Role of Fluorescent In Situ Hybridization, Cholangioscopic Biopsies, and EUS-FNA in the Evaluation of Biliary Strictures

Comparison of fluorescence in situ hybridization and cytology for the accurate detection of malignant biliary strictures, with emphasis on unusual results

INTRODUCTION

Biliary brushing cytology is the standard diagnostic approach for evaluating biliary strictures, but it has low sensitivity and a high rate of atypical diagnoses. Fluorescence in situ hybridization (FISH) has become an increasingly valuable adjunct to cytology. Therefore, the aim of this retrospective quality improvement study was to evaluate the relative diagnostic performance of traditional cytology and FISH for correctly determining malignant versus benign biliary strictures from biliary brushing samples and to evaluate whether adding FISH to the diagnostic pipeline improves diagnostic accuracy over relying on cytology alone.

MATERIALS AND METHODS

We conducted a retrospective study of biliary brushing and FISH results in patients evaluated for biliary strictures between April 2019 and March 2023.

RESULTS

A total of 228 specimens were retrieved. For cytology results: 151 negative, 55 atypical, 6 suspicious, and 16 positive. For FISH results: 105 negative, 71 equivocal, and 52 positive. When calculating performance measures, cytology atypical and FISH equivocal were excluded; cytology suspicious was considered positive. The sensitivity and specificity of cytology were 45.8% and 100%, respectively. The sensitivity and specificity of FISH were 84.2% and 96.0%, respectively.

CONCLUSIONS

Our findings indicate that FISH exhibits considerably higher diagnostic sensitivity than routine cytology in identifying malignant biliary strictures. Furthermore, combining cytology with FISH may provide a more comprehensive diagnostic approach, reducing the likelihood of false-negative results. However, positive and equivocal FISH results should be interpreted carefully and considered alongside more specific cytology findings to minimize the risk of false-positive diagnoses.

Risk of malignancy in indeterminate biliary tract strictures: Retrospective cohort study

BACKGROUND

Indeterminate biliary strictures, that is, a stricture with benign brush cytology but without clear etiology in clinical or radiological assessment, pose a challenge for clinicians. This study aimed to assess the incidence and risk factors for malignant disease in patients with indeterminate biliary strictures.

METHODS

This is a single-center retrospective study of patients with indeterminate biliary stricture undergoing first endoscopic retrograde cholangiopancreatography (ERCP) and biliary brushing between March 2011 and March 2020. The study included patients with atypical cytology in the first ERCP biliary brushing samples. Main exclusion criteria were primary sclerosing cholangitis, apparent malignancy or tumor in imaging studies, postoperative strictures, chronic pancreatitis, biliary tract stone, and no ≥12-month follow-up or a final pathological diagnosis.

RESULTS

A total of 2279 patients underwent first ERCP procedure because of a biliary tract stricture during the study period, of which 51 patients (2.2%) had an indeterminate biliary stricture and were included. A total of 30 patients (58.8%) had final diagnosis of malignant disease. The patients with final diagnosis of malignant disease were mostly men (n = 19, 63.3%), had jaundice (n = 25, 86.2%), and had significantly higher bilirubin and CA19-9 values than those with benign disease. A total of 25 patients were operated on, of which 21 patients (84%) had malignant disease. Twenty-six patients were followed up only, of whom nine patients (34.6%) had a malignant disease.

CONCLUSION

Indeterminate biliary strictures are uncommon, but two-thirds of the initially indeterminate biliary strictures are malignant. The presence of clinical jaundice and elevated bilirubin and CA19-9 values are associated with increased risk of malignancy.

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.

Implementing Massive Parallel Sequencing into Biliary Samples Obtained through Endoscopic Retrograde Cholangiopancreatography for Diagnosing Malignant Bile Duct Strictures

Despite advancements in radiologic, laboratory, and pathological evaluations, differentiating between benign and malignant bile duct strictures remains a diagnostic challenge. Recent developments in massive parallel sequencing (MPS) have introduced new opportunities for early cancer detection and management, but these techniques have not yet been rigorously applied to biliary samples. We prospectively evaluated the Oncomine Comprehensive Assay (OCA) and the Oncomine Pan-Cancer Cell-Free Assay (OPCCFA) using biliary brush cytology and bile fluid obtained via endoscopic retrograde cholangiopancreatography from patients with bile duct strictures. The diagnostic performance of MPS testing was assessed and compared to the pathological findings of biliary brush cytology and primary tissue. Mutations in TP53, BRAF, CTNNB1, SMAD4, and K-/N-RAS identified in biliary brush cytology samples were also detected in the corresponding bile fluid samples from patients with extrahepatic cholangiocarcinoma. These mutations were also identified in the bile fluid samples, but with variant allele frequencies lower than those in the corresponding biliary brush cytology samples. In control patients diagnosed with gallstones, neither the biliary brush cytology samples nor the bile fluid samples showed any pathogenic mutations classified as tier 1 or 2. Our study represents a prospective investigation into the role of MPS-based molecular testing in evaluating bile duct strictures. MPS-based molecular testing shows promise in identifying actionable genomic alterations, potentially enabling the stratification of patients for targeted chemotherapeutic treatments. Future research should focus on integrating OCA and OPCCFA testing, as well as similar MPS-based assays, into existing surveillance and management protocols for patients with bile duct strictures.

Endoscopic evaluation of indeterminate biliary strictures: Cholangioscopy, endoscopic ultrasound, or both?

