Sensitivity of endoscopic retrograde cholangiopancreatography standard cytology: 10-y review of the literature

Diagnostic Pearls and Pitfalls in the Evaluation of Small Biopsies From the Bile Duct and Ampulla

CONTEXT.—

Histopathologic evaluation of bile duct and ampullary biopsies can be challenging. Biopsies from these sites are often tiny, scant, and/or fragmented. When assessing these biopsies, there is significant overlap between reactive atypia and malignancy, in situ precursor lesions can be misinterpreted as malignancy, and nonprimary tumors can mimic primary disease.

OBJECTIVE.—

To provide diagnostic pearls and pitfalls in the evaluation of small biopsies from the biliary tract.

DATA SOURCES.—

Literature review of published studies and the author's own observations.

CONCLUSIONS.—

Because the procedures for obtaining specimens from the bile duct and ampulla are invasive, pathologists need to try to make definitive diagnoses. Diagnostic clues/pearls, ancillary studies, and recognition of various pitfalls can assist in providing accurate and confident diagnoses.

Artificial intelligence for automatic diagnosis and pleomorphic morphological characterization of malignant biliary strictures using digital cholangioscopy

Diagnosing and characterizing biliary strictures (BS) remains challenging. Artificial intelligence (AI) applied to digital single-operator cholangioscopy (D-SOC) holds promise for improving diagnostic accuracy in indeterminate BS. This multicenter study aimed to validate a convolutional neural network (CNN) model using a large dataset of D-SOC images to automatically detect and characterize malignant BS. D-SOC exams from three centers-Centro Hospitalar Universitário de São João, Porto, Portugal (n = 123), Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain (n = 18), and New York University Langone Hospital, New York, USA (n = 23)-were included. Frames were categorized based on histopathology. The CNN's performance in detecting tumor vessels, papillary projections, nodules, and masses was assessed. The dataset was split into 90% training and 10% validation sets. Performance metrics included AUC, sensitivity, specificity, PPV, and NPV. Analysis of 96,020 images from 164 D-SOC exams (50,427 malignant strictures and 45,593 benign findings) showed the CNN achieved 92.9% accuracy, 91.7% sensitivity, 94.4% specificity, 95.1% PPV, 93.1% NPV, and an AUROC of 0.95. Accuracy rates for morphological features were 90.8% (papillary projections), 93.6% (nodules), 93.2% (masses), and 78.1% (tumor vessels). AI-driven CNN models hold promise for enhancing diagnostic accuracy in suspected biliary malignancies. This multicenter study contributes diverse datasets to ongoing research, supporting further AI applications in this patient population.

Diagnostic Approach to Biliary Strictures

Biliary strictures represent a narrowing of the bile ducts, leading to obstruction that may result from benign or malignant etiologies. Accurate diagnosis is crucial but challenging due to overlapping features between benign and malignant strictures. This review presents a comprehensive diagnostic approach that integrates biochemical markers, imaging modalities, and advanced endoscopic techniques to distinguish between these causes. Imaging tools such as ultrasound, MRI/MRCP, and CECT are commonly used, each with distinct advantages and limitations. Furthermore, endoscopic procedures such as ERCP and EUS are key in tissue acquisition, enhancing diagnostic accuracy, especially for indeterminate or complex strictures. Recent innovations, including artificial intelligence and new endoscopic techniques, hold promise in enhancing precision and reducing diagnostic challenges. This review emphasizes a multidisciplinary strategy to improve diagnostic pathways, ensuring timely management for patients with biliary strictures.

Diagnostic cholangioscopy for surgical planning of extrahepatic cholangiocarcinoma

The recent clinical outcomes of multi-regimen chemotherapy included prolonged survival and a high rate of conversion to surgery in Asian patients with advanced biliary tract cancer. The ability of single-operator cholangioscopy (SOC) to detect and stage extrahepatic cholangiocarcinoma (CCC) in intraductal lesions is becoming more important in determining the extent of surgery. The aim of this study was to evaluate the role of SOC in surgical planning for extrahepatic CCC. We reviewed the consecutive data of patients who received nab-paclitaxel plus gemcitabine-cisplatin for the management of extrahepatic CCC and underwent preoperative evaluations between June 2020 and August 2022. SOC was performed to determine the precise extent of the disease in patients with a good response to chemotherapy who were considering surgical treatment. Among the 38 patients included, 30 (79%) were diagnosed with perihilar CCC, six (16%) with distal CCC, and two (5%) with intraductal papillary neoplasm of the bile duct. Intraductal evaluation with SOC altered disease extent defined by previous imaging findings in 14 (37%) patients. In those patients, five (36%) were changed to less extensive surgery, four (29%) to conversion surgery, four (29%) avoided surgery, and one (7%) was changed to more extensive surgery. Among the 38 included patients, 27 (71%) underwent surgery, and the accuracy of the visual impressions was 93%, as confirmed by the surgical pathology report. In conclusion, SOC examination of patients with potentially resectable extrahepatic CCC was more precise than conventional diagnostic evaluations and could help in planning surgical options.

Diagnostic Accuracy Performance of Fluorescence In Situ Hybridization (FISH) for Biliary Strictures: A Systematic Review and Meta-Analysis

Background and Aims: This systematic review and meta-analysis aims to compare the performance of UroVysion® FISH based on the different definitions of a positive result used in published literature with the goal of determining the optimal FISH definition for detecting pancreaticobiliary malignancy. Methods: A systematic literature search identified studies from database inception to Sept 2024 that evaluated the diagnostic performance of FISH in determining malignancy among patients with biliary strictures. All thresholds for positive FISH, as defined by the individual study, were included in this review. Subgroup analysis was performed based on the definitions of positive FISH as follows: (1) polysomy only; (2) polysomy, tetrasomy, or trisomy; and (3) polysomy or 9p deletion. Results: Eighteen studies comprising 2516 FISH specimens were analyzed, including 1133 (45.0%) with malignancy. Using a threshold for positivity as defined in individual studies, the overall sensitivity of FISH was 57.6% (95% confidence interval [CI], 49.4-65.4%), and the overall specificity was 87.8% (95% CI, 79.2-93.2%). Subgroup analysis showed that polysomy as the threshold for positive FISH yielded a sensitivity of 49.4% (95% CI, 43.2-55.5%), with an increased specificity of 96.2% (95% CI, 92.7-98.1%), while polysomy + tetrasomy/trisomy as positive FISH resulted in an increased sensitivity of 64.3% (95% CI 55.4-72.2%) but a decreased specificity of 78.9% (95% CI 64.4-88.5%). The addition of 9p deletion to polysomy as the criteria for a positive test resulted in a non-significant increase in sensitivity (54.7% (95% CI 42.4-66.5%) while maintaining specificity (95.1% (95% CI 84.0-98.6%). Conclusions: Based on these findings, polysomy only or polysomy/9p deletion should be considered as the criterion for defining a positive FISH test to improve diagnostic sensitivity while maintaining high specificity.

MicroRNAs as Bile-based biomarkers in pancreaticobiliary cancers (MIRABILE): a cohort study

BACKGROUND

Biliary obstruction can be due to both malignant and benign pancreaticobiliary disease. Currently, there are no biomarkers that can accurately help make this distinction. MicroRNAs (miRNAs) are stable molecules in tissue and biofluids that are commonly deregulated in cancer. The MIRABILE study aimed to identify miRNAs in bile that can differentiate malignant from benign pancreaticobiliary disease.

MATERIALS AND METHODS

There were 111 patients recruited prospectively at endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC) for obstructive jaundice, and bile was aspirated for cell-free RNA (cfRNA) extraction and analysis. In a discovery cohort of 78 patients (27 with pancreatic ductal adenocarcinoma (PDAC), 14 cholangiocarcinoma (CCA), 37 benign disease), cfRNA was subjected to small-RNA sequencing. LASSO regression was used to define bile miRNA signatures, and NormFinder to identify endogenous controls. In a second cohort of 87 patients (34 PDAC, 14 CCA, 39 benign disease), RT-qPCR was used for validation.

