Virtual indigo carmine chromoendoscopy images: A novel modality for peroral cholangioscopy using artificial intelligence technology (with video).

BACKGROUND AND AIMS: Accurately diagnosing biliary strictures is crucial for surgical decisions, and although peroral cholangioscopy (POCS) aids in visual diagnosis, diagnosing malignancies or determining lesion margins via this route remains challenging. Indigo carmine is commonly used to evaluate lesions during gastrointestinal endoscopy. We aimed to establish the utility of virtual indigo carmine chromoendoscopy (VICI) converted from POCS images using artificial intelligence. METHODS: This single-center, retrospective study analyzed 40 patients with biliary strictures who underwent POCS using white light imaging (WLI) and narrow-band imaging (NBI). A "cycle-consistent adversarial network" (CycleGAN) was used to convert the WLI into VICI of POCS images. Three experienced endoscopists evaluated WLI, NBI, and VICI via POCS in all patients. The primary outcome was the visualization quality of surface structures, surface microvessels, and lesion margins. The secondary outcome was diagnostic accuracy. RESULTS: VICI showed superior visualization of the surface structures and lesion margins compared with WLI (P<0.001) and NBI (P<0.001). The diagnostic accuracies were 72.5%, 87.5%, and 90.0% in WLI alone, WLI and VICI simultaneously, and WLI and NBI simultaneously, respectively. WLI and VICI simultaneously tended to result in higher accuracy than WLI alone (P=0.083) and the results were not significantly different from WLI and NBI simultaneously (P=0.65). CONCLUSIONS: VICI in POCS proved valuable for visualizing surface structures and lesion margins and contributed to higher diagnostic accuracy comparable to NBI. In addition to NBI, VICI may be a novel supportive modality for POCS.

Cysts or necrotic components in pancreatic ductal adenocarcinoma is associated with the risk of EUS-FNA/B complications including needle tract seeding.

BACKGROUND: EUS-FNA/B for pancreatic ductal adenocarcinoma (PDAC) is generally considered to be safe; however, while the incidence is low, there are occurrences of complications. Among these complications, there are serious ones like needle tract seeding (NTS), and it is not known than which types of tumors have the risks of EUS-FNA/B complications. This study aimed to evaluate the risk of EUS-FNA/B complications in patients with PDAC, focusing on morphological features. METHODS: Overall, 442 patients who underwent EUS-FNA/B for solid pancreatic masses between January 2018 and May 2022 in four institutions were retrospectively surveyed. Finally, 361 patients histopathologically diagnosed with PDAC were analyzed. Among these patients, 79 tumors with cysts or necrotic components were compared with 282 tumors without cysts or necrotic components. The incidence and risk of EUS-FNA/B complications including NTS were evaluated. RESULTS: There were 9 (2.4 %) of total EUS-FNA/B complications and 3 (0.8 %) of NTS. The incidence of total complication rate and NTS in tumors with cysts or necrotic components were significantly higher than in those without cysts or necrotic components (total complication 6.3 % vs. 1.4 %, p = 0.026, NTS 3.7 % vs. 0 %, p = 0.01). The transgastric route of puncture (OR: 93.3, 95 % CI: 3.81-2284.23) and the existence of cysts or necrotic components (OR: 7.3, 95 % CI: 1.47-36.19) were risk factors for EUS-FNA/B complications identified by the multivariate analysis. CONCLUSIONS: We should pay attention to the risks of EUS-FNA/B complications, including NTS, when the tumor has cysts or necrotic components.

Association between BRCA Gene Variants and the Response to Modified FOLFIRINOX in Patients with Unresectable Pancreatic Cancer.