Accurate and timely diagnosis of biliary strictures can be challenging. Because the diagnostic sensitivity and accuracy of standard endoscopic retrograde cholangiopancreatography-based tissue sampling for malignancy are suboptimal, additional endoscopic evaluation by cholangioscopy and/or endoscopic ultrasound (EUS) is often necessary to differentiate between malignant and benign biliary strictures to guide clinical management. While direct visualization by cholangioscopy and/or high-resolution imaging by EUS are often the first step in the evaluation of an indeterminate biliary stricture (IDBS), tissue diagnosis by cholangioscopy-guided biopsy and/or EUS-guided fine-needle tissue acquisition is the preferred modality to establish a diagnosis of malignancy. Because each modality has its own strengths and limitations, selection of cholangioscopy and EUS is best guided by the biliary stricture location and local expertise. Artificial intelligence-assisted diagnosis, biopsy forceps with improved design, contrast-enhanced EUS, and dedicated fine-needle biopsy devices are recent technological advances that may further improve the diagnostic performance of cholangioscopy and EUS in patients with IDBS.

Performance of fluorescence in situ hybridization in biliary brushings with equivocal cytology: an institutional experience

INTRODUCTION

Biliary brushing (BB) cytology has a sensitivity of 15%-65% and specificity approaching 100% for detecting malignancy. Fluorescence in-situ hybridization (FISH) using the UroVysion probe set has been advocated to enhance the detection of malignancies with reported sensitivity of 43%-84%. We sought to evaluate the performance of FISH in BB with equivocal cytology at our institution.

MATERIALS AND METHODS

Patients with atypical and suspicious BB with concurrent diagnostic FISH performed at our institution from 2014 to 2021 were identified through a query of our pathology database. FISH (using UroVysion probe set containing centromere enumeration probes to chromosomes 3, 7, and 17) was positive if at least 5 cells demonstrated polysomy. Electronic medical records were reviewed for pathology results and outcomes. Patients were classified malignant if they had positive pathology or documented clinical impression of malignancy and benign if they had negative pathology and/or documented benign clinical course for at least 12 months.

RESULTS

We identified 254 equivocal BB (238 atypical/16 suspicious) with concurrent FISH results from 191 patients (105 benign, 86 malignant). 12% (22/191) of patients were FISH positive. Twenty-four percent (21/86) of patients with malignancy had positive FISH but were nonspecific for pancreaticobiliary/ampullary adenocarcinomas. Almost all positive FISH were associated with malignancy (21/22; 95%). There was 1 positive FISH in a patient with primary sclerosing cholangitis who had a benign outcome.

CONCLUSIONS

The small number of positive FISH results in BB with equivocal cytology raises the question of the optimal criteria for malignancy. Using only polysomy could result in lower sensitivity.

Practical considerations for pathological diagnosis and molecular profiling of cholangiocarcinoma: an expert review for best practices

INTRODUCTION

Advances in precision medicine have expanded access to targeted therapies and demand for molecular profiling of cholangiocarcinoma (CCA) patients in routine clinical practice. However, pathologists face challenges in establishing a definitive intrahepatic CCA (iCCA) diagnosis while preserving sufficient tissue for molecular profiling. Additionally, they frequently face challenges in optimal tissue handling to preserve nucleic acid integrity.

AREAS COVERED

This article first identifies the challenges in establishing a definitive diagnosis of iCCA in a lesional liver biopsy while preserving sufficient tissue for molecular profiling. Then, the authors explore the clinical value of molecular profiling, the basic principles of single gene and next-generation sequencing (NGS) techniques, and the challenges in tissue sampling for genomic testing. They also propose an algorithm for best practice in tissue management for molecular profiling of CCA.

EXPERT OPINION

Several practical challenges face pathologists during tissue sampling and processing for molecular profiling. Optimized tissue processing, careful tissue handling, and selection of appropriate approaches to molecular testing are essential to ensure that the highest possible quality of diagnostic information is provided in the greatest proportion of cases.

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.

Cholangiocarcinoma Surveillance Recommendations in Patients with Primary Sclerosing Cholangitis

Cholangiocarcinoma (CCA) is a deadly complication observed in the setting of primary sclerosing cholangitis (PSC). When symptoms develop and CCA is diagnosed, it is usually at an advanced stage. Median survival is less than 12 months. Early identification of CCA leads to improved outcomes. Although diagnostic tests have excellent specificity, they are plagued by low sensitivity. No surveillance strategies have been widely agreed upon, but most societies recommend measurement of serum carbohydrate antigen 19-9 and MRCP every 6 to 12 months in patients with PSC. Advances in understanding of the genetic factors that lead to CCA are awaited.

Current Standards, Multidisciplinary Approaches, and Future Directions in the Management of Extrahepatic Cholangiocarcinoma

