 6 and 43 months after the initial presentation, respectively, and sequential metastasectomies were performed. OUTCOMES: The patient survived until 8 years after her initial presentation. The genetic profiles of the resected specimens, primary PDA, and recurrent tumors in the liver and lung possessed identical KRAS mutations at codon 12, whereas there were no mutations in the main tumor suppressor genes, such as TP53, CDKN2A, and SMAD4. Multiplex polymerase chain reaction-based microsatellite instability assay demonstrated microsatellite stability. CONCLUSION: In our case, the patient with pancreatic adenocarcinoma survived for over 8 years following the resection of the primary tumor and resections of metachronous metastatic tumors. The outcome of PDA may be associated with the genetic profile that regulates its biological behavior. Operative management of solitary metastatic tumors may be a therapeutic options for selected patients with pancreatic cancer.

Digital PCR-based plasma cell-free DNA mutation analysis for early-stage pancreatic tumor diagnosis and surveillance.

BACKGROUND: Cell-free DNA (cfDNA) shed from tumors into the circulation offers a tool for cancer detection. Here, we evaluated the feasibility of cfDNA measurement and utility of digital PCR (dPCR)-based assays, which reduce subsampling error, for diagnosing pancreatic ductal adenocarcinoma (PDA) and surveillance of intraductal papillary mucinous neoplasm (IPMN). METHODS: We collected plasma from seven institutions for cfDNA measurements. Hot-spot mutations in KRAS and GNAS in the cfDNA from patients with PDA (n = 96), undergoing surveillance for IPMN (n = 112), and normal controls (n = 76) were evaluated using pre-amplification dPCR. RESULTS: Upon Qubit measurement and copy number assessment of hemoglobin-subunit (HBB) and mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1 (MT-ND1) in plasma cfDNA, HBB offered the best resolution between patients with PDA relative to healthy subjects [area under the curve (AUC) 0.862], whereas MT-ND1 revealed significant differences between IPMN and controls (AUC 0.851). DPCR utilizing pre-amplification cfDNA afforded accurate tumor-derived mutant KRAS detection in plasma in resectable PDA (AUC 0.861-0.876) and improved post-resection recurrence prediction [hazard ratio (HR) 3.179, 95% confidence interval (CI) 1.025-9.859] over that for the marker CA19-9 (HR 1.464; 95% CI 0.674-3.181). Capturing KRAS and GNAS could also provide genetic evidence in patients with IPMN-associated PDA and undergoing pancreatic surveillance. CONCLUSIONS: Plasma cfDNA quantification by distinct measurements is useful to predict tumor burden. Through appropriate methods, dPCR-mediated mutation detection in patients with localized PDA and IPMN likely to progress to invasive carcinoma is feasible and complements conventional biomarkers.

Genetic analysis of postoperative recurrence of pancreatic cancer potentially owing to needle tract seeding during EUS-FNB.

Background and study aims Needle tract seeding during endoscopic ultrasound fine-needle biopsy (EUS-FNB) remains a concern. We investigated whether such seeding occurred in a patient with pancreatic ductal adenocarcinoma (PDA). Patient and methods Surgically resected and EUS-FNB-derived specimens were genotyped to determine if a gastric wall tumor that emerged 3 years after curative resection of an early-stage PDA was clonally related to the original tumor. Results The gastric tumor histologically resembled the primary PDA; the lesions also shared KRAS , SMAD4 , and RNF43 mutations. Genotyping of the preoperative EUS-FNB specimen, in which cancer was not detected, nevertheless revealed mutations that were identical to those in the resected primary and recurrent tumors. While the primary PDA had a low frequency of mutant SMAD4 , such mutations were highly prevalent in both the EUS-FNB and recurrent tumor specimens. Conclusions The genetic lineages of sampled tissues from our patient revealed that needle tract seeding may have incidentally occurred when a subset of neoplastic cells within a heterogeneous tumor ( i. e. , an aggressive clone) was targeted during EUS-FNB.

Utility of "liquid biopsy" using pancreatic juice for early detection of pancreatic cancer.

Background Despite advances in the diagnosis of pancreatic ductal adenocarcinoma (PDA), histological evaluation of small and poorly defined masses in the pancreas is uncomfortable and unsafe. Methods We herein report a case of early stage PDA, in which multiple KRAS mutations were detected in the pancreatic juice preoperatively. A small hypoechoic area adjacent to the portal vein was detected through endoscopic ultrasound in the pancreatic body. KRAS mutations were evaluated using plasma, and the pancreatic juice by digital PCR. Results Pancreatic duct biopsy and pancreatic juice cytology were performed with no evidence of malignancy; however, KRAS mutations, KRAS G12V and G12D, were detected in the pancreatic juice. Histological assessment of the resected specimen demonstrated a solid tumor with desmoplastic reaction accompanied by carcinoma in situ in the main pancreatic duct where KRAS G12V mutation was identified. More detailed analysis demonstrated KRAS G12D mutation in the cluster of low grade pancreatic intraepithelial neoplasia, implying that the lesion developed independently. Conclusions Our study indicates the potential of "endoscopic liquid biopsy" to capture the driver gene for PDA diagnosis.

A high-throughput sequence analysis of Japanese patients revealed 11 candidate genes associated with type 1 autoimmune pancreatitis susceptibility.

The pathogenesis of autoimmune pancreatitis is unknown. In the present study we used high-throughput sequencing with next generation sequencing to identify the candidate genes associated with AIP. A total of 27 type 1 AIP patients and 30 healthy blood donors were recruited, and DNA samples were isolated from their mononuclear cells. A high-throughput sequencer with an original custom panel of 1031 genes was used to detect the genetic variants in each sample. Polymorphisms of CACNA1S (c.4642C>T), rs41554316, rs2231119, rs1042131, rs2838171, P2RX3 (c.195delG), rs75639061, SMAD7 (c.624delC) and TOP1 (c.2007delG), were identified as candidate genetic variants in patients with type 1 AIP. P2RX3 and TOP1 were significantly associated with AIP, even after adjusting bay means of Bonferroni's correction. In addition, we also identified eight candidate genetic variants that were associated with the relapse of type 1 AIP, namely: rs1143146, rs1050716, HLA-C (c.759_763delCCCCCinsTCCCG), rs1050451, rs4154112, rs1049069, CACNA1C (c.5996delC) and CXCR3 (c.630_631delGC). Finally polymorphisms of rs1050716 and rs111493987 were identified as candidate genetic variants associated with extra-pancreatic lesions in patients with type 1 AIP. These candidates might be used as markers of AIP susceptibility and could contribute to the pathogenesis of type 1 AIP.