We investigated the effect of modified FOLFIRINOX (mFFX) in unresectable pancreatic cancer by retrospectively analyzing the cases of 43 patients who underwent BRCA testing (germline, n=11; somatic, n=26; both germline and somatic, n=6). The association between BRCA mutations and therapeutic effect was clarified. Six patients tested positive for germline pathogenic variants. Familial pancreatic cancer (33% vs. 3%, p=0.006) and peritoneal disseminated lesions (66% vs. 8%, p<0.001) were significantly more common in patients with germline pathogenic variants. The partial response (PR) rate was 100% in the germline BRCA-positive patients, and 27% in the germline BRCA-negative patients (p<0.001). The median progression-free survival (PFS) was not reached for any germline BRCA-positive patients but was 9.0 months for the germline BRCA-negative patients (p=0.042). Patients with stage IV BRCA-associated pancreatic cancer had better overall survival than those with non-BRCA-associated pancreatic cancer, although the difference was nonsignificant (not reached vs. 655 days, p=0.061). Our results demonstrate that a PR and prolonged PFS can be expected in germline BRCA-positive patients after treatment with mFFX. Our findings also suggest that germline BRCA pathogenic variants may be useful as biomarkers for the therapeutic effect of mFFX in patients with pancreatic cancer.

Optimal liver drainage rate for survival in patients with unresectable malignant hilar biliary obstruction using 3D-image volume analyzer.

Background: Drainage exceeding 50% of total liver volume is a beneficial prognostic factor in patients with unresectable malignant hilar biliary obstruction (UMHBO). However, it is unclear what threshold percentage of total liver volume drained ('liver drainage rate') significantly improves survival in patients with UMHBO who received systemic chemotherapy. Objectives: We aimed to assess the optimal liver drainage rate that improves survival in patients with UMHBO receiving chemotherapy using a three-dimensional (3D)-image volume analyzer. Design: This study was a single-center retrospective cohort study. Methods: Data from 90 patients with UMHBO who received chemotherapy after endoscopic biliary drainage using metal stents at Okayama University Hospital from January 2003 to December 2020 were reviewed. The liver drainage rate was calculated by dividing the drained liver volume by the total liver volume using a 3D-image volume analyzer. The primary endpoint was overall survival by liver drainage rate. The secondary endpoints were time to recurrent biliary obstruction (TRBO) and prognostic factors. Results: The median total liver volume was 1172 (range: 673-2032) mL, and the median liver drainage rate was 83% (range: 50-100). Overall survival was 376 (95% CI: 271-450) days, and patients with >80% drainage (n = 67) had significantly longer survival than those with <80% drainage (n = 23) (450 days versus 224 days, p = 0.0033, log-rank test). TRBO was 201 (95% CI: 155-327) days and did not differ significantly by liver drainage rate. Multivariate Cox proportional hazards regression analysis revealed >80% liver drainage [hazard ratio (HR): 0.35, 95% CI: 0.20-0.62, p = 0.0003] and hilar cholangiocarcinoma (HR: 0.30, 95% CI: 0.17-0.50, p < 0.0001) as significant prognostic factors. Conclusion: In patients with UMHBO scheduled for chemotherapy, >80% drainage is associated with improved survival. Further prospective multicenter studies are needed to verify the results of this study. Trail registration: Okayama University Hospital, IRB number: 2108-011.

Gastric linitis plastica with autoimmune pancreatitis diagnosed by an endoscopic ultrasonography-guided fine-needle biopsy: A case report.

BACKGROUND: Gastric linitis plastica (GLP) is a subset of gastric cancer with a poor prognosis. It is difficult to obtain a definitive diagnosis by endoscopic mucosal biopsies, and the usefulness of an endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) for GLP has been recently reported. Meanwhile, autoimmune diseases are occasionally known to coexist with malignant tumors as paraneoplastic syndrome. We herein report the usefulness of an EUS-FNB for detecting GLP and the possibility of paraneoplastic syndrome coexisting with GLP. CASE SUMMARY: An 81-year-old man was admitted to our hospital for a 1-mo history of epigastric pain that increased after eating. His laboratory data revealed high levels of serum carbohydrate antigen 19-9 and immunoglobulin-G4. Endoscopic examinations showed giant gastric folds and reddish mucosa; however, no epithelial changes were observed. The gastric lumen was not distensible by air inflation, suggesting GLP. Computed tomography showed the thickened gastric wall, the diffuse enlargement of the pancreas, and the peripancreatic rim, which suggested autoimmune pancreatitis (AIP) coexisting with GLP. Because the pathological findings of the endoscopic biopsy showed no malignancy, he underwent an EUS-FNB and was diagnosed with GLP. He received chemotherapy for unresectable gastric cancer due to peritoneal metastasis, after which both the gastric wall thickening and diffuse enlargement of the pancreas were improved. CONCLUSION: An EUS-FNB for GLP with a negative endoscopic biopsy is useful, and AIP may develop as a paraneoplastic syndrome.

