Modern diagnostic approaches to cholangiocarcinoma

Bile metabolites as diagnostic biomarkers for perihilar cholangiocarcinoma

It is difficult to directly obtain pathological diagnosis of perihilar cholangiocarcinoma (pCCA). Analysis of bile in the pCCA microenvironment, based on metabolomics and statistical methods, can help in clinical diagnosis. Clinical information, bile samples, blood liver function, blood CA199, CEA, and other indicators were collected from 33 patients with pCCA and 16 patients with gallstones. Bile samples were analyzed using untargeted metabolomics methods. A combination of multivariate and univariate analyses were used to screen for potential differential metabolites Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and differential metabolite remodeling, we explored changes in the pCCA pathway and potential therapeutic targets. There were significant differences in patient blood TBIL, ALT, AST, TBA, CA19-9, and CEA indices (p < 0.05, |log2(fc)| ≥ 1) between two groups. A significant correlation was found between these different indicators by Spearman's analysis. The clinical parameters were correlated with mass-to-charge ratios of 305 (Positive Ion Mode, POS) and 246 (Negative Ion Mode, NEG) in the metabolic group (|r| ≥ 0.7, P ≤ 10^-7). The result of this study indicated that bile untargeted metabolomics combined with statistical analysis techniques may be used for diagnose and treatment of pCCA.

Pathology of Cholangiocarcinomas

Cholangiocarcinomas (CCA) are heterogeneous tumors that arise from epithelial cells of the biliary tract. They represent the second primary liver malignancy, after hepatocellular carcinoma. Recent epidemiological data show an increased incidence of intrahepatic CCA without any identified causes. According to their location on the biliary tract, intrahepatic, perihilar (p) and distal (d) CCA can be individualized. Intrahepatic CCA (iCCA) are subdivided into small duct type iCCA and large duct type iCCA, according to the level or size of the biliary duct affected. These two subgroups are characterized by distinct risk factors, gross aspect, histopathological and molecular features, and therapeutic management. The role of biopsy in iCCA is to confirm the diagnosis and to eliminate various differential diagnostics, in particular, metastases. In p/d CCA, biopsy requires more invasive approaches, and tissue samples are difficult to obtain, leading to a high rate of false negatives. In this review, we will discuss the different classifications of CCA (anatomical and macroscopic). We will describe the various microscopic and phenotypic subtypes of CCA. Finally, we will deal with their mode of extension, the role of biopsy and pre-neoplastic lesions.

Gene mutational profile of BRCAness and clinical implication in predicting response to platinum-based chemotherapy in patients with intrahepatic cholangiocarcinoma

BACKGROUND AND AIMS

Biliary tract cancers are rare malignancies with a poor prognosis and scarce therapeutic strategies. The significance of BRCAness in this setting is already unknown.

METHOD

Tissue specimens of BTC patients treated with platinum-based chemotherapy have been analyzed through the FOUNDATIONPne assay.

RESULTS

72/150 (48%) BRCAness mutated and 78/150 (52.0%) wild type (WT) patients were included. The most commonly mutated genes in the BRCAness mutated group were: ARID1A (N = 32, 44%), CDKN2A (N = 23, 32%), KRAS/NRAS (N = 16, 22%), CDKN2B (N = 13, 18%), BRCA2 (N = 13, 18%), PBRM1 (N = 12, 17%), ATM (N = 11, 15%), FGFR2 (N = 10, 14%), TP53 (N = 8, 11%), IRS2 (N = 7, 10%), CREBBP (N = 7, 10%) (table 3, figure 1). At the univariate analysis BRCAness mutation was associated with longer median Progression Free Survival (mPFS) (HR 0.68; 95% CI 0.49-0.95; p = 0.0254); it was not associated with longer mOS but a trend toward a benefit in survival was found (HR 0.77; 95% CI 0.50-1.19; p = 0.2388). Patients with BRCAness mutation showed a higher percentage of disease control rate (77.8 vs 67.9; p = 0.04) compared to patients WT. Multivariate analysis confirmed BRCAness mutation (HR 0.66; 95% CI: 0.45-0.98; p = 0.0422) as independent favorable prognostic factors for PFS and a positive trend was found for OS (HR 0.84; 95% CI: 0.53-1.33; p = 0.3652).