RESULTS

LASSO regression identified 14 differentially-expressed bile miRNAs of which 6 were selected for validation. When comparing malignant and benign pancreaticobiliary disease, bile miR-340 and miR-182 were validated and significantly differentially expressed ( P <0.05 and P <0.001, respectively). This generated an AUC of 0.79 (95% CI: 0.70-0.88, sensitivity 65%; specificity 82%) in predicting malignant disease.

CONCLUSION

Bile collected during biliary drainage contains miRNAs able to differentiate benign from malignant pancreaticobiliary diseases in patients with obstructive jaundice. These bile miRNAs have the potential to increase diagnostic accuracy.

Diagnostic Challenges in Follicular Cholangitis Mimicking Hilar Cholangiocarcinoma: A Case Report and Review of the Literature

Introduction: Distinguishing benign from malignant biliary strictures remains challenging despite diagnostic advancements. Follicular cholangitis, a rare benign condition, presents with symptoms and imaging similar to malignancies like cholangiocarcinoma, often complicating diagnosis, particularly when tumor markers are elevated and imaging suggests metastasis. Case presentation: A 57-year-old woman with hypertension and diabetes was admitted with jaundice. Elevated bilirubin and liver enzymes alongside high carbohydrate antigen 19-9 (CA19-9) levels but normal carcinoembryonic antigen (CEA) were noted. Imaging showed thickening from the hilar duct to the proximal common bile duct, accompanied by suspected lymph node metastases. Comprehensive ERCP-guided biopsies found no malignancy. Surgical resection led to a diagnosis of follicular cholangitis. Conclusions: Follicular cholangitis' long-term prognosis is elusive due to its rarity, and preoperative diagnosis is challenging. Increased awareness may improve diagnostic and treatment approaches, as this case adds to the disease's understanding.

Duodenal Fluid Analysis as a Rewarding Approach to Detect Low-Abundance Mutations in Biliopancreatic Cancers

Diagnosis of biliopancreatic cancers by the available serum tumor markers, imaging, and histopathological tissue specimen examination remains a challenge. Circulating cell-free DNA derived from matched pairs of secretin-stimulated duodenal fluid (DF) and plasma from 10 patients with biliopancreatic diseases and 8 control subjects was analyzed using AmpliSeq™ HD technology for Ion Torrent Next-Generation Sequencing to evaluate the potential of liquid biopsy with DF in biliopancreatic cancers. The median cfDNA concentration was greater in DF-derived than in plasma-derived samples. A total of 13 variants were detected: 11 vs. 1 were exclusive for DF relative to the plasma source, and 1 was shared between the two body fluids. According to the four-tier systems, 10 clinical tier-I-II (76.9%), 1 tier-III (7.7%), and 2 tier-IV (15.4%) variants were identified. Notably, the 11 tier-I-III variants were exclusively found in DF-derived cfDNA from five patients with biliopancreatic cancers, and were detected in seven genes (KRAS, TP53, BRAF, CDKN2A, RNF43, GNAS, and PIK3CA); 82% of the tier-I-III variants had a low abundance, with a VAF < 6%. The mutational profiling of DF seems to be a reliable and promising tool for identifying cancer-associated alterations in malignant cancers of the biliopancreatic tract.

Impact of a new dedicated sheath device for tissue sampling of biliary stricture on pathological diagnostic yield: Retrospective study

Background and study aims Endoscopic transpapillary biliary forceps biopsy (TBFB) is a common method for obtaining specimens from biliary lesions. Its diagnostic yield is unsatisfactory; to overcome this disadvantage, a dedicated sheath has been developed. This study aimed to evaluate the outcomes of conventional TBFB and TBFB with a novel sheath device. Patients and methods Consecutive patients who underwent TBFB between January 2020 and December 2021 were retrospectively evaluated. The rate of obtaining adequate samples, failed attempts at forceps insertion into the bile duct, and sensitivity were compared between the two groups. Results Ninety-two patients who underwent 115 endoscopic retrograde cholangiopancreatographies (76 in the conventional group vs. 39 in the dedicated sheath group) were included. The rates of obtaining adequate samples, failed attempts of the forceps into the bile duct, and sensitivity were 72.4% vs. 89.7% ( P = 0.03), 28.3% vs. 0% ( P < 0.01), and 66.7% vs. 88.9% ( P = 0.02), respectively. Conclusions TBFB with the novel sheath device contributed to improved sensitivity for diagnosis of biliary stricture without insertion of forceps outside the bile duct.

Combining brushing cytology with simultaneous vacuum aspiration in suspicious biliopancreatic malignancies: A multicenter propensity score-matched study (with video)

BACKGROUND

Brush cytology during endoscopic retrograde cholangiopancreatography (ERCP) is a standard approach in diagnosing biliopancreatic strictures, with yet unsatisfying sensitivity.

AIMS

We brought additional simultaneous vacuum aspiration to brushing process and re-evaluate the diagnostic performance.

METHODS

This multi-centered retrospective study was conducted in three tertiary centers. Consecutive patients with biliopancreatic strictures were identified. The patients were divided into two arms: the conventional arm (CA) receiving general brushing approach, and the modified arm (MA) being treated with additional vacuum aspiration when performing bushing. The 1:1 propensity-score matching was implemented to tackle the selective biases.

RESULTS

A total of 555 patients were identified and 200 patient pairs (193 males, 207 females, with a mean age of 68.1 ± 13.1 years.) fell into the ultimate evaluation. A final diagnosis of malignant stricture was established in 243 patients. The diagnostic yield of the MA group was substantially better than that of the CA group, whether "suspicious malignancies" were considered malignancies or not. The rates of sensitivity, specificity and accuracy were 46.2%, 100%, 68.0% in the MA group, and 15.3%, 98.7%, and 47.0% in the CA group respectively.

CONCLUSIONS

Brushing accompanied by simultaneous vacuum aspiration at ERCP improves the diagnostic yield in suspicious biliopancreatic malignancies.

National guidelines for the diagnosis and treatment of hilar cholangiocarcinoma

A consensus meeting of national experts from all major national hepatobiliary centres in the country was held on May 26, 2023, at the Pakistan Kidney and Liver Institute & Research Centre (PKLI & RC) after initial consultations with the experts. The Pakistan Society for the Study of Liver Diseases (PSSLD) and PKLI & RC jointly organised this meeting. This effort was based on a comprehensive literature review to establish national practice guidelines for hilar cholangiocarcinoma (hCCA). The consensus was that hCCA is a complex disease and requires a multidisciplinary team approach to best manage these patients. This coordinated effort can minimise delays and give patients a chance for curative treatment and effective palliation. The diagnostic and staging workup includes high-quality computed tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography. Brush cytology or biopsy utilizing endoscopic retrograde cholangiopancreatography is a mainstay for diagnosis. However, histopathologic confirmation is not always required before resection. Endoscopic ultrasound with fine needle aspiration of regional lymph nodes and positron emission tomography scan are valuable adjuncts for staging. The only curative treatment is the surgical resection of the biliary tree based on the Bismuth-Corlette classification. Selected patients with unresectable hCCA can be considered for liver transplantation. Adjuvant chemotherapy should be offered to patients with a high risk of recurrence. The use of preoperative biliary drainage and the need for portal vein embolisation should be based on local multidisciplinary discussions. Patients with acute cholangitis can be drained with endoscopic or percutaneous biliary drainage. Palliative chemotherapy with cisplatin and gemcitabine has shown improved survival in patients with irresectable and recurrent hCCA.

American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: summary and recommendations

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for the diagnosis of malignancy in patients with biliary strictures of undetermined etiology. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework and addresses the role of fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS in the diagnosis of malignancy in patients with biliary strictures. In the endoscopic workup of these patients, we suggest the use of fluoroscopic-guided biopsy sampling in addition to brush cytology over brush cytology alone, especially for hilar strictures. We suggest the use of cholangioscopic and EUS-guided biopsy sampling especially for patients who undergo nondiagnostic sampling, cholangioscopic biopsy sampling for nondistal strictures and EUS-guided biopsy sampling distal strictures or those with suspected spread to surrounding lymph nodes and other structures.