A case of endoscopic retrograde cholangiopancreatography-related main pancreatic duct perforation salvaged by endoscopic ultrasonography-guided pancreatic duct drainage.

We herein report a 78-year-old man who underwent endoscopic retrograde cholangiopancreatography (ERCP) to examine main pancreatic duct (MPD) stenosis. During ERCP, MPD perforation occurred due to the cytology brush maneuver. Endoscopic pancreatic stenting to bridge the perforated site failed because the MPD was bent and formed a loop. Thus, we placed the stent at the proximal perforated side. The patient developed retroperitoneal perforation and pancreatic fistula with infection, showing a worsening condition. Pancreatic duct drainage was not effective, so we performed endoscopic ultrasonography-guided pancreatic duct drainage. Subsequently, he gradually improved and was discharged 3 months after initial ERCP.

Endoscopic removal of proximally migrated stents using a double-balloon enteroscope in patients with bowel reconstruction (with video).

Endoscopic migrated stent removal using a balloon-assisted enteroscope is technically difficult in patients with bowel reconstruction. We report the treatment outcomes and endoscopic removal methods for migrated stents using a double-balloon enteroscope (DBE). We retrospectively studied 12 patients with stent migration into the main pancreatic duct (MPD) or bile duct who underwent bowel reconstruction between January 2012 and June 2020. The successful removal rates in the MPD (n = 3) and the bile duct (n = 9) were 66.7% (2/3) and 88.9% (8/9), respectively. The removal techniques included the indirect method (n = 3), the direct method (n = 4), and a combination of indirect and direct methods (n = 3). The removal devices included an extraction balloon catheter (n = 7), basket catheter (n = 5), biopsy forceps (n = 3), and snare (n = 2). Stent removal using a DBE was feasible and useful as the first treatment for patients with bowel reconstruction. The choice of the direct and/or indirect method according to the situation of the migrated stent is important.

Circulating tumor DNA dynamics analysis in a xenograft mouse model with esophageal squamous cell carcinoma.

BACKGROUND: It remains unclear which factors, such as tumor volume and tumor invasion, influence circulating tumor DNA (ctDNA), and the origin of ctDNA in liquid biopsy is always problematic. To use liquid biopsies clinically, it will be very important to address these questions. AIM: To assess the origin of ctDNA, clarify the dynamics of ctDNA levels, assess ctDNA levels by using a xenograft mouse after treatment, and to determine whether tumor volume and invasion are related to ctDNA levels. METHODS: Tumor xenotransplants were established by inoculating BALB/c-nu/nu mice with the TE11 cell line. Groups of mice were injected with xenografts at two or four sites and sacrificed at the appropriate time point after xenotransplantation for ctDNA analysis. Analysis of ctDNA was performed by droplet digital PCR, using the human telomerase reverse transcriptase (hTERT) gene. RESULTS: Mice given two-site xenografts were sacrificed for ctDNA at week 4 and week 8. No hTERT was detected at week 4, but it was detected at week 8. However, in four-site xenograft mice, hTERT was detected both at week 4 and week 6. These experiments revealed that both tumor invasion and tumor volume were associated with the detection of ctDNA. In resection experiments, hTERT was detected at resection, but had decreased by 6 h, and was no longer detected 1 and 3 d after resection. CONCLUSION: We clarified the origin and dynamics of ctDNA, showing that tumor volume is an important factor. We also found that when the tumor was completely resected, ctDNA was absent after one or more days.