OPINION STATEMENT

Biliary tract cancers are molecularly and anatomically diverse cancers which include intrahepatic cholangiocarcinoma, extrahepatic (perihilar and distal) cholangiocarcinoma, and gallbladder cancer. While recognized as distinct entities, the rarer incidence of these cancers combined with diagnostic challenges in classifying anatomic origin has resulted in clinical trials and guideline recommended strategies being generalized patients with all types of biliary tract cancer. In this review, we delve into the unique aspects, subtype-specific clinical trial outcomes, and multidisciplinary management of patients with extrahepatic cholangiocarcinoma. When resectable, definitive surgery followed by adjuvant chemotherapy (sometimes with selective radiation/chemoradiation) is current standard of care. Due to high recurrence rates, there is growing interest in the use of upfront/neoadjuvant therapy to improve surgical outcomes and to downstage patients who may not initially be resectable. Select patients with perihilar cholangiocarcinoma are being successfully treated with novel approaches such as liver transplant. In the advanced disease setting, combination gemcitabine and cisplatin remains the standard base for systemic therapy and was recently improved upon with the addition of immune checkpoint blockade to the chemotherapy doublet in the recently reported TOPAZ-1 and KEYNOTE-966 trials. Second-line all-comer treatments for these patients remain limited in both options and efficacy, so clinical trial participation should be strongly considered. With increased use of molecular testing, detection of actionable mutations and opportunities to receive indicated targeted therapies are on the rise and are the most significant driver of improved survival for patients with advanced stage disease. Though these targeted therapies are currently reserved for the second or later line, future trials are looking at moving these to earlier treatment settings and use in combination with chemotherapy and immunotherapy. In addition to cross-disciplinary management with surgical, medical, and radiation oncology, patient-centered care should also include collaboration with advanced endoscopists, palliative care specialists, and nutritionists to improve global patient outcomes.

British Society of Gastroenterology guidelines for the diagnosis and management of cholangiocarcinoma

These guidelines for the diagnosis and management of cholangiocarcinoma (CCA) were commissioned by the British Society of Gastroenterology liver section. The guideline writing committee included a multidisciplinary team of experts from various specialties involved in the management of CCA, as well as patient/public representatives from AMMF (the Cholangiocarcinoma Charity) and PSC Support. Quality of evidence is presented using the Appraisal of Guidelines for Research and Evaluation (AGREE II) format. The recommendations arising are to be used as guidance rather than as a strict protocol-based reference, as the management of patients with CCA is often complex and always requires individual patient-centred considerations.

Using Endoscopy in the Diagnosis of Pancreato-Biliary Cancers

Pancreatic cancer and cholangiocarcinoma are life threatening oncological conditions with poor prognosis and outcome. Pancreatic cystic lesions are considered precursors of pancreatic cancer as some of them have the potential to progress to malignancy. Therefore, accurate identification and classification of these lesions is important to prevent the development of invasive cancer. In the biliary tract, the accurate characterization of biliary strictures is essential for providing appropriate management and avoiding unnecessary surgery. Techniques have been developed to improve the diagnosis, risk stratification, and management of pancreato-biliary lesions. Endoscopic ultrasound (EUS) and associated techniques, such as elastography, contrasted-enhanced EUS, and EUS-guided needle confocal laser endomicroscopy, may improve diagnostic accuracy. In addition, intraductal techniques applied during endoscopic retrograde cholangiopancreatography (ERCP), such as new generation cholangioscopy and in vivo cellular evaluation through probe-based confocal laser endomicroscopy, can increase the diagnostic yield in characterizing indeterminate biliary strictures. Both EUS-guided and intraductal approaches can provide the possibility for tissue sampling with new tools, such as needles, biopsies forceps, and brushes. At the molecular level, novel biomarkers have been explored that provide new insights into diagnosis, risk stratification, and management of these lesions.

Endoscopic Ultrasound in the Diagnosis of Extrahepatic Cholangiocarcinoma: What Do We Know in 2023?

Extrahepatic cholangiocarcinoma (CCA) is a rare and aggressive type of cancer, presenting as a mass or as a biliary stricture. This review summarizes the utility of endoscopic ultrasound (EUS) in the detection, staging, and determination of the differential diagnosis, especially when no cause of bile duct dilatation is revealed by cross-sectional imaging. The EUS detection rate for distal CCAs is higher than that for the proximal CCAs. The accuracy of T staging varies between 60 and 80%, and vascular involvement is correctly assessed by conventional EUS. EUS-tissue acquisition from the primary tumors is reserved for unresectable or metastatic CCA, especially in distal strictures or mass CCAs. For proximal lesions, EUS could be performed as an adjunctive to ERCP sampling when the latter is inconclusive. EUS is not appropriate for assessing the malignant features of lymph nodes in CCAs. Lymph node EUS-tissue acquisition should be performed only if it changes the surgical decision. Perhaps the development of EUS-fine needle biopsy and the detection of molecular genetic alteration will increase the diagnostic yield in CCAs.

Advanced endoscopy meets molecular diagnosis of cholangiocarcinoma

Cholangiocarcinoma remains an aggressive and deadly malignancy that is often diagnosed late. Intrinsic tumour characteristics and the growth pattern of cancer cells contribute to the challenges of diagnosis and chemoresistance. However, establishing an early and accurate diagnosis, and in some instances identifying targetable changes, has the potential to impact survival. Primary sclerosing cholangitis, a chronic cholangiopathy prodromal to the development of a minority of cholangiocarcinomas, poses a particular diagnostic challenge. We present our diagnostic and theranostic approach to the initial evaluation of cholangiocarcinomas, focusing on extrahepatic cholangiocarcinoma. This involves a multipronged strategy incorporating advanced imaging, endoscopic methods, multiple approaches to tissue sampling, and molecular markers. We also provide an algorithm for the sequential use of these tools.

Clinical characteristics, risk factors and diagnostic outcomes of patients presented with indeterminate biliary stricture: A multicenter study

BACKGROUND AND AIM

Indeterminate biliary stricture (IBS) is a frequently encountered clinical problem. In this study, we aimed to highlight the clinical characteristics, risk factors and diagnostic outcomes of patients presented with indeterminate biliary stricture.

METHOD

A Retrospective multicenter study included all patients diagnosed with IBS in the participating centers between 2017 and 2021. Data regarding IBS such as presentations, patient characteristics, diagnostic and therapeutic modalities were collected from the patients' records and then were analyzed.