American Society for Gastrointestinal Endoscopy guideline on role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: methodology and review of evidence

Biliary strictures of undetermined etiology pose a diagnostic challenge for endoscopists. Despite advances in technology, diagnosing malignancy in biliary strictures often requires multiple procedures. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rigorously review and synthesize the available literature on strategies used to diagnose undetermined biliary strictures. Using a systematic review and meta-analysis of each diagnostic modality, including fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS-guided FNA or fine-needle biopsy sampling, the American Society for Gastrointestinal Endoscopy Standards of Practice Committee provides this guideline on modalities used to diagnose biliary strictures of undetermined etiology. This document summarizes the methods used in the GRADE analysis to make recommendations, whereas the accompanying article subtitled "Summary and Recommendations" contains a concise summary of our findings and final recommendations.

Deep Learning for Automatic Diagnosis and Morphologic Characterization of Malignant Biliary Strictures Using Digital Cholangioscopy: A Multicentric Study

Digital single-operator cholangioscopy (D-SOC) has enhanced the ability to diagnose indeterminate biliary strictures (BSs). Pilot studies using artificial intelligence (AI) models in D-SOC demonstrated promising results. Our group aimed to develop a convolutional neural network (CNN) for the identification and morphological characterization of malignant BSs in D-SOC. A total of 84,994 images from 129 D-SOC exams in two centers (Portugal and Spain) were used for developing the CNN. Each image was categorized as either a normal/benign finding or as malignant lesion (the latter dependent on histopathological results). Additionally, the CNN was evaluated for the detection of morphologic features, including tumor vessels and papillary projections. The complete dataset was divided into training and validation datasets. The model was evaluated through its sensitivity, specificity, positive and negative predictive values, accuracy and area under the receiver-operating characteristic and precision-recall curves (AUROC and AUPRC, respectively). The model achieved a 82.9% overall accuracy, 83.5% sensitivity and 82.4% specificity, with an AUROC and AUPRC of 0.92 and 0.93, respectively. The developed CNN successfully distinguished benign findings from malignant BSs. The development and application of AI tools to D-SOC has the potential to significantly augment the diagnostic yield of this exam for identifying malignant strictures.

A Unique Approach to Obtaining Tissue in a Difficult to Access Indeterminate Biliary Stricture: Percutaneous Cholangioscopy and Biopsy

When evaluating biliary strictures, establishing a diagnosis can present challenges. The first-line approach of endoscopic retrograde cholangiopancreatography can often involve anatomic restrictions. Traditionally, percutaneous transhepatic cholangioscopy has been the answer for biopsies unable to be obtained with the modalities above but requires time for large tract dilation and days of sinus tract maturation to allow for a scope. We present a novel case of percutaneous digital cholangioscopy with SpyGlass DS, a small caliber scope traditionally used with endoscopic retrograde cholangiopancreatography, used for percutaneous transhepatic cholangioscopy after previous failed attempts by several different standard methods. Our case highlights a multidisciplinary approach in ultimately diagnosing malignancy.

Advances in pre-treatment evaluation of pancreatic ductal adenocarcinoma: a narrative review

BACKGROUND AND OBJECTIVE

Despite advances in the multidisciplinary management of pancreatic cancer, overall prognosis remains poor, due to early progression of the disease. There is a need to also take action in staging, to make it increasingly accurate and complete, to define the setting of the therapeutic strategy. This review was planned to update the current status of pre-treatment evaluation for pancreatic cancer.

METHODS

We conducted an extensive review, including relevant articles dealing with traditional imaging, functional imaging and minimally invasive surgical procedures before treatment for pancreatic cancer. We searched articles written in English only. Data in the PubMed database, published in the period between January 2000 and January 2022, were retrieved. Prospective observational studies, retrospective analyses and meta-analyses were reviewed and analysed.

KEY CONTENT AND FINDINGS

Each imaging modality (endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography, computed tomography, positron emission tomography/computed tomography, staging laparoscopy) has its own diagnostic advantages and limitations. The sensitivity, specificity and accuracy for each image set are reported. Data that support the increasing role of neoadjuvant therapy (radiotherapy and chemotherapy) and the meaning of a patient-tailored treatment selection, based on tumour staging, are also discussed.

CONCLUSIONS

A multimodal pre-treatment workup should be searched as it improves staging accuracy, orienting patients with resectable tumors towards surgery, optimizing patient selection with locally advanced tumors to neoadjuvant or definite therapy and avoiding surgical resection or curative radiotherapy in those with metastatic disease.

ACG Clinical Guideline: Diagnosis and Management of Biliary Strictures

A biliary stricture is an abnormal narrowing in the ductal drainage system of the liver that can result in clinically and physiologically relevant obstruction to the flow of bile. The most common and ominous etiology is malignancy, underscoring the importance of a high index of suspicion in the evaluation of this condition. The goals of care in patients with a biliary stricture are confirming or excluding malignancy (diagnosis) and reestablishing flow of bile to the duodenum (drainage); the approach to diagnosis and drainage varies according to anatomic location (extrahepatic vs perihilar). For extrahepatic strictures, endoscopic ultrasound-guided tissue acquisition is highly accurate and has become the diagnostic mainstay. In contrast, the diagnosis of perihilar strictures remains a challenge. Similarly, the drainage of extrahepatic strictures tends to be more straightforward and safer and less controversial than that of perihilar strictures. Recent evidence has provided some clarity in multiple important areas pertaining to biliary strictures, whereas several remaining controversies require additional research. The goal of this guideline is to provide practicing clinicians with the most evidence-based guidance on the approach to patients with extrahepatic and perihilar strictures, focusing on diagnosis and drainage.

Comparison of two intraductal brush cytology devices for suspected malignant biliary strictures: randomized controlled trial

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) with biliary brush cytology is commonly used to diagnose malignant pancreatobiliary strictures. This trial compared the sensitivity of two intraductal brush cytology devices.

METHODS

A randomized controlled trial in which consecutive patients with suspected malignant, extrahepatic biliary strictures were randomized (1:1) to a dense or conventional brush cytology device. Primary endpoint was sensitivity. Interim analysis was conducted after 50% of the patients completed follow-up. Results were interpreted by a data safety monitoring board.

RESULTS

Between June 2016 and June 2021, 64 patients were randomized to the dense (27 patients, 42%) or conventional brush (37 patients, 58%). Malignancy was diagnosed in 60 patients (94%) and benign disease in 4 patients (6%). Diagnoses were confirmed by histopathology in 34 patients (53%), cytopathology in 24 patients (38%), and clinical or radiological follow up in 6 patients (9%). Sensitivity of the dense brush was 50%, compared to 44% for the conventional brush (p = 0·785).

DISCUSSION

The results of this randomized controlled trial showed that the sensitivity of a dense brush is not superior to a conventional brush for diagnosing malignant extrahepatic pancreatobiliary strictures. This trial was prematurely ended for reasons of futility.

TRIAL REGISTRATION

Netherlands Trial Register number; NTR5458.

Genetic Analyses of Cell-Free DNA in Pancreatic Juice or Bile for Diagnosing Pancreatic Duct and Biliary Tract Strictures

Poor prognosis of pancreaticobiliary malignancies is attributed to intrinsic biological aggressiveness and the lack of reliable methods for early diagnosis. This study aimed to evaluate the feasibility and availability of pancreatic juice- and bile-derived cell-free DNA (cfDNA) for diagnosing pancreaticobiliary strictures. From October 2020 to February 2022, pancreatic juice or bile was obtained from 50 patients with pancreaticobiliary strictures during endoscopic retrograde cholangiopancreatography. cfDNAs extracted from the samples were analyzed using next-generation sequencing and a cancer gene panel. The obtained cfDNAs, genetic data and clinical information were analyzed for diagnosis. cfDNA concentrations in pancreatic juice were higher in the intraductal papillary mucinous neoplasm group than in the other groups, whereas those in bile were similar in all groups. In pancreatic juice, the sensitivity, specificity and positive and negative predictive values of cfDNA analyses were 33%, 100%, 100% and 71.4%, respectively, whereas those of cytological analyses were 0%, 100%, 0% and 62.5%, respectively. In bile, those of cell-free DNA analyses were 53%, 75%, 89.5% and 28.6%, respectively, whereas those of cytological analyses were 19%, 100%, 100% and 16%, respectively. In conclusion, pancreatic juice- and bile-derived cfDNA is a novel liquid biopsy tool that can diagnose pancreaticobiliary strictures.