Plasma KRAS mutations predict the early recurrence after surgical resection of pancreatic cancer.

BACKGROUND: The technique to analyze circulating tumor DNA (ctDNA) in body fluid (so-called "liquid biopsy") is recently developed. AIMS: Our aim was to assess the utility of liquid biopsy for predicting progression of pancreatic ductal adenocarcinoma (PDAC) after surgical resection or chemotherapy. METHODS: A total of 72 patients with PDAC were retrospectively enrolled for this study, 33 treated surgically and 39 given chemotherapy, either FOLFIRINOX (oxaliplatin/irinotecan/fluorouracil/leucovorin) or gemcitabine plus nab-paclitaxel. Prior to treatment, patients were screened for the presence of KRAS mutations (G12D and G12V) in plasma using droplet digital polymerase chain reaction, and outcomes were compared. RESULTS: KRAS mutations were identified in plasma samples of 12 patients (36%) underwent surgical resection. Patients with plasma KRAS mutations had significantly shorter disease-free survival (DFS) and overall survival (p < .01 and p = .01, respectively). Of 10 clinical variables analyzed, plasma KRAS mutation was the factor predictive of DFS in multivariate analysis (RR = 3.58, 95% CI: 1.36-9.60; p = .01). Although 12 patients (31%) given chemotherapy tested positive for plasma KRAS mutations, there was no demonstrable relation between plasma KRAS mutations and progression-free survival (PFS) or overall survival (OS) (p = .35 and p = .68, respectively). CONCLUSIONS: In patients with PDAC, detection of KRAS mutations in plasma proved independently predictive of early recurrence after surgical resection but did not correlate with PFS following chemotherapy.

Heterogeneous distribution of Fusobacterium nucleatum in the progression of colorectal cancer.

BACKGROUND AND AIM: Fusobacterium nucleatum (Fn) is involved in colorectal cancer (CRC) growth and is a biomarker for patient prognosis and management. However, the ecology of Fn in CRC and the distribution of intratumoral Fn are unknown. METHODS: We evaluated Fn and the status of KRAS and BRAF in 200 colorectal neoplasms (118 adenomas and 82 cancers) and 149 matched adjacent normal mucosas. The differentiation status between "surface" and "deep" areas of cancer tissue and matched normal mucosa were analyzed in 46 surgical samples; the Ki-67 index was also evaluated in these samples. RESULTS: Fusobacterium nucleatum presence in the tumor increased according to pathological stage (5.9% [adenoma] to 81.8% [stage III/IV]), while Fn presence in normal mucosa also increased (7.6% [adenoma] to 40.9% [stage III/IV]). The detection rates of Fn on the tumor surface and in deep areas were 45.7% and 32.6%, while that of normal mucosa were 26.1% and 23.9%, respectively. Stage III/IV tumors showed high Fn surface area expression (66.7%). Fn intratumoral heterogeneity (34.8%) was higher than that of KRAS (4.3%; P < 0.001) and BRAF (2.2%; P < 0.001). The Ki-67 index in Fn-positive cases was higher than that in negative cases (93.9% vs 89.0%; P = 0.01). CONCLUSIONS: Fusobacterium nucleatum was strongly present in CRC superficial areas at stage III/IV. The presence of Fn in the deep areas of adjacent normal mucosa also increased. The intratumoral heterogeneity of Fn is important in the use of Fn as a biomarker, as Fn is associated with CRC proliferative capacity.

Prediction of the prognosis of advanced hepatocellular carcinoma by TERT promoter mutations in circulating tumor DNA.