RESULTS

Data of 315 patients with IBS were retrospectively collected from 7 medical centers with mean age: 62.6 ± 11 years, females: 40.3% and smokers: 44.8%. For diagnosing stricture; Magnetic resonance imaging/Magnetic resonance cholangiopancreatography (MRI/MRCP) was the most frequently requested imaging modality in all patients, Contrast enhanced computerized tomography (CECT) in 85% and endoscopic ultrasound (EUS) in 23.8%. Tissue diagnosis of cholangiocarcinoma was achieved in 14% only. The used therapeutic modalities were endoscopic retrograde cholangiopancreatography (ERCP)/stenting in 70.5%, percutaneous trans-hepatic biliary drainage (PTD): 17.8%, EUS guided drainage: 0.3%, and surgical resection in 8%. The most frequent type of strictures was distal stricture in 181 patients, perihilar in 128 and intrahepatic in 6. Distal strictures had significant male predominance, with higher role for EUS for diagnosis and higher role for ERCP/stenting for drainage, while in the perihilar strictures, there was higher role for CECT and MRI/MRCP for diagnosis and more frequent use of PTD for drainage.

CONCLUSION

Indeterminate biliary stricture is a challenging clinical problem with lack of tissue diagnosis in most of cases mandates an urgent consensus diagnostic and treatment guidelines.

Usefulness of Liquid-Based Cytology in Diagnosing Biliary Tract Cancer Compared to Conventional Smear and Forceps Biopsy

BACKGROUND/AIMS

Liquid-based cytology (LBC) has been shown to improve the diagnostic efficacy of brush cytology for thyroid, cervical and pancreatic cancer. To evaluate the diagnostic performance of LBC for biliary tract cancer, we compared it with conventional smears and forceps biopsies.

METHODS

A retrospective study was conducted of all consecutive patients who underwent brush cytology under ERCP from January 2010 to April 2020. The primary outcome was the diagnostic efficacy of conventional smears and LBC. The difference between the two groups was corrected using inverse probability weighting (IPW). The secondary outcome was the sensitivity and specificity of brush cytology and forceps biopsy. The secondary outcome was evaluated in patients who underwent both methods.

RESULTS

Among 162 patients, conventional smears were performed in 70 patients and LBC was performed in 92 patients. In the primary analysis using IPW, the sensitivity of conventional smears and LBC was 56.00% and 78.26% respectively (P = 0.009). The specificity was 100% for both methods. The accuracy was 66.15% for conventional smears and 83.33% for LBC (P = 0.012). In the secondary analysis, the sensitivity of conventional smears versus forceps biopsies was 62.16% versus 78.38% (P = 0.034) and 81.16% for both LBC and forceps biopsies. The specificity of both cytological examination and forceps biopsies was 100%.

CONCLUSIONS

Liquid-based cytology demonstrated better sensitivity and accuracy than conventional smears. Moreover, its diagnostic performance was close to that of forceps biopsies.

Endoscopic management of perihilar cholangiocarcinoma

Endoscopic management for perihilar cholangiocarcinoma (PHCC) is evolving toward more accurate diagnosis and safer drainage. In imaging, it is important to diagnose the entire lesion using multidetector-row computed tomography to determine resectability and optimal surgical planning, followed by local diagnosis using endoscopic retrograde cholangiopancreatography. Video peroral cholangioscopy and probe-based confocal laser endomicroscopy have been newly introduced as diagnostic imaging methods and are being applied clinically. In transpapillary forceps biopsy for PHCC diagnosis, the location in the bile duct (for mapping biopsy) and the number of biopsy samples should be determined depending on resectability, the morphological type, and future surgical planning. Preoperative drainage has shifted from percutaneous transhepatic biliary drainage to endoscopic nasobiliary drainage given the possibility of seeding metastasis. In addition, considering potential patient discomfort from a nasal tube, the usefulness of the placement of a plastic stent above the papilla (inside stent) as a bridging therapy for surgery has been reported. For drainage of unresectable PHCC, the improved prognosis due to advances in chemotherapy has necessitated a strategy that accounts for reintervention. Thus, in addition to uncovered self-expandable metallic stents (SEMS), exchangeable slim fully covered SEMS and inside stents have started to be used. In addition to the conventional transpapillary approach, an endoscopic ultrasonography-guided approach has been introduced, and a combination of both methods has also been proposed. To improve the quality of life and prognosis of PHCC patients, endoscopists need to understand and be able to use the various methods of endoscopic management for PHCC.

New technologies for indeterminate biliary strictures

An early and accurate diagnosis of biliary strictures yields optimal patient outcomes; however, endoscopic retrograde cholangiopancreatography (ERCP) with cytobrush/biopsy forceps has low sensitivity with a high number of false negatives. Various attempts to improve the accuracy of diagnosing indeterminate biliary strictures though ERCP-guided specimen acquisition have been proposed, such as with the use of fluorescence in situ hybridization, an endoscopic scraper, and the wire-grasping method, with modest to large improvements in sensitivity. Direct visualization of the biliary tree during peroral cholangioscopy has shown high sensitivity and specificity for the differentiation of neoplastic and non-neoplastic biliary lesions; however, there is no consensus on the visual characteristics of neoplastic lesions and moderate agreement between observers. Peroral cholangioscopy system (POCS)-guided specimen acquisition using forceps has shown inferior sensitivity compared to the visual characteristics; however, the specificity remains high. Optimal specimen processing with onsite evaluations and touch imprint cytology have been shown to improve the sensitivity and accurately diagnose nearly 90% of patients. In vivo evaluations of biliary strictures with probe-based confocal laser endomicroscopy have demonstrated high sensitivity with modest specificity for malignant biliary strictures. Optical computed tomography described reproductible criteria for malignancy detection in biliary strictures, increasing the sensitivity during ERCP evaluations. Differentiating benign causes from malignant causes of biliary strictures is a challenging task in clinical practice, with various concerns that still need to be addressed. Efforts should be made to define each diagnostic method's role in the evaluation of indeterminate biliary strictures.