CONCLUSION

BRCAness BTC patients showed a better PFS compared BRCAnessWT patients after exposure to platinum-based chemotherapy. Moreover, the OS curves' trend showed in our analysis suggests that BRCAness mutated patients could benefit from a maintenance therapy with PARPi.

Role of Ancillary Techniques in Biliary Cytopathology Specimens

Biliary brushing cytology has become the standard of practice for the investigation of strictures of the biliary and pancreatic duct systems. The methodology however has a limitation in that it has low diagnostic sensitivity when only cytologic evaluation is used. A number of testing methodologies have been applied to brushing specimens in an attempt to improve overall sensitivity without loss of specificity. These have included DNA ploidy analysis, immunocytochemistry, individual gene mutational analysis, fluorescence in-situ hybridization (FISH), and next generation sequencing (NGS). Currently, FISH coupled with routine cytology appears to be the method of choice for improving diagnostic sensitivity. NGS shows significant promise for improvement of diagnostic sensitivity.

A nomogram to predict overall survival for biliary tract cancer

Background

The aim of the study was to develop and validate a nomogram to predict overall survival (OS) in biliary tract cancer (BTC).

Patients and methods

Patients diagnosed with BTC between 2004 and 2014 were selected for the study from the Surveillance, Epidemiology, and End Results (SEER) database. All patients were randomly allocated to 2 sets, the training set (n = 8,869) and the validation set (n = 8,766), for the purposes of validation. The prognostic effects of each variable were examined using univariate and multivariate analyses. Cox regression models and a nomogram were developed based on significant prognostic factors. The predictive and discriminatory capacity of the nomogram was evaluated by Harrell’s concordance index (C-index) and calibration plots.

Results

Data of 17,635 patients with BTC were collected from the SEER database. Age; race; tumor site; tumor grade; T, N, and M stage; marital status; and therapy were associated with survival in the multivariate models. All these factors were integrated to construct the nomogram. The nomogram for predicting OS displayed better discrimination power than the tumor-node-metastasis (TNM) stage system 6th edition in the training set and validation set. The calibration curve indicated that the nomogram was able to accurately predict 3- and 5-year OS.

Conclusion

This predictive model has the potential to provide an individualized risk estimate of survival in patients with BTC.

Prognostic significance of neutrophil-to-lymphocyte ratio in biliary tract cancers: a systematic review and meta-analysis

Background

Inflammation was considered to perform crucial roles in the development and metastasis of malignancies. A heightened neutrophil-lymphocyte ratio has been described to be associated with detrimental survivals in different malignancies. Debate remains over the impact of heightened neutrophil-lymphocyte ratio on survivals in biliary tract cancer. The review evaluated the prognostic value of neutrophil-lymphocyte ratio in biliary tract cancer.

Methods

MEDLINE, the Cochrane Library, EMBASE, and the Chinese SinoMed were systematically searched for relevant articles. Associations between neutrophil-lymphocyte ratio and long-term outcomes were expressed as the hazard ratios and 95% confidence intervals. The odds ratio was utilized to assess the association between neutrophil-lymphocyte ratio and clinicopathological parameters.

Results

Fourteen studies consisting of 3217 patients were analyzed: 1278 (39.73%) in the high pretreatment neutrophil-lymphocyte ratio group and 1939 (60.27%) in the low pretreatment neutrophil-lymphocyte ratio one. The results proved that heightened pretreatment neutrophil-lymphocyte ratio was significantly associated with detrimental overall survival and relapse free survival for biliary tract cancer patients. In addition, elevated neutrophil-lymphocyte ratio was positively correlated with higher carbohydrate antigen 19-9 levels, advanced TNM staging and greater lymph node involvement.