BACKGROUND ANDAIM: Human telomerase reverse transcriptase (TERT) promoter mutations were the most prevalent mutations in patients with hepatocellular carcinoma (HCC). We tried to detect the mutations with plasma circulating tumor DNA (ctDNA) in patients with advanced HCC and elucidated their clinical utility. METHODS: Circulating tumor DNA in plasma was extracted from 130 patients with advanced HCC who were treated with systemic chemotherapy (n = 86) or transcatheter arterial chemoembolization (n = 44), and TERT promoter mutations were examined with digital droplet polymerase chain reaction. The correlations between these mutations and the clinical outcome of patients were analyzed. RESULTS: Of the 130 patients examined, 71 patients (54.6%) were positive for TERT promoter mutations in ctDNA, of which 64 patients were -124bp G > A and 10 were -146bp G > A. The presence of TERT promoter mutations was correlated with large intrahepatic tumor size (P = 0.05) and high des-gamma carboxyprothrombin (P = 0.005). Overall survival of the patients with the mutations was significantly shorter than those without them (P < 0.001), and the patients with high (≥ 1%) fractional abundance of the mutant alleles showed shorter survival than those with low (< 1%) fractional abundance. Multivariate analysis revealed that TERT promoter mutation (hazard ratio [HR]: 1.94; 95% confidence interval [CI], 1.18-3.24; P < 0.01), systemic chemotherapy (HR: 2.38; 95% CI, 1.29-4.57; P < 0.01), and vascular invasion (HR: 2.16; 95% CI, 1.22-3.76; P < 0.01) were significant factors for poor overall survival. CONCLUSIONS: TERT promoter mutations in ctDNA were associated with short survival and could be a valuable biomarker for predicting the prognosis of patients with advanced HCC.

Liquid biopsy for patients with IBD-associated neoplasia.

BACKGROUND: It is often difficult to diagnose inflammatory bowel disease (IBD)-associated neoplasia endoscopically due to background inflammation. In addition, due to the absence of sensitive tumor biomarkers, countermeasures against IBD-associated neoplasia are crucial. The purpose of this study is to develop a new diagnostic method through the application of liquid biopsy. METHODS: Ten patients with IBD-associated cancers and high-grade dysplasia (HGD) with preserved tumor tissue and blood were included. Tumor and non-tumor tissues were analyzed for 48 cancer-related genes using next-generation sequencing. Simultaneously, circulating tumor DNA (ctDNA) was analyzed for mutations in the target genes using digital PCR. RESULTS: Out of 10 patients, seven had IBD-related cancer and three had IBD-related HGD. Two patients had carcinoma in situ; moreover, three had stageII and two had stage III. To avoid false positives, the mutation rate cutoff was set at 5% based on the control results; seven of 10 (70%) tumor tissue samples were mutation-positive. Mutation frequencies for each gene were as follows: TP53 (20.9%; R136H), TP53 (25.0%; C110W), TP53 (8.5%; H140Q), TP53 (31.1%; R150W), TP53 (12.8%; R141H), KRAS (40.0%; G12V), and PIK3CA (34.1%; R 88Q). The same mutations were detected in the blood of these seven patients. However, no mutations were detected in the blood of the remaining three patients with no tumor tissue mutations. The concordance rate between tumor tissue DNA and blood ctDNA was 100%. CONCLUSION: Blood liquid biopsy has the potential to be a new method for non-invasive diagnosis of IBD-associated neoplasia.

Human Telomerase Reverse Transcriptase Gene Promoter Mutation in Serum of Patients with Hepatocellular Carcinoma.

BACKGROUND: Mutations in the human telomerase reverse transcriptase (hTERT) gene promoter have been reported in hepatocellular carcinoma (HCC); however, analyses of these mutations in liquid biopsies have been technically difficult because of the high GC content of the regions of interest within this promoter. We evaluated the feasibility and prognostic value of hTERT promoter mutations identified in circulating cell-free DNA (cfDNA) from the serum of patients with HCC. OBJECTIVE: A cohort of HCC patients (n = 36) who were curatively treated by surgical resection between June 2003 and September 2014 were enrolled in this study. METHODS: The presence of hTERT promoter mutations in cfDNA from the patients' serum was analyzed via modified droplet digital polymerase chain reaction, and associations were sought between specific promoter mutations and patients' disease-free survival (DFS). RESULTS: The G>A hTERT mutation at -124 bp was detected in the serum of 25 patients (69%). Although no marked differences were observed between the characteristics of the serum mutation-positive and serum mutation-negative patient groups, the DFS of patients with the mutation was significantly shorter than that of the serum mutation-negative patients (p = 0.02). Among 18 clinicopathologic and background liver factors examined, the presence of the -124 bp G>A mutation was an independent and significant predictor of patients' DFS (hazard ratio = 3.01, 95% confidence interval 1.11-10.5, p = 0.03) in multivariate analyses. CONCLUSIONS: The -124 bp G>A hTERT promoter mutation was observed in the serum of 69% of HCC patients who underwent surgical resection and was an independent predictor of disease progression in HCC.