Digital Cholangioscopic Interpretation: When North Meets the South

BACKGROUND

Digital single-operator cholangioscopy (DSOC) (SpyGlass DS™, Boston Scientific, MA, USA) allows for high-definition imaging of the biliary tree. The superior visualization has led to the development of two different sets of criteria to evaluate and classify indeterminate biliary strictures: the Monaco criteria and the criteria in Carlos Robles-Medranda's publication (CRM). Our objective was to assess the interrater agreement (IA) of DSOC interpretation for indeterminate biliary strictures using the two newly published criteria.

METHODS

Forty de-identified DSOC video recordings were sent to 15 interventional endoscopists with experience in cholangioscopy. They were asked to score the videos based on the presence of Monaco Classification criteria: stricture, lesion, mucosal changes, papillary projections, ulceration, white linear bands or rings, and vessels. Next, they scored the videos using CRM criteria: villous pattern, polypoid pattern, inflammatory pattern, flat pattern, ulcerate pattern and honeycomb pattern. The endoscopists then diagnosed the recordings as neoplastic or non-neoplastic based on the criteria. Intraclass correlation (ICC) analysis was done to evaluate interrater agreement for both criteria set and final diagnosis.

RESULTS

Recordings of 26 malignant lesions and 14 benign lesions were scored. The IA using both the Monaco criteria and CRM criteria ranged from poor to excellent (range 0.1-0.76) and (range 0.1-0.62), respectively. Within the Monaco criteria, IA was excellent for lesion (0.75) and fingerlike papillary projections (0.74); good for tortuous vessels (0.7), mucosal features (0.62), uniform papillary projections (0.53), and ulceration (0.58); and fair for white linear bands (0.4). Within the CRM criteria, the IA was good for villous pattern (0.62), flat pattern (0.62), and honeycomb pattern; fair for ulcerated pattern (0.56), polypoid pattern (0.52) and inflammatory pattern (0.54). The diagnostic IA using Monaco criteria was good (0.65), while the diagnostic IA using CRM was fair (0.58). The overall diagnostic accuracy using the Monaco classification was 61% and CRM criteria were 57%.

CONCLUSION

The IOA and accuracy rate of DSOC using visual criteria from both Monaco Criteria and CRM are similar. However, some criteria from both sets suffer from poor IA, thus affecting the overall diagnostic accuracy. More formal training and refinements in visual criteria with additional validation are needed to improve diagnostic accuracy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02166099.

Improving Diagnostic Yield in Indeterminate Biliary Strictures

Indeterminate biliary strictures are defined as a narrowing of the bile duct that cannot be differentiated as malignant or benign after performing cross-sectional imaging and an ERCP. Identifying the etiology of a bile duct stricture is the single most important step in determining whether a complex and potentially morbid surgical resection is warranted. Due to this diagnostic and therapeutic dilemma, new technologies, laboratory tests, and procedures are emerging to solve this problem.

Diagnostic power of DNA methylation markers suggestive of cholangiocarcinoma in ERCP-based brush cytology

BACKGROUND AND AIMS

Accurate differentiation between cholangiocarcinoma (CCA) and benign biliary stricture is of paramount importance. Biliary brush cytology is a simple and safe diagnostic approach that provides relatively high specificity; however, sensitivity is limited. Previous reports indicated the aberrations of DNA methylation in CCA. This study aimed to investigate the diagnostic performance of the methylation index (MI) of HOXA1 and NEUROG1 gene promoters in CCA.

METHODS

Patients with biliary stricture who underwent ERCP with brush cytology in Siriraj Hospital from September 2016 to December 2019 were prospectively enrolled. The MI of HOXA1 (MI_H) and MI of NEUROG1 (MI_N) were determined by quantitative methylation-specific polymerase chain reaction. The diagnostic power for CCA was tested for MI from both genes and serum carbohydrate antigen 19-9 (CA19-9).

RESULTS

Sixty-seven patients were included in the study; 41 patients had a final diagnosis of CCA, and 26 patients were determined to have a benign biliary stricture. The results showed that both MI_H and MI_N had higher sensitivity and accuracy (95.1% and 82.3% and 90.2% and 89.5%, respectively) than brush cytology (61.5% and 78.1%) and CA19-9 (69.4% and 77.8%). The combination of brush cytology, both methylation markers, and CA19-9 increased the sensitivity and accuracy to 97.4% and 91.0%. Methylation markers were positive in 5 of 6 patients with confirmed CCA whose cytology and CA19-9 were negative.

CONCLUSIONS

DNA methylation increased the sensitivity for the diagnosis of CCA; therefore, the use of DNA methylation is promising for diagnosis of CCA in patients with biliary strictures. A future validation study is warranted to assess its role in clinical practice. (Clinical trial registration number: NCT04568512.).