Conclusion

This meta-analysis marked that an increased pretreatment neutrophil-lymphocyte ratio was significantly linked with detrimental long-term outcomes and clinicopathological parameters for patients with biliary tract cancer.

Survival rates are higher in married patients with biliary tract cancer: a population-based study

Marital status has been identified as a prognostic factor in multiple malignancies. In this study, we assessed the prognostic value of marital status in 24,035 patients from the Surveillance, Epidemiology, and End Results database diagnosed with biliary tract cancer (BTC) between 2004 and 2014. Widowed patients were more likely to be women, elderly (> 60 years), have gallbladder cancer, and have localized SEER Stage disease than all other patients. Marital status was identified as an independent prognostic factor in both univariate and multivariate analyses, and cause-specific survival (CSS) rates were higher in married patients than unmarried patients. In addition, CSS rates were higher in ampulla of Vater cancer patients than in gallbladder cancer or cholangiocarcinoma patients. Further analysis revealed that CSS rates were lowest in widowed patients at each TNM stage and for all tumor sites. These results suggest marital status is a prognostic factor for clinical outcomes in patients with BTC, and widowed patients are at greater risk of cancer-specific mortality.

Cholangiocarcinoma: New Insights

Cholangiocarcinoma is a malignant neoplasm originating from biliary epithelial cells. The incidence and mortality of this cancer are rising in the world. Currently, cholangiocarcinoma is accepted as a stem cell disease with many risk factors. Diagnosis is relatively simple but therapy is extremely difficult. Surgery is the mainstay of treatment for early stage patients. Endobiliary approaches, chemotherapy and radiotherapy are other therapeutic approaches.

Application of Fluorescence In Situ Hybridization (FISH) Technique for the Detection of Genetic Aberration in Medical Science

Fluorescence in situ hybridization (FISH) is a macromolecule recognition technique, which is considered as a new advent in the field of cytology. Initially, it was developed as a physical mapping tool to delineate genes within chromosomes. The accuracy and versatility of FISH were subsequently capitalized upon in biological and medical research. This visually appealing technique provides an intermediate degree of resolution between DNA analysis and chromosomal investigations. FISH consists of a hybridizing DNA probe, which can be labeled directly or indirectly. In the case of direct labeling, fluorescent nucleotides are used, while indirect labeling is incorporated with reporter molecules that are subsequently detected by fluorescent antibodies or other affinity molecules. FISH is applied to detect genetic abnormalities that include different characteristic gene fusions or the presence of an abnormal number of chromosomes in a cell or loss of a chromosomal region or a whole chromosome. It is also applied in different research applications, such as gene mapping or the identification of novel oncogenes. This article reviews the concept of FISH, its application, and its advantages in medical science. 

Overall Survival and Clinical Characteristics of BRCA-Associated Cholangiocarcinoma: A Multicenter Retrospective Study

BACKGROUND

Biliary tract malignancies, in particular cholangiocarcinomas (CCA), are rare tumors that carry a poor prognosis. BRCA2 mutation carriers have an increased risk of developing CCA with a reported relative risk of ∼5 according to the Breast Cancer Linkage Consortium. In addition to this risk, there are potential therapeutic implications in those harboring somatic and/or germline (GL) BRCA mutations. Therefore, it is important to define the clinical characteristics of GL/somatic BRCA1/2 variants in CCA patients.

MATERIALS AND METHODS

We performed a multicenter retrospective analysis of CCA patients diagnosed between January 2000 and December 2013 with GL or somatic variants in BRCA1/2 genes detected by GL mutations testing and/or by tumor next generation sequencing. Cases were identified from clinical databases at participating institutions. Data including demographics, clinical history, surgical procedures, and systemic chemotherapy or radiation were extracted from patients' records.