Pronounced squamous cell contamination in biliary tract cytology: A diagnostic pitfall

Squamous cells are rarely found in biliary tract cytology specimens, and when present are typically scant in quantity. Over an 8-year time period, two cases at our institution reporting abundant squamous cells were identified. Both patients underwent endoscopic retrograde cholangiopancreatography with bile duct brushings and removal of a migrated biliary stent. The migrated stents were retrieved using rat toothed forceps and required removal of the endoscope through the esophagus with the stent exposed to esophageal and oral mucosa outside of the endoscope. Cytologic examination of the accompanying biliary stent material accordingly revealed abundant benign squamous cells. However, bile duct brushings showed benign ductal epithelial cells without squamous cells. Prior and subsequent cytology and bile duct surgical pathology specimens did not show squamous metaplasia. Migrated biliary stents that require endoscopic withdrawal increase the risk of contaminating samples with squamous cells. Recognition of this unique scenario is important, as the differential diagnosis includes squamous metaplasia and squamous neoplasia.

The Role of Fluorescence In Situ Hybridization in Pancreatobiliary Brushing Cytology: A Large Retrospective Review with Histologic Correlation

(1) Background: Although the specificity of brush cytology for the detection of malignant pancreaticobiliary strictures is high, its sensitivity is low. Fluorescence in situ hybridization (FISH) can be used to detect chromosomal aneuploidy in biliary brushing specimens, and when used as an adjunct to routine cytology, it significantly improves diagnostic sensitivity. (2) Methods: We searched our laboratory information system to identify all bile duct brush cytology cases with follow-up surgical pathology between January 2001 and September 2019. Cytologic diagnoses were classified as negative, atypical, suspicious, or malignant. Correlated surgical pathological diagnoses were classified as benign or malignant. FISH test results were obtained for a subset of cytology cases with concurrent FISH testing, and the sensitivity, specificity, positive predictive value, and negative predictive value in identifying malignancy for cytology alone, FISH alone, and combined cytology and FISH were calculated. (3) Results: A total of 1017 brushing cytology cases with histologic correlation were identified. A total of 193 FISH tests were performed concurrently with cytological specimens. Malignant diagnoses were identified in 623 of 1017 patients, while 394 patients had benign strictures. The sensitivity, specificity, positive predictive, and negative predictive rate were 65%, 78%, 83%, and 49% for cytology alone; 72%, 67%, 63%, and 68% for FISH alone; and 85%, 42%, 60%, and 74% for combined cytology and FISH, respectively. Among FISH-positive cases, the risk of malignancy for polysomy was 82% and 32% for trisomy. (4) Conclusions: FISH improves the sensitivity and negative predictive rate of bile duct brush cytology. The combination of cytology and FISH has increased the sensitivity from 65% to 85% and the negative predictive rate from 49% to 74% when compared to cytology alone. A patient with a polysomy FISH result had a significantly higher risk of malignancy than a patient with a trisomy 7 result (82% vs. 32%, p < 0.00001).

Observation for the feasibility of a bile duct biopsy technique using a loop-tip guidewire during endoscopic retrograde cholangiopancreatography

Endoscopists frequently have difficulty approaching biliary lesions using biopsy forceps. The aim of this study was not only to describe an easy technique for biliary biopsy assisted by a looped guidewire but also to present preliminary results regarding its safety and feasibility. A preliminary proof-of-concept study was performed at a single tertiary medical center. Between August 2019 and January 2020, 13 patients with bile duct strictures underwent endoscopic retrograde cholangiopancreatography (ERCP) with a new loop guidewire-assisted forceps approach technique. The efficacy and safety were evaluated using the success rate as the primary outcome and diagnostic yield and complication rates as secondary outcomes. The tissue sampling success rate was 100% (13/13). All samples were acceptable for histopathological analysis. Eleven specimens were confirmed to be adenocarcinomas. After reexamination of the remaining 2 patients, all cases were eventually diagnosed as being malignant. The sensitivity of the single procedure was 84.6% (11/13). There were 2 patients with mild hyperamylasemia, but there were no severe complications with respect to safety. This new technique could enhance the success rate and diagnostic yield and reduce the risk of failure when using the biopsy forceps approach during ERCP.

Use of Endoscopic Scraper and Cell Block Technique as a Replacement for Conventional Brush for Diagnosing Malignant Biliary Strictures

Histological evidence is essential for diagnosing malignant biliary strictures. However, conventional brush cytology remains the primary method used worldwide, despite its low diagnostic sensitivity and accuracy, as it is technically easy, rapid, and cost-effective. The aim of this study was to evaluate the diagnostic performance of a recently introduced endoscopic scraper, the simplicity of which is comparable to that of a conventional brush, by comparing diagnostic yields and the number of collected cells. The sensitivity of the endoscopic scraper when using the cell block technique was significantly higher than when using brush cytology or a brush with the cell block technique (53.6% vs. 30.9%, p < 0.001; 53.6% vs. 31.6%, p = 0.024, respectively). Quantitative digital image analysis of cell block sections revealed that the median number of cells obtained with the endoscopic scraper was significantly higher than when using the brush (1917 vs. 1014 cells, p = 0.042). Furthermore, seven cases (8.3%; 7/84) were diagnosed by immunohistochemical analysis of the cell block section obtained from the endoscopic scraper. Given its simplicity and greater capacity for sample acquisition, use of the endoscopic scraper in conjunction with the cell block technique could replace brush cytology for the histological diagnosis of malignant biliary strictures.

Next-generation sequencing of bile cell-free DNA for the early detection of patients with malignant biliary strictures

OBJECTIVE

Despite significant progresses in imaging and pathological evaluation, early differentiation between benign and malignant biliary strictures remains challenging. Endoscopic retrograde cholangiopancreatography (ERCP) is used to investigate biliary strictures, enabling the collection of bile. We tested the diagnostic potential of next-generation sequencing (NGS) mutational analysis of bile cell-free DNA (cfDNA).

DESIGN

A prospective cohort of patients with suspicious biliary strictures (n=68) was studied. The performance of initial pathological diagnosis was compared with that of the mutational analysis of bile cfDNA collected at the time of first ERCP using an NGS panel open to clinical laboratory implementation, the Oncomine Pan-Cancer Cell-Free assay.

RESULTS

An initial pathological diagnosis classified these strictures as of benign (n=26), indeterminate (n=9) or malignant (n=33) origin. Sensitivity and specificity of this diagnosis were 60% and 100%, respectively, as on follow-up 14 of the 26 and eight of the nine initially benign or indeterminate strictures resulted malignant. Sensitivity and specificity for malignancy of our NGS assay, herein named Bilemut, were 96.4% and 69.2%, respectively. Importantly, one of the four Bilemut false positives developed pancreatic cancer after extended follow-up. Remarkably, the sensitivity for malignancy of Bilemut was 100% in patients with an initial diagnosis of benign or indeterminate strictures. Analysis of 30 paired bile and tissue samples also demonstrated the superior performance of Bilemut.

CONCLUSION

Implementation of Bilemut at the initial diagnostic stage for biliary strictures can significantly improve detection of malignancy, reduce delays in the clinical management of patients and assist in selecting patients for targeted therapies.

Peroral cholangioscopy: Update on the state-of-the-art

Peroral cholangioscopy (POC) is an endoscopic procedure that allows direct intraductal visualization of the biliary tract. POC has emerged as a vital tool for indeterminate biliary stricture evaluation and treatment of difficult biliary stones. Over several generations of devices, POC has fulfilled additional clinical needs where other diagnostic or therapeutic modalities have been inadequate. With adverse event rates comparable to standard endoscopic retrograde cholangioscopy and unique technical attributes, the role of POC is likely to continue expand. In this frontiers article, we highlight the existing and growing clinical applications of POC as well as areas of ongoing research.

Analysis of MicroRNA in Bile Cytologic Samples Is Useful for Detection and Diagnosis of Extrahepatic Cholangiocarcinoma

OBJECTIVES

This study aimed to develop reliable biomarkers that improve the ability of bile cytology to diagnose cholangiocarcinoma vs benign biliary lesions.