Biliary Strictures and Cholangiocarcinoma - Untangling a Diagnostic Conundrum

Cholangiocarcinoma is an uncommon and highly aggressive biliary tract malignancy with few manifestations until late disease stages. Diagnosis is currently achieved through a combination of clinical, biochemical, radiological and histological techniques. A number of reported cancer biomarkers have the potential to be incorporated into diagnostic pathways, but all lack sufficient sensitivity and specificity limiting their possible use in screening and early diagnosis. The limitations of standard serum markers such as CA19-9, CA125 and CEA have driven researchers to identify multiple novel biomarkers, yet their clinical translation has been slow with a general requirement for further validation in larger patient cohorts. We review recent advances in the diagnostic pathway for suspected CCA as well as emerging diagnostic biomarkers for early detection, with a particular focus on non-invasive approaches.

Next-Generation Biomarkers for Cholangiocarcinoma

Simple Summary

Early and non-invasive diagnosis of cholangiocarcinoma (CCA) is still challenging, thus largely contributing to the increased mortality rates observed worldwide. Consequently, several efforts have been made in order to report novel biomarkers for CCA, that would aid on diagnosis and also to predict prognosis and therapy response. We herein aim to provide an in-depth and critical revision on the next-generation biomarkers for CCA that have been recently proposed.

Abstract

The increasing mortality rates of cholangiocarcinoma (CCA) registered during the last decades are, at least in part, a result of the lack of accurate non-invasive biomarkers for early disease diagnosis, making the identification of patients who might benefit from potentially curative approaches (i.e., surgery) extremely challenging. The obscure CCA pathogenesis and associated etiological factors, as well as the lack of symptoms in patients with early tumor stages, highly compromises CCA identification and to predict tumor development in at-risk populations. Currently, CCA diagnosis is accomplished by the combination of clinical/biochemical features, radiological imaging and non-specific serum tumor biomarkers, although a tumor biopsy is still needed to confirm disease diagnosis. Furthermore, prognostic and predictive biomarkers are still lacking and urgently needed. During the recent years, high-throughput omics-based approaches have identified novel circulating biomarkers (diagnostic and prognostic) that might be included in large, international validation studies in the near future. In this review, we summarize and discuss the most recent advances in the field of biomarker discovery in CCA, providing new insights and future research directions.

Aspiration fluid cytology during single operator cholangioscopy with targeted biopsy to improves the diagnostic yield in indeterminate biliary strictures

INTRODUCTION

Sensitivities of various sampling methods to detect malignant biliary strictures remain suboptimal. Irrigation during digital single operator cholangioscopy (dSOC) is done routinely for visualization of the duct. The aim of this study was to evaluate improvement of the sensitivity for detecting malignant biliary strictures when adding aspiration fluid cytology (AFC) from the irrigated fluid during cholangioscopy to cholangioscopic biopsy (CBx).

METHODS

We conducted a retrospective analysis of patients at a tertiary medical center who underwent CBx for evaluation of their biliary strictures. We included patients who had aspiration of fluid from the bile duct after CBx and were sent for cytology from January 2017 to October 2017. Diagnosis was made on the basis of final pathology or follow-up over 9 months.

RESULTS

Fifty-six patients had CBx obtained, out of which 35 patients had AFC in conjunction. Twenty-two (62%) patients were male and the average age was 65 years. Considering atypical cells as benign, the sensitivity, specificity, positive and negative predictive values (PPV, NPV) for CBx were 62.5%, 100%, 100%, and 76% respectively. When CBx combined with AFC, the above statistics went up to 81.25%, 100%, 100%, and 86.36% respectively. When atypical cells were considered malignant, the sensitivity, specificity, PPV and NPV for CBx were 81.25%, 84.21%, 81.25%, 84.21% and increased to 93.75%, 78.94%, 78.94%, and 93.75% respectively after adding AFC results.

CONCLUSION

For patients with biliary stricture, addition of AFC dSOC guided biopsies, significantly improves the sensitivity for detecting malignancy.

Determining the Indeterminate Biliary Stricture: Cholangioscopy and Beyond

PURPOSE OF REVIEW

Indeterminate biliary strictures (IDBS) continue to be an area of frustration for clinicians. Standard endoscopic retrograde cholangiopancreatography (ERCP) with conventional brush cytology and/or forceps biopsy has a low sensitivity for distinguishing benign from malignant biliary strictures. A delay in diagnosis of malignancy has consequences for subsequent therapy or surgery. In this article, we review current and emerging technologies that may aid in this diagnostic dilemma.

RECENT FINDINGS

Several technologies have been utilized in IDBS to establish a diagnosis which include peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound with fine needle aspiration, intraductal ultrasound, optical coherence tomography, fluorescence in situ hybridization, next generation sequencing, integrated molecular pathology, and DNA-image cytometry. While cholangioscopy and confocal laser endomicroscopy have become standards of care in expert centers for the evaluation of patients with IDBS, there are several endoscopic and molecular modalities that may also aid in establishing a diagnosis. Further head-to-head prospective diagnostic studies as well as cost-efficacy studies are needed.