Utility of liquid biopsy using urine in patients with pancreatic ductal adenocarcinoma.

In recent years, liquid biopsy for blood and body fluid in cancer patients has attracted attention. However, there have been few reports of liquid biopsy focusing on urine of pancreatic ductal adenocarcinoma (PDAC). In 56 patients with PDAC, DNA was extracted from urine and plasma prior to treatment, and KRAS mutations were analyzed with droplet digital PCR to examine the mutation detection rate. Our study showed that KRAS mutations were found in 27 cases (48%) in urine and 27 cases (48%) in plasma. The detection rate of urine KRAS mutations varied by renal functions. The rates were 70% (14/20) and 36% (13/36) in the creatinine clearance rate (CCr) < 70 mL/min group and in the CCr ≥ 70 mL/min group, respectively (P = .024). Whereas, no influence of the CCr was observed in the detection rates of plasma KRAS mutations. The rates were 50% (10/20) and 47% (17/36) in cases with the CCr < 70 mL/min group and the CCr ≥ 70 mL/min group, respectively. Although the sample size was small, this study clearly indicated a new possibility of less invasive urine liquid biopsy in PDAC patients.

A target-controlled infusion system with bispectral index monitoring of propofol sedation during endoscopic submucosal dissection.

BACKGROUND AND STUDY AIMS: Propofol administration via a target-controlled infusion system with bispectral index monitoring (BIS/TCI system) is expected to prevent complications from sedation during complex and long endoscopic procedures. We evaluated the feasibility of setting the BIS/TCI system for non-anesthesiologist administration of propofol (NAAP) during endoscopic submucosal dissection (ESD). PATIENTS AND METHODS: From May 2009 to February 2013, 250 patients with esophagogastric neoplasms were treated with ESD using the BIS/TCI system with NAAP. In the TCI system, the initial target blood concentration of propofol was set at 1.2 µg/mL. The titration speed of propofol was adjusted according to the BIS score and the movement of the patient. The BIS target level ranged from moderate to deep sedation, at which a stable BIS score between 60 and 80 was obtained. RESULTS: In 80.4 % of patients, it was possible to maintain stable sedation with a blood concentration of propofol of less than 1.6 µg/mL using TCI throughout the ESD procedure. The default setting for ideal blood concentration of propofol was 1.2 µg/mL, because the medians of the lower and upper bounds of blood concentration were 1.2 µg/mL (range 0.6 - 1.8 µg/mL) and 1.4 µg/mL (range 1.0 - 3.8 µg/mL), respectively. Although hypotension occurred in 27 patients (10.8 %), oxygen desaturation occurred in only nine patients (3.6 %), and severe desaturation in only two patients (0.8 %). CONCLUSIONS: Using our settings, it is possible for a non-anesthesiologist to maintain stable sedation during a lengthy endoscopic procedure through propofol sedation with a BIS/TCI system.

[A case of renal salt-wasting syndrome during chemotherapy for advanced gastric cancer].

A 66-year-old woman was admitted to our hospital with heartburn and liver dysfunction. She was diagnosed with advanced gastric cancer. After the initiation of chemotherapy with trastuzumab, capecitabine, and cisplatin, she developed hyponatremia and renal failure with renal salt-wasting syndrome (RSWS). She recovered from these conditions after infusion of hypertonic saline. A diagnosis of RSWS should be considered in patients with hyponatremia who receive cisplatin-based chemotherapy.