METHODS

Many studies indicate that microRNAs (miRNAs) are potential candidates for the early diagnosis of cancer. We analyzed the expression of five tumor-associated miRNAs (miR-31-5p, miR-122-5p, miR-378d, miR-182-5p, and miR-92a-3p) in cytology samples using quantitative reverse transcription polymerase chain reaction. We collected 52 surgically resected tissue samples, 84 cytologic specimens from smears (53 cases of cancer and 31 cases of noncancer), and 40 residual sediments after smearing for routine cytology at Hiroshima University Hospital.

RESULTS

The expression of miR-31-5p, miR-378d, and miR-122-5p was significantly higher in cancer tissues than those in normal tissues, while miR-182-5p expression was lower. The expression of miR-31-5p, miR-378d, miR-182-5p, and miR-92a-3p was significantly higher in detached cell samples from smears of cholangiocarcinoma cases than in those from noncancer cases.

CONCLUSIONS

These results suggest that the analysis of miRNAs in bile cytologic specimens is a promising auxiliary tool for distinguishing cholangiocarcinoma from benign biliary lesions.

Artificial intelligence for automatic diagnosis of biliary stricture malignancy status in single-operator cholangioscopy: a pilot study

BACKGROUND AND AIMS

The diagnosis and characterization of biliary strictures (BSs) is challenging. The introduction of digital single-operator cholangioscopy (DSOC) that allows direct visual inspection of the lesion and targeted biopsy sampling significantly improved the diagnostic yield in patients with indeterminate BSs. However, the diagnostic efficiency of DSOC remains suboptimal. Convolutional neural networks (CNNs) have shown great potential for the interpretation of medical images. We aimed to develop a CNN-based system for automatic detection of malignant BSs in DSOC images.

METHODS

We developed, trained, and validated a CNN-based on DSOC images. Each frame was labeled as a normal/benign finding or as a malignant lesion if histopathologic evidence of biliary malignancy was available. The entire dataset was split for 5-fold cross-validation. In addition, the image dataset was split for constitution of training and validation datasets. The performance of the CNN was measured by calculating the area under the receiving operating characteristic curve (AUC), sensitivity, specificity, and positive and negative predictive values.

RESULTS

A total of 11,855 images from 85 patients were included (9695 malignant strictures and 2160 benign findings). The model had an overall accuracy of 94.9%, sensitivity of 94.7%, specificity of 92.1%, and AUC of .988 in cross-validation analysis. The image processing speed of the CNN was 7 ms per frame.

CONCLUSIONS

The developed deep learning algorithm accurately detected and differentiated malignant strictures from benign biliary conditions. The introduction of artificial intelligence algorithms to DSOC systems may significantly increase its diagnostic yield for malignant strictures.

Biliary Tree Diagnostics: Advances in Endoscopic Imaging and Tissue Sampling

The diagnostic approach to the biliary tree disorders can be challenging, especially for biliary strictures. Albeit the great diagnostic impact of endoscopic retrograde cholangiopancreatography (ERCP) which allows one to obtain fluoroscopic imaging and tissue sampling through brush cytology and/or forceps biopsy, a considerable proportion of cases remain indeterminate, leading to the risk of under/over treated patients. In the last two decades, several endoscopic techniques have been introduced in clinical practice, shrinking cases of uncertainties and improving diagnostic accuracy. The aim of this review is to discuss recent advances and emerging technologies applied to the management of biliary tree disorders through peroral endoscopy procedures.

Choledochoscopy: An update

Choledochoscopy, or cholangioscopy, is an endoscopic procedure for direct visualization within the biliary tract for diagnostic or therapeutic purposes. Since its conception in 1879, many variations and improvements are made to ensure relevance in diagnosing and managing a range of intrahepatic and extrahepatic biliary pathologies. This ranges from improved visual impression and optical guided biopsies of indeterminate biliary strictures and clinically indistinguishable pathologies to therapeutic uses in stone fragmentation and other ablative therapies. Furthermore, with the evolving understanding of biliary disorders, there are significant innovative ideas and techniques to fill this void, such as nuanced instances of biliary stenting and retrieving migrated ductal stents. With this in mind, we present a review of the current advancements in choledo-choscopy with new supporting evidence that further delineates the role of choledochoscopy in various diagnostic and therapeutic interventions, complications, limitations and put forth areas for further study.

Efficacy of endoscopic samplings during initial biliary drainage for cases of pancreatic head cancer: United diagnostic yields of multiple pathological samplings

BACKGROUND/OBJECTIVES

The diagnostic ability of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been fully studied; however, the efficacy of other endoscopic samplings (OESs) is less clear. The aim of this study was to examine the diagnostic efficacies of OESs for pancreatic head cancer (PHC).

METHODS

The diagnostic efficacies of endoscopic samplings were retrospectively analyzed in 448 PHC cases and 63 cases of mass-forming pancreatitis (MFP) during initial transpapillary biliary drainage. The OESs included duodenal biopsy (118 PHCs and 50 MFPs), biliary biopsy (218 and 51) with cytology (368 and 53), and pancreatic duct biopsy (23 and 13) with cytology (56 and 43). EUS-FNA was conducted in a different session (149 and 62). Factors associated with OES sensitivity were analyzed. The sensitivity of biliary biopsy was compared between 1.95 mm and 1.8 mm forceps.

RESULTS

Cancer cells were confirmed in 87.9% of the EUS-FNA samplings and in 64.1% (268/418) obtained by combined OESs (average 1.7 OES types per case): 68.6% by duodenal biopsy, 59.6% by biliary biopsy, 32.6% by biliary cytology, 73.9% by pancreatic duct biopsy, and 33.9% by pancreatic duct cytology. No MFP cases revealed cancer by any sampling. OESs did not increase adverse events. Duodenal stenosis, serum bilirubin, tumor size, and pancreatic juice amounts were associated with OES sensitivity. Biliary biopsy had the same sensitivity with different forceps.

CONCLUSION

EUS-FNA was the most diagnostic protocol; however, OESs can be safely applied during the initial biliary drainage to reduce the demand for EUS-FNA while providing good diagnostic yields.

Biliary Strictures: A Surgeon's Perspective for Interventional Radiologists

Biliary strictures can be a challenging clinical problem to manage and often have unclear etiologies, including benign and malignant causes. Left untreated, these problems can lead to significant morbidity and mortality linked to their underlying diagnosis. The approach to adult patients with biliary strictures requires a multidisciplinary team involving surgeons, interventional endoscopists, and interventional radiologists for diagnosis, symptom relief, palliation, as well as potential curative management. From a surgeon's perspective, there are many ways to classify and approach these strictures. It is of paramount importance to start with an excellent understanding of the patient's prior surgical history. In approaching a patient with a new diagnosis of biliary stricture, it is also critical to understand its etiology relatively quickly, as 70% are malignant in the adult population. Concurrently, one must clearly define the location and extent of the stricture: intrahepatic, hilar, or distal extrahepatic bile duct, as well as whether it is a singular lesion or multifocal phenotypes. This information provides a path forward in clinical decision-making regarding durability and efficacy of therapy, which is typically aimed at decompression and/or surgical resection to prevent cholangitis, sepsis, and progressive hepatic insufficiency.

The Status and Development of Oral Choledochoscopy Diagnosis and Treatment of Biliary Tract Diseases

Choledochoscopy technology has realized the direct observation of bile duct lesions, and can be loaded with a variety of special accessories to perform the corresponding diagnosis and treatment operations, and has become an important means for the diagnosis of unexplained bile duct stricture and treatment of refractory bile duct stones. With the further enhancement of the imaging quality and operability, the clinical application of choledochoscopy has gradually expanded to the precise positioning of cholangiocarcinoma before surgical resection, the drainage of the gallbladder through the nipple, the removal of the displaced bile duct stent and other fields. This paper briefly reviewed the historical evolution of choledochoscopy and reviewed the latest clinical advances of oral choledochoscopy in the diagnosis and treatment of biliary tract diseases.