Cholangiocarcinoma in Patients with Primary Sclerosing Cholangitis (PSC): a Comprehensive Review

Cholangiocarcinoma (CCA) is the most common malignancy in patients with primary sclerosing cholangitis (PSC) and carries a high rate of mortality. Although the pathogenesis of CCA in PSC is largely unknown, inflammation-driven carcinogenesis concomitant with various genetic and epigenetic abnormalities are underlying factors. The majority of CCA cases develop from a dominant stricture (DS), which is defined as a stricture with a diameter < 1.5 mm in the common bile duct or < 1.0 mm in the hepatic duct. In PSC patients presenting with an abrupt aggravation of jaundice, pain, fatigue, pruritus, weight loss, or worsening liver biochemistries, CCA should be suspected and evaluated utilizing a variety of diagnostic modalities. However, early recognition of CCA in PSC remains a major challenge. Importantly, 30-50% of CCA in PSC patients are observed within the first year following the diagnosis of PSC followed by an annual incidence ranging from 0.5 to 1.5 per 100 persons, which is nearly 10 to 1000 times higher than that in the general population. Cumulative 5-year, 10-year, and lifetime incidences are 7%, 8-11%, and 9-20%, respectively. When PSC-associated CCA is diagnosed, most tumors are unresectable, and no effective medications are available. Given the poor therapeutic outcome, the surveillance and management of PSC patients who are at an increased risk of developing CCA are of importance. Such patients include older males with large-duct PSC and possibly concurrent ulcerative colitis. Thus, more attention should be paid to patients with these clinical features, in particular within the first year after PSC diagnosis. In contrast, CCA is less frequently observed in pediatric or female PSC patients or in those with small-duct PSC or concurrent Crohn's disease. Recently, new biomarkers such as antibodies to glycoprotein 2 have been found to be associated with an increased risk of developing CCA in PSC. Herein, we review the literature on the pathogenesis, incidence, clinical features, and risk factors, with a focus on various diagnostic modalities of PSC-associated CCA.

Endoscopic Ultrasound-Guided Fine Needle Aspiration and Endoscopic Retrograde Cholangiopancreatography-Based Tissue Sampling in Suspected Malignant Biliary Strictures: A Meta-Analysis of Same-Session Procedures

BACKGROUND/AIMS

The diagnosis of biliary strictures can be challenging. There are no systematic reviews studying same-session endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the diagnosis of biliary strictures.

METHODS

A systematic review was conducted on studies analyzing same-session EUS and ERCP for tissue diagnosis of suspected malignant biliary strictures. The primary outcome was the accuracy of each method individually compared to the two methods combined. The secondary outcome was the accuracy of each method in pancreatic and biliary etiologies. In the meta-analysis, we used Forest plots, summary receiver operating characteristic curves, and estimates of the area under the curve for intention-to-treat analysis.

RESULTS

Of the 12,132 articles identified, six were included, resulting in a total of 497 patients analyzed. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and accuracy of the association between the two methods were: 86%, 98%, 12.50, 0.17, and 96.5%, respectively. For the individual analysis, the sensitivity, specificity and accuracy of EUS-FNA were 76%, 100%, and 94.5%, respectively; for ERCP-based tissue sampling, the sensitivity, specificity, and accuracy were 58%, 98%, and 78.1%, respectively. For pancreatic lesions, EUS-FNA was superior to ERCP-based tissue sampling. However, for biliary lesions, both methods had similar sensitivities.

CONCLUSION

Same-session EUS-FNA and ERCP-based tissue sampling is superior to either method alone in the diagnosis of suspected malignant biliary strictures. Considering these results, combination sampling should be performed when possible.

Challenging biliary strictures: pathophysiological features, differential diagnosis, diagnostic algorithms, and new clinically relevant biomarkers - part 1

It is frequently challenging to make the correct diagnosis in patients with biliary strictures. This is particularly important as errors may have disastrous consequences. Benign-appearing strictures treated with stents may later be revealed to be malignant and unnecessary surgery for benign strictures carries a high morbidity rate. In the first part of the review, the essential information that clinicians need to know about diseases responsible for biliary strictures is presented, with a focus on the most recent data. Then, the characteristics and pitfalls of the methods used to make the diagnosis are summarized. These include serum biomarkers, imaging studies, and endoscopic modalities. As tissue diagnosis is the only 100% specific tool, it is described in detail, including techniques for tissue acquisition and their yields, how to prepare samples, and what to expect from the pathologist. Tricks to increase diagnostic yields are described. Clues are then presented for the differential diagnosis between primary and secondary sclerosing cholangitis, IgG4-related sclerosing cholangitis, cholangiocarcinoma, pancreatic cancer, autoimmune pancreatitis, and less frequent diseases. Finally, algorithms that will help to achieve the correct diagnosis are proposed.

Integrating next-generation sequencing to endoscopic retrograde cholangiopancreatography (ERCP)-obtained biliary specimens improves the detection and management of patients with malignant bile duct strictures

OBJECTIVE

Despite improvements in imaging, serum CA19-9 and pathological evaluation, differentiating between benign and malignant bile duct strictures remains a diagnostic conundrum. Recent developments in next-generation sequencing (NGS) have opened new opportunities for early detection and management of cancers but, to date, have not been rigorously applied to biliary specimens.

DESIGN

We prospectively evaluated a 28-gene NGS panel (BiliSeq) using endoscopic retrograde cholangiopancreatography-obtained biliary specimens from patients with bile duct strictures. The diagnostic performance of serum CA19-9, pathological evaluation and BiliSeq was assessed on 252 patients (57 trainings and 195 validations) with 346 biliary specimens.

RESULTS

The sensitivity and specificity of BiliSeq for malignant strictures was 73% and 100%, respectively. In comparison, an elevated serum CA19-9 and pathological evaluation had sensitivities of 76% and 48%, and specificities of 69% and 99%, respectively. The combination of BiliSeq and pathological evaluation increased the sensitivity to 83% and maintained a specificity of 99%. BiliSeq improved the sensitivity of pathological evaluation for malignancy from 35% to 77% for biliary brushings and from 52% to 83% for biliary biopsies. Among patients with primary sclerosing cholangitis (PSC), BiliSeq had an 83% sensitivity as compared with pathological evaluation with an 8% sensitivity. Therapeutically relevant genomic alterations were identified in 20 (8%) patients. Two patients with ERBB2-amplified cholangiocarcinoma received a trastuzumab-based regimen and had measurable clinicoradiographic response.