RESULTS

Overall, 18 cases were identified: 5 carriers of GL BRCA1/2 mutations (4 BRCA2; 1 BRCA1) and 13 harboring somatic variations (7 BRCA1; 6 BRCA2). Mean age at diagnosis was 60, SD ± 10 years (range 36-75 years), with male and female prevalence rates of 61.2% and 38.8%, respectively. Stage at diagnosis was I (n = 4), II (n = 3), III (n = 3), and IV (n = 8). Six patients had extrahepatic CCA and the rest intrahepatic CCA. Thirteen patients received platinum-based therapy and four were treated with poly ADP ribose polymerase inhibitors, of whom one experienced sustained disease response with a progression-free survival of 42.6 months. Median overall survival from diagnosis for patients with stage I/II in this study was 40.3 months (95% confidence interval [CI], 6.73-108.15) and with stages III/IV was 25 months (95% CI, 15.23-40.57).

CONCLUSION

BRCA-associated CCA is uncommon. This multicenter retrospective study provides a thorough clinical analysis of a BRCA-associated CCA cohort, which can serve as a benchmark for future development and design of expanded analyses and clinical trials.

IMPLICATIONS FOR PRACTICE

BRCA-associated CCA is uncommon but a very important subtype of hepatic malignancies, due to its rising prevalence. Better clinical characterization of this subtype might allow application of targeted therapy for CCA patients with germline or somatic mutations in BRCA1/2 genes, especially due to previously reported success of such therapies in other BRCA-associated malignancies. Thus this study, first of its kind, provides a basis for future multi-centered analyses in larger cohorts, as well as clinical trials. Additionally, this study emphasizes the importance of both germline and somatic genotyping for all CCA patients.

The Role of Endoscopy in the Diagnosis and Management of Cholangiocarcinoma

Cholangiocarcinomas (CCAs) are associated with poor overall survival, and majority of the tumors are unresectable at the time of diagnosis. Early diagnosis at a resectable stage is essential for improved outcomes. Noninvasive imaging plays an important role in evaluating patients with biliary obstruction, but is limited due to the lack of tissue sampling and in many cases due to the absence of a mass, especially for extrahepatic CCAs. Endoscopic diagnosis is needed in majority of patients with CCA and the diagnostic yield depends on the tumor location as well as the expertise and experience of the endoscopist. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound remain the most common endoscopic diagnostic tools although newer technologies including fluorescence in situ hybridization, single-operator cholangioscopy, confocal laser endomicroscopy, and intraductal ultrasound are being increasing used. Traditionally, the role of endoscopy has been mainly palliative and limited to biliary drainage in patients with obstructive jaundice, however, newer treatment options like photodynamic therapy and radiofrequency ablation have shown promise toward improved patient survival. Multidisciplinary approach that involves medical oncology, gastroenterology, radiology, and surgical oncology teams is imperative for improved outcomes. In this review, we will first review the diagnostic approach to CCAs including imaging and endoscopic methods followed by a discussion of different endoscopic techniques in management of patients after a diagnosis of CCA.

Whole slide image with image analysis of atypical bile duct brushing: Quantitative features predictive of malignancy

Background:

Whole slide images (WSIs) involve digitally capturing glass slides for microscopic computer-based viewing and these are amenable to quantitative image analysis. Bile duct (BD) brushing can show morphologic features that are categorized as indeterminate for malignancy. The study aims to evaluate quantitative morphologic features of atypical categories of BD brushing by WSI analysis for the identification of criteria predictive of malignancy.

Materials and Methods:

Over a 3-year period, BD brush specimens with indeterminate diagnostic categorization (atypical to suspicious) were subjected to WSI analysis. Ten well-visualized groups with morphologic atypical features were selected per case and had the quantitative analysis performed for group area, individual nuclear area, the number of nuclei per group, N: C ratio and nuclear size differential.