Fluoroscopy-guided shaped endobiliary biopsy at endoscopic retrograde cholangiography can accurately diagnose biliary neoplasia: Results from a large cohort

Background and study aims  The sensitivity of using standard endobiliary forceps biopsy to diagnose neoplastic biliary lesions remains low. We have developed a unique biopsy approach, termed fluoroscopy-guided, shaped endobiliary biopsy (FSEB), in which the biopsy forceps are modified to improve diagnostic yield. In this study, we evaluate the diagnostic characteristics of FSEB for endobiliary lesions at endoscopic retrograde cholangiography (ERC). Patients and methods  Consecutive patients undergoing FSEB between 1/2001 and 12/2014 were retrospectively enrolled. The identification of neoplastic lesions with FSEB, was the primary endpoint. The gold standard of neoplasia was histopathology, cytology or surgical histopathology. The benign cases were followed up for one year. Results  A total of 204 patients undergoing 250 biopsy sessions by FSEB were analyzed. Per-patient analysis was performed and FSEB showed 81.1 % sensitivity and 88.2 % accuracy. FSEB detection of proximal biliary lesions was more sensitive (91.1 % vs 73.2 %, P  < 0.01) and accurate (94.9 % vs 82.2 %, P  < 0.01) compared to distal lesions. No complications from FSEB were reported. Conclusions  FSEB shows high accuracy for diagnosis of neoplasia in biliary strictures, especially for proximal lesions. Future prospective randomized controlled studies are merited to further validate the role of FSEB as the first-line sampling tool for evaluation of biliary neoplasm.

Diagnosing Biliary Strictures: Distinguishing IgG4-Related Sclerosing Cholangitis From Cholangiocarcinoma and Primary Sclerosing Cholangitis

Biliary strictures caused by inflammation or fibrosis lead to jaundice and cholangitis which often make it difficult to distinguish malignant strictures. In cases when malignancy cannot be excluded, surgery is often performed. The concept of immunoglobulin G4 (IgG4)-related sclerosing cholangitis (SC) as a benign biliary stricture was recently proposed. The high prevalence of the disease in Asian countries has resulted in multiple diagnostic and treatment guidelines; however, there is need to formulate a standardized diagnostic strategy among various countries considering the utility, invasiveness, and cost-effectiveness. We evaluated accuracies of various diagnostic modalities for biliary strictures comparing pathology in the Delphi meetings which were held in Rochester, MN. The diagnostic utility for each modality was graded according to the experts, including gastroenterologists, endoscopists, radiologists, and pathologists from the United States and Japan. Diagnostic utility of 10 modalities, including serum IgG4 level, noninvasive imaging, endoscopic ultrasound, endoscopic retrograde cholangiopancreatography-related diagnostic procedures were advocated and the reasons were specified. Serum IgG4 level, noninvasive imaging, diagnostic endoscopic ultrasound and intraductal ultrasonography under endoscopic retrograde cholangiopancreatography were recognized as useful modalities for the diagnosis. The information in this article will aid in the diagnosis of biliary strictures particularly for distinguishing IgG4-SC from cholangiocarcinoma and/or primary SC.

Endoscopic Evaluation of Biliary Strictures: Current and Emerging Techniques

The diagnosis of biliary strictures in clinical practice can be challenging. Discriminating between benign and malignant biliary strictures is important to prevent the morbidity and mortality associated with incorrect diagnoses. Missing a malignant biliary stricture may delay surgery, resulting in poor prognostic outcomes. Conversely, it has been demonstrated that approximately 20% of patients who undergo surgery for suspected biliary malignancies have a benign etiology on histopathology. Traditional tissue sampling using endoscopic retrograde cholangiography does not always produce a definitive diagnosis, with a considerable proportion of cases remaining as indeterminate biliary strictures. Recent advances in endoscopic techniques have the potential to improve the diagnostic and prognostic accuracy of biliary strictures.

Tissue sampling for biliary strictures using novel elbow biopsy forceps

We aim to evaluate the safety and feasibility of novel elbow biopsy forceps with a prebent head for sampling biliary strictures in our institution. A total of 24 patients (15 males and 9 females) with biliary stricture who underwent biliary biopsy during endoscopic retrograde cholangiopancreatography (ERCP) using novel elbow biopsy forceps from June 2019 to August 2020 were retrospectively included. The novel biopsy forceps had a head angulation of 30 degrees and were able to cannulate the bile duct and approach the biliary strictures easily to obtain adequate samples. The technical success rate, incidence of adverse events, and consistency of pathological and surgical specimens were assessed. This device was used successfully in all patients. A total of 52 biopsy specimens were obtained from 24 patients, and all specimens could be used for histopathological examination. Seventeen patients were diagnosed with malignancy based on biopsies, and all of them underwent surgical treatment. The histopathological findings of the biopsy specimens were in accordance with the postoperative pathology diagnoses. One of the seven patients was diagnosed with a benign lesion that was proven to be malignant during surgical treatment in the follow-up period. Two patients experienced a single episode of acute pancreatitis and recovered shortly after appropriate treatment. No patients experienced biliary perforation or biliary bleeding. Biopsy using novel elbow forceps in patients with biliary stenosis is feasible and safe. The novel device and related biopsy technique may be widely applied for biliary disease differentiation.

High sensitivity of ROSE-supported ERCP-guided brushing for biliary strictures

Background and study aims  Endoscopic retrograde cholangiopancreatography (ERCP) plays a major role in biliary strictures, with brushing being a cheap and fast method to acquire a cytological specimen, despite a sensitivity around 45 %. Rapid on-site evaluation (ROSE) is widely used for endoscopic ultrasound-acquired cytological specimen adequacy, improving its sensitivity and specificity. Nevertheless, no study has evaluated its role for ERCP-guided brushing. Our aim was to assess the diagnostic yield of ERCP-guided brushing of biliary strictures when supported by ROSE. Patients and methods  This was a retrospective single-center study that included patients undergoing ERCP-guided brush cytology supported by ROSE for biliary strictures. Recorded data included patient clinical-radiological and ERCP features. Final diagnosis was determined after surgery, intraductal biopsy or adequate follow-up. The diagnostic yield was calculated and a subgroup analysis for factors associated with false-negative or true-positive results was performed. Results  Two hundred six patients were included, 57.3 % males, median age 72 years, 77.2 % having extrahepatic biliary strictures. Of the patients, 99 % had an adequate sample at ROSE after a mean of 2.6 passages. The diagnostic yield was accuracy 83 %, sensitivity 74.6 %, and specificity 98 %, positive and negative predictive values 98 % and 71 % respectively, with an area under the curve of 0.86. A diagnosis of cholangiocarcinoma was significantly more frequent among true-positive cases (68 % vs 46.8 %; P  = 0.04). Conclusions  This is the first study evaluating the use of ROSE as support for ERCP-guided brushing of biliary strictures, with a sensitivity far higher than those reported for brushing alone and at least comparable to those of more expensive and invasive techniques.

Digital Image Analysis has an Additive Beneficial Role to Conventional Cytology in Diagnosing the Nature of Biliary Ducts Stricture

BACKGROUND & AIM

Conventional cytological evaluation (CCE) fails to identify nature indeterminate biliary duct stricture (IBDS) in many cases. Digital image analysis (DIA) has the ability to identify and analyze the DNA content of cells. This study assesses the role of DIA in recognizing the nature of IBDS compared to CCE.

METHODS

A prospective observational study was conducted at the Al-Rajhi University Hospital. Fifty patients with IBDS, based on abdominal imaging, were subjected to endoscopic retrograde cholangiopancreatography (ERCP) and brush sampling. These samples were evaluated with CCE and DIA. Follow-up for at least 9 months and cost-analysis had also been done.

RESULTS

Based on the final diagnosis, 32 (64.0%) patients had malignant stricture, and 39 (78.0%) had distal stricture. DIA had 84.40% (95% CI; 67.20-94.70) sensitivity and 94.40% (95% CI; 72.70-99.90) specificity in identifying nature of IBDS, whereas CCE had 19.0% (95% CI; 7.20-36.40) sensitivity and 89.0% (95% CI; 65.30-98.60) specificity. Combination of both modalities had 84.40% (95% CI; 67.20-94.70) sensitivity and 83.30% (95% CI; 58.60-96.40) specificity in identification nature of IBDS. Based on CCE alone, only 6/32 (18.80%) of malignant stricture were diagnosed, and 26/32 (81.20%) were missed. However, DIA alone was able to diagnose 27/32 (84.40%) of malignant stricture, and only 5 cases were missed. Both procedures had detection rate of malignant stricture as DIA alone. Benign stricture was correctly diagnosed in 16/18 (88.80%), 17/18 (94.40%), and 15/18 (83.30%) using CCE alone, DIA alone, and both procedures together, respectively. Cost per detection additional one malignant stricture using DIA required 99.4$.