CONCLUSIONS

The combination of BiliSeq and pathological evaluation of biliary specimens increased the detection of malignant strictures, particularly in patients with PSC. Additionally, BiliSeq identified alterations that may stratify patients for specific anticancer therapies.

Cholangiocarcinoma: a site-specific update on the current state of surgical management and multi-modality therapy

Biliary tract cancers (BTC) are rare, heterogeneous malignancies that include cholangiocarcinoma and gallbladder cancer (GBC). Cholangiocarcinoma subtypes differ by anatomic location and molecular profile. Currently, resection with lymphadenectomy is the only curative treatment of locally advanced cholangiocarcinoma. Given the high risk of recurrence, multi-modality therapy spanning surgery, chemotherapy, and radiation therapy should be considered. Current data is discordant and there is limited prospective data to support an optimal treatment regimen, though recent studies have demonstrated the utility of adjuvant chemotherapy and chemoradiation in specific settings and patient populations. There is a potential role for neoadjuvant chemotherapy in patients with resectable disease or chemoradiation in select patients with unresectable, locally advanced disease. Randomized clinical trials are necessary to establish the effectiveness of therapies specific to disease sites, especially with the emerging role of immunotherapy and targeted therapy to actionable mutations.

Surgical Considerations of Hilar Cholangiocarcinoma

Cholangiocarcinoma is an aggressive malignancy of the extrahepatic bile ducts. Hilar lesions are most common. Patients present with obstructive jaundice and intrahepatic bile duct dilation. Cross-sectional imaging reveals local, regional, and distant extent of disease, with direct cholangiography providing tissue for diagnosis. The consensus of a multidisciplinary committee dictates treatment. Resection of the extrahepatic bile duct and ipsilateral hepatic lobe with or without vascular resection and transplantation after neoadjuvant protocol are options for curative treatment. The goal of surgery is to remove the tumor with negative margins. Patients with inoperable tumors or metastatic disease are best served with palliative chemoradiotherapy.

Diagnostic-therapeutic management of bile duct cancer

Biliary tract cancer, or cholangiocarcinoma, comprises a heterogeneous group of malignant tumors that can emerge at any part of the biliary tree. This group is the second most common type of primary liver cancer. Diagnosis is usually based on symptoms, which may be heterogeneous, and nonspecific biomarkers in serum and biopsy specimens, as well as on imaging techniques. Endoscopy-based diagnosis is essential, since it enables biopsy specimens to be taken. In addition, it can help with locoregional staging of distal tumors. Endoscopic retrograde cholangiopancreatography is a key technique for the evaluation and treatment of malignant biliary tumors. Correct staging of cholangiocarcinoma is essential in order to be able to determine the degree of resectability and assess the results of treatment. The tumor is staged based on the TNM classification of the American Joint Committee on Cancer. The approach will depend on the classification of the tumor. Thus, some patients with early-stage disease could benefit from surgery; complete surgical resection is the cornerstone of cure. However, only a minority of patients are diagnosed in the early stages and are suitable candidates for resection. In the subset of patients diagnosed with locally advanced or metastatic disease, chemotherapy has been used to improve outcome and to delay tumor progression. The approach to biliary tract tumors should be multidisciplinary, involving experienced endoscopists, oncologists, radiologists, and surgeons.

Anatomical, histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin-producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub-classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho-molecular groups can currently be discriminated. Large-duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2-fusions are typically seen in small-duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.

Practical Management of Indeterminate Biliary Strictures

Indeterminate biliary strictures pose a diagnostic and therapeutic challenge. Although underlying malignancy is a primary concern, biliary strictures may result from benign processes. An accurate diagnosis is paramount to define the treatment strategy and minimize morbidity. The limitations of traditional endoscopic retrograde cholangiopancreatography-based tissue acquisition with cytology brushings are well-documented. Endoscopic retrograde cholangiopancreatography is generally unable to determine a stricture's etiology. Complementary advanced endoscopic imaging and multimodal tissue acquisition have evolved. Careful consideration of the clinical presentation, location of the stricture, and interpretation of imaging constitute the most optimal approach for diagnosis and management.

Emerging Technologies for the Diagnosis of Perihilar Cholangiocarcinoma

The diagnosis of malignant biliary strictures remains problematic, especially in the perihilar region and in primary sclerosing cholangitis (PSC). Conventional cytology obtained during endoscopic retrograde cholangiography (ERC)-guided brushings of biliary strictures is suboptimal due to limited sensitivity, albeit it remains the gold standard with a high specificity. Emerging technologies are being developed and validated to address this pressing unmet patient need. Such technologies include enhanced visualization of the biliary tree by cholangioscopy, intraductal ultrasound, and confocal laser endomicroscopy. Conventional cytology can be aided by employing complementary and advanced cytologic techniques such as fluorescent in situ hybridization (FISH), and this technique should be widely adapted. Interrogation of bile and serum by examining extracellular vesicle number and cargo, and exploiting next-generation sequencing and proteomic technologies, is also being explored. Examination of circulating cell-free deoxyribonucleic acid (cfDNA) for differentially methylated regions is a promising test which is being rigorously validated. The special expertise required for these analyses has to date hampered their validation and adaptation. Herein, we will review these emerging technologies to inform the reader of the progress made and encourage further studies, as well as adaptation of validated approaches.