Results:

There were 28 cases identified with 17 atypical and 11 suspicious. The average nuclear area was 63.7 µm² for atypical and 80.1 µm² for suspicious (+difference 16.4 µm²; P = 0.002). The nuclear size differential was 69.7 µm² for atypical and 88.4 µm² for suspicious (+difference 18.8 µm²; P = 0.009). An average nuclear area >70 µm² had a 3.2 risk ratio for suspicious categorization.

Conclusion:

The quantitative criteria findings as measured by image analysis on WSI showed that cases categorized as suspicious had more nuclear size pleomorphism (+18.8 µm²) and larger nuclei (+16.4 µm²) than those categorized as atypical. WSI with morphologic image analysis can demonstrate quantitative statistically significant differences between atypical and suspicious BD brushings and provide objective criteria that support the diagnosis of carcinoma.

67 laminin receptor promotes the malignant potential of tumour cells up-regulating lysyl oxidase-like 2 expression in cholangiocarcinoma

BACKGROUND

67 laminin receptor (67LR) plays an important role in the invasion and metastasis of cholangiocarcinoma, but its mechanism remains unclear.

AIMS

We investigated the clinical significance of 67LR and its relation to lysyl oxidase-like 2 (LOXL2) in 67LR-mediated invasion and metastasis in cholangiocarcinoma.

METHODS

The clinical significance of 67LR and LOXL2 expression and the prognosis of patients were investigated in 73 cancerous and 32 paracancerous tissues by immunohistochemistry. The impact of LOXL2 on invasion, metastasis and 67LR expression was evaluated in cholangiocarcinoma cells by shRNA or expressed-plasmid transfection.

RESULTS

Expression of 67LR was recognized in 35.62% cholangiocarcinoma tissue, and none in paracancerous tissues. LOXL2 was positively correlated with expression of 67LR. Expression of 67LR or LOXL2 in cholangiocarcinomas was significantly associated with lymph node metastasis, differentiation and poor overall survival. Cox analysis showed that 67LR can act as an independent prognostic biomarker of prognosis in cholangiocarcinoma patients. Expression of LOXL2 decreased by knockdown of 67LR and increased by overexpression of 67LR in cholangiocarcinoma cells. Knockdown of LOXL2 reduced invasion and metastasis in vitro and in vivo.

CONCLUSION

67LR may regulate the expression of LOXL2 to promote invasion and metastasis in cholangiocarcinoma cells. It could be used as an independent prognostic marker in cholangiocarcinoma patients.

Stathmin1 regulates p27 expression, proliferation and drug resistance, resulting in poor clinical prognosis in cholangiocarcinoma

Patients with extrahepatic cholangiocarcinoma (EHCC) have a poor prognosis; postoperative survival depends on cancer progression and therapeutic resistance. The mechanism of EHCC progression needs to be clarified to identify ways to improve disease prognosis. Stathmin1 (STMN1) is a major cytosolic phosphoprotein that regulates microtubule dynamics and is associated with malignant phenotypes and chemoresistance in various cancers. Recently, STMN1 was reported to interact with p27, an inhibitor of cyclin-dependent kinase complexes. Eighty EHCC cases were studied using immunohistochemistry and clinical pathology to determine the correlation between STMN1 and p27 expression; RNA interference to analyze the function of STMN1 in an EHCC cell line was also used. Cytoplasmic STMN1 expression correlated with venous invasion (P = 0.0021) and nuclear p27 underexpression (P = 0.0011). Patients in the high-STMN1-expression group were associated with shorter recurrence-free survival and overall survival than those in the low-expression group. An in vitro protein-binding assay revealed that cytoplasmic STMN1 bound to p27 in the cytoplasm, but not in the nucleus of EHCC cells. Moreover, p27 accumulated in EHCC cells after STMN1 suppression. STMN1 knockdown inhibited proliferation and increased the sensitivity of EHCC cells to paclitaxel. STMN1 contributes to a poor prognosis and cancer progression in EHCC patients. Understanding the regulation of p27 by STMN1 could provide new insights for overcoming therapeutic resistance in EHCC.