CONCLUSION

DIA is substantially better than CCE in diagnosing the nature of IBDS but at an increase cost and thus suggests its application in a wider role in clinical practice.

CLINICAL TRIAL NUMBER

NCT04112030.

Locally Advanced Pancreatic Ductal Adenocarcinoma: Challenges and Progress

Pancreatic ductal adenocarcinoma (PDAC) is one of the major causes of death in the Western world, and it is estimated to become the second leading cause of tumour-related mortality in the next 10 years. Among pancreatic cancers, ductal adenocarcinomas are by far the most common, characterised by a challenging diagnosis due to the lack of initial and pathognomonic clinical signs. In this scenario, non-metastatic locally advanced pancreatic cancer (LAPC) accounts for a large proportion of all new pancreatic ductal adenocarcinoma diagnoses. There is no consensus on a common definition of LAPC. Still, it usually includes tumours that are not resectable due to vascular involvement. As of today, treatment is limited, and the prognosis is very unfavourable. Curative-intent surgery remains the gold-standard even if often jeopardized by vascular involvement. Continuing progress in our understanding of LAPC genetics and immunology will permit the development of different treatments, targeted or combined, including radiation therapy, hadrontherapy, targeted immunotherapies or new chemotherapies. A multidisciplinary approach combining various fields of expertise is essential in aiming to limit disease progression as well as patient outcome. Using a narrative literature review approach, the manuscript explores the most up-to-date knowledge concerning locally advanced pancreatic ductal adenocarcinoma management.

Adequate tissue acquisition rate of peroral cholangioscopy-guided forceps biopsy

Background

Peroral cholangioscopy (POCS)-guided forceps biopsy is a method for diagnosing indeterminate biliary strictures and for the preoperative identification of the exact perihilar and distal margins of biliary tract cancer (BTC). However, POCS-guided forceps biopsy may result in an insufficient amount of specimen at times. Therefore, we evaluated the adequate tissue acquisition rate and the factors affecting the adequate tissue acquisition of POCS-guided forceps biopsy for the biliary tract.

Methods

Patients who underwent POCS-guided forceps biopsy for biliary disease between September 2016 and October 2018 at our hospital were enrolled retrospectively. We evaluated the adequate tissue acquisition rate of POCS-guided forceps biopsy for the biliary lesion and that for non-stenotic bile duct. In addition, the factors affecting the adequate tissue acquisition rate of POCS-guided forceps biopsy were evaluated.

Results

We enrolled 47 patients with biliary disease and performed POCS-guided forceps biopsy for biliary lesion and POCS-guided forceps mapping biopsy for non-stenotic bile duct in 40 and 36 patients, respectively. The adequate tissue acquisition rates of POCS-guided forceps biopsy for biliary lesions and that for non-stenotic bile duct were 86.4%, and 68.9%, respectively. In the multivariate logistic regression analyses, age, and previous biliary stenting before POCS were factors affecting the adequate tissue acquisition rate of POCS-guided forceps biopsy for the biliary lesion. For non-stenotic bile duct, the location of the biliary lesion, endoscopic sphincterotomy (EST), and procedure time of POCS were factors affecting the adequate tissue acquisition rate of POCS-guided forceps mapping biopsy.

Conclusions

Previous biliary stenting was a factor affecting a low tissue acquisition rate of POCS-guided forceps biopsy for the biliary lesion. In the POCS-guided forceps mapping biopsy, the location of the biliary lesion, EST, and procedure time were factors affecting tissue acquisition rates.

Peroral cholangioscopy-guided forceps biopsy versus fluoroscopy-guided forceps biopsy for extrahepatic biliary lesions

Background and Aim

Endoscopic retrograde cholangiopancreatography (ERCP)‐related tissue acquisition, including fluoroscopy‐guided forceps biopsy (F‐FB), is a common technique in diagnosing indeterminate biliary lesions. Recently, peroral cholangioscopy (POCS) and POCS‐guided forceps biopsy (POCS‐FB) has also been used for the diagnosis of indeterminate biliary lesions. However, it is uncertain which of those techniques were superior for the diagnosis of extrahepatic cholangiocarcinoma (ECC). We aimed to evaluate the diagnostic yield and safety of F‐FB for indeterminate biliary lesions compared with POCS‐FB.

Methods

Patients who underwent F‐FB or POCS‐FB to evaluate indeterminate biliary lesions between October 2011 and August 2019 were enrolled retrospectively. We carried out propensity score matching to balance these clinical differences between the F‐FB group and POCS‐FB group. In the propensity score‐matched cohort, we compared the diagnostic performance of F‐FB with that of POCS‐FB based on the pathological evaluation. We also evaluate adverse events associated with F‐FB and POCS‐FB.

Results

We enrolled 113 patients with biliary diseases, and 62 patients were analyzed in the propensity score‐matched cohort. Sensitivity, specificity, and accuracy of F‐FB were 82.4, 100, and 90.3%, and for POCS‐FB, those values were 83.3, 100, and 90.3%, respectively. There were no significant differences in the diagnostic performance between F‐FB and POCS‐FB. There were also no significant differences in the occurrence of adverse events between F‐FB and POCS‐FB (41.9 vs 29.0%, P = 0.289).

Conclusions

The diagnostic yield of F‐FB for ECC is similar to that of POCS‐FB. POCS‐FB is not necessary for the initial pathological diagnosis of indeterminate biliary lesions.

New staining method using methionyl-tRNA synthetase 1 antibody for brushing cytology of bile duct cancer

BACKGROUND AND AIMS

Identifying malignant biliary strictures using endobiliary brushing cytology specimens is important for treatment decision-making and prognosis prediction. The sensitivity of brushing cytology specimens based on Papanicolaou (Pap) staining is low, which hampers accurate diagnosis of indeterminate strictures. Here, we assessed the diagnostic value of immunohistochemical (IHC) and immunofluorescence (IF) staining for methionyl-tRNA synthetase 1 (MARS1).

METHODS

Endobiliary brushing cytology specimens were obtained during ERCP from 80 patients with an extrahepatic biliary stricture. Pap and MARS1 IF staining were performed on liquid-based cytology slides derived from these specimens. Sections of bile duct adenocarcinoma and normal bile duct tissue were obtained from 45 patients who underwent surgery for malignant biliary stricture, and MARS1 levels were evaluated by IHC staining.

RESULTS

MARS1 IF staining was applied to brushing cytology specimens, and the results showed strong signals in malignant biliary structures but not in the negative for malignancy specimens. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 70.4%, 96.2%, 97.4%, 56.8%, and 78.8%, respectively, for conventional Pap staining and 98.1%, 96.1%, 98.1%, 96.2%, and 97.5%, respectively, for MARS1 IF (P < .0001). When IHC staining was used, MARS1 was detected in 45 bile duct adenocarcinoma sections but not in 15 normal bile duct sections. Moreover, MARS1 mRNA and protein levels were significantly higher in bile duct adenocarcinoma sections according to polymerase chain reaction and Western blot, respectively.

CONCLUSIONS

The high sensitivity and accuracy of MARS1 IF staining enabled detection of malignancy in patients with indeterminate biliary stricture. Further prospective studies are needed to validate our findings. (Clinical trial registration number: KCT 0003285.).

Targeted Therapies in Advanced Biliary Tract Cancer: An Evolving Paradigm

Biliary tract cancers (BTCs) are a heterogeneous group of adenocarcinomas that originate from the epithelial lining of the biliary tree. BTCs are characterized by presentation with advanced disease precluding curative surgery, rising global incidence, and a poor prognosis. Chemotherapy is the mainstay of the current treatment, which results in a median overall survival of less than one year, underscoring the need for novel therapeutic agents and strategies. Next-generation sequencing-based molecular profiling has shed light on the underpinnings of the complex pathophysiology of BTC and has uncovered numerous actionable targets, leading to the discovery of new therapies tailored to the molecular targets. Therapies targeting fibroblast growth factor receptor (FGFR) fusion, isocitrate dehydrogenase (IDH) mutations, the human epidermal growth factor receptor (HER) family, DNA damage repair (DDR) pathways, and BRAF mutations have produced early encouraging results in selected patients. Current clinical trials evaluating targeted therapies, as monotherapies and in combination with other agents, are paving the way for novel treatment options. Genomic profiling of cell-free circulating tumor DNA that can assist in the identification of an actionable target is another exciting area of development. In this review, we provide a contemporaneous appraisal of the evolving targeted therapies and the ongoing clinical trials that will likely transform the therapeutic paradigm of BTC.

Advances in the endoscopic management of malignant biliary obstruction

Biliary obstruction is common in pancreatobiliary malignancies and has a negative impact on the patient's quality of life, postoperative complications, and survival rates. Particularly in the last decade, there has been enormous progress regarding the diagnostic and therapeutic options in patients with malignant biliary obstruction. Endoscopy has given a new insight in this direction and novel techniques have been developed for the better characterization and treatment of malignant strictures. We herein summarize the available data on the different endoscopic techniques, and clarify their role in the diagnosis and treatment of malignant biliary obstructive disease. Finally, we propose an algorithm that can facilitate management decisions in these patients.

Efficacy of digital single-operator cholangioscopy and factors affecting its accuracy in the evaluation of indeterminate biliary stricture

BACKGROUND AND AIMS

Indeterminate biliary stricture remains a significant diagnostic challenge. The current method of ERCP with bile duct brush cytology has substantial room for improvement. We aimed to determine the efficacy of a digital single-operator cholangioscopy (DSOC) in evaluation of indeterminate biliary stricture.

METHODS

An observational cohort study was conducted among the patients who underwent DSOC for the indication of indeterminate biliary stricture at a tertiary academic medical center. The outcomes of interests were the accuracy of DSOC in visual interpretation and bile duct sample and identification of any factor(s) that could influence its effectiveness.

RESULTS

One hundred five patients were included. The overall accuracy of DSOC in visual interpretation was 89.5%, whereas the accuracy of bile duct sample was 83.2%. The sensitivities of visual impression and bile duct sample were 89.1% and 69.8% and their specificities were 90% and 97.9%, respectively. The degree of endoscopists' experience with fewer than 25 cases and the severity of hyperbilirubinemia negatively impacted the accuracy of DSOC. Among 55 patients with definitive diagnosis of malignant stricture, the sensitivity of combined intraductal forceps biopsy sampling and brush cytology was 80.6%, whereas the sensitivity of brush cytology alone was 47.1%.

CONCLUSIONS

DSOC augments ERCP in evaluating indeterminate biliary stricture. The acquisition of intraductal forceps biopsy samples should be a requisite in evaluation of indeterminate biliary stricture with DSOC. Discovery of modifiable factors such as the degree of endoscopists' expertise and the severity of hyperbilirubinemia, which can influence the accuracy of DSOC, warrants further studies on patient preprocedure optimization and an endoscopic training program that will cultivate procedural competency.

Ethanol-based fixation is superior to conventional brush cytology in the evaluation of indeterminate biliary strictures by endoscopic retrograde cholangiography

The aim of this study was to compare the diagnostic yield of conventional cytology (CC) with ethanol-based fixation, a cytological analysis using an ethanol based fixative system including a cell block procedure (EBF) to evaluate indeterminate biliary strictures (IBStr). We also compared additionally taken fluorescence-guided forceps biopsies (FB) with EBF concerning a potential additive diagnostic benefit.Early detection and accurate diagnosis are crucial for patients with suspected carcinoma within the biliary tree to preserve curative treatment options but diagnostics and patient care in the evaluation of IBStr are still challenging. ERC-guided brush cytology is the gold standard of nonsurgical evaluation of IBStr. However, accuracy is generally low. New specimen processing's are needed to higher the diagnostic yield in the evaluation of IBStr.We performed a retrospective evaluation in 404 patients referred for further diagnosis of IBStr. Gold standard was defined as surgically obtained histology or patient follow-up of at least 1 year to diagnose or exclude malignancy.Three hundred thirty-four patients were included into the final analysis. One hundred seventy-two strictures were malignant, 162 strictures benign. One hundred seventeen specimens were evaluated by CC, 217 processed by EBF. EBF performed significantly better in terms of sensitivity (24.6% vs 60%, P < .001) and accuracy (59.0% vs 75.1%, P = .006). Fifty-eight FB were additionally taken and showed a numerically improved sensitivity compared to EBF alone (80% vs 62.9%, P = .19).EBF is a simple and inexpensive technique that substantially improved sensitivity and accuracy in the evaluation of IBStr. FB specimen did not significantly improve diagnostic yield.

Early Diagnosis And Management Of Malignant Distal Biliary Obstruction: A Review On Current Recommendations And Guidelines

Malignant biliary obstruction is a challenging condition, requiring a multimodal approach for both diagnosis and treatment. Pancreatic adenocarcinoma and cholangiocarcinoma are the leading causes of malignant distal biliary obstruction. Early diagnosis is difficult to establish as biliary obstruction can be the first presentation of the underlying disease, which can already be at an advanced stage. Consequently, the majority of patients (70%) with malignant distal biliary obstruction are unresectable at the time of diagnosis. The association of clinical findings, laboratory tests, imaging, and endoscopic modalities may help in identifying the underlying cause. Novel endoscopic techniques such as cholangioscopy, intraductal ultrasonography, or confocal laser endomicroscopy have been developed with promising results, but are not used in routine clinical practice. As the number of patients with malignant distal biliary obstruction who will undergo curative surgery is limited, endoscopy has a crucial role in palliation, to relieve biliary obstruction. According to the last European guidelines published in the management of biliary obstruction, self-expandable metal stents have a central place in biliary drainage compared to plastic stents. Endoscopic ultrasound has evolved impressively in the last decades. When standard techniques of biliary cannulation by endoscopic retrograde cholangiopancreatography fail, endoscopic ultrasound-guided biliary drainage is a good option compared to percutaneous drainage.

The value of DNA image cytometry combined with brush routine cytology in diagnosing indeterminate biliary strictures: A large sample size retrospective study

BACKGROUND AND AIM

Brush cytology is widely applied to diagnosis indeterminate biliary stricture but suffer from low sensitivity. Changes in DNA content are a character of malignant cell and can be detected by DNA image cytometry (DNA-ICM). The study aimed to estimate the value of routine cytology (RC), DNA-ICM, and their combination in diagnosing indeterminate biliary strictures.

METHODS

A total of 362 patients who underwent both RC and DNA-ICM tests were analysed. Their results were retrospectively applied to final diagnoses. Diagnostic values were compared among RC, DNA-ICM, and their combination based on the location of strictures.

RESULTS

The DNA-ICM and combination of two methods had higher diagnostic accuracy than RC in all strictures (63.3% vs 42.3%, P < 0.001, 64.36% vs 42.3%, P < 0.001) and in distal strictures (65.36% vs 42.81%, P < 0.001, 66.01% vs 42.81%, P < 0.001). But in proximal strictures, DNA-ICM showed no superior (51.8% vs 42.81%, P = 0.184). Combination of two methods was not fully significant superior to RC in proximal strictures (55.36% vs 39.29%, P = 0.089). After classification of "suspicious for malignancy" as positive for malignancy, the diagnostic accuracy of DNA-ICM was still higher than that of RC in all strictures (63.3% vs 51.9%, P = 0.002) and in distal strictures (65.36% vs 52.29%, P = 0.001). Combination of two methods was no superior to DNA-ICM alone (64.36% vs 63.3%, P = 0.757). The utilization of DNA-ICM was more accurate in distal strictures than in proximal strictures (65.36% vs 51.8%, P = 0.017).

CONCLUSION

DNA-ICM is an objective and effective addition tool with RC, especially in distal strictures. The combination of DNA-ICM and RC showed no superior to DNA-ICM alone but could improve diagnostic accuracy to RC in proximal strictures although not fully significant.