Novel diagnostic and prognostic biomarkers in biliary tract cancer

INTRODUCTION

The worldwide incidence of biliary tract carcinoma (BTC, tumours of the bile ducts and gall-bladder) continues to rise, with the only potentially curative treatment remaining surgical resection or transplantation, possible in only a minority of patients. Late presentation and a paucity of effective treatments mandate the development of techniques for early lesion detection.

AREAS COVERED

This article reviews currently available biomarkers for the diagnosis and prognosis of BTC, as well as recently published studies describing novel serum, bile and urinary biomarkers.

EXPERT OPINION

The incorporation of novel analysis techniques, such as digital image analysis and fluorescence in situ hybridization, into existing management algorithms enhances the accuracy of brush cytology taken at the time of therapeutic endoscopy. However, a key goal is the discovery of reliable non-invasive biomarkers with high sensitivity and specificity. Recent advances in gene sequencing and expression, clonal evolution and tumour heterogeneity in other cancers should advance understanding of BTC tumour biology and facilitate biomarker discovery.

New routes to targeted therapy of intrahepatic cholangiocarcinomas revealed by next-generation sequencing

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a subtype of primary liver cancer that is rarely curable by surgery and is rapidly increasing in incidence. Relapsed ICC has a poor prognosis, and current systemic nontargeted therapies are commonly extrapolated from those used in other gastrointestinal malignancies. We hypothesized that genomic profiling of clinical ICC samples would identify genomic alterations that are linked to targeted therapies and that could facilitate a personalized approach to therapy.

METHODS

DNA sequencing of hybridization-captured libraries was performed for 3,320 exons of 182 cancer-related genes and 36 introns of 14 genes frequently rearranged in cancer. Sample DNA was isolated from 40 μm of 28 formalin-fixed paraffin-embedded ICC specimens and sequenced to high coverage.

RESULTS

The most commonly observed alterations were within ARID1A (36%), IDH1/2 (36%), and TP53 (36%) as well as amplification of MCL1 (21%). Twenty cases (71%) harbored at least one potentially actionable alteration, including FGFR2 (14%), KRAS (11%), PTEN (11%), CDKN2A (7%), CDK6 (7%), ERBB3 (7%), MET (7%), NRAS (7%), BRCA1 (4%), BRCA2 (4%), NF1 (4%), PIK3CA (4%), PTCH1 (4%), and TSC1 (4%). Four (14%) of the ICC cases featured novel gene fusions involving the tyrosine kinases FGFR2 and NTRK1 (FGFR2-KIAA1598, FGFR2-BICC1, FGFR2-TACC3, and RABGAP1L-NTRK1).

CONCLUSION

Two thirds of patients in this study harbored genomic alterations that are associated with targeted therapies and that have the potential to personalize therapy selection for to individual patients.

The Glasgow Prognostic Score accurately predicts survival in patients with biliary tract cancer not indicated for surgical resection

The Glasgow Prognostic Score (GPS) and neutrophil to lymphocyte ratio (NLR) are associated with the survival in patients with various types of malignancy. The aim of this study was to investigate the prognostic value of the GPS and NLR in patients with biliary tract cancer (BTC) undergoing palliative chemotherapy or best supportive care (BSC). Fifty-two patients with newly diagnosed BTC were retrospectively evaluated. We investigated the correlation between the GPS, NLR, and the overall survival rates. The area under the receiver operating characteristics curve (AUC) was calculated to compare the predictive ability of each score. Both the univariate and multivariate analyses were performed to identify clinicopathological variables associated with the overall survival. There were significant differences between the GPS groups regarding the neutrophil levels (p < 0.0001), Hb (p = 0.024), Alb (p < 0.0001) and CRP (p < 0.0001). A significant difference in the overall survival was found between the groups stratified based on the GPS, NLR (p < 0.001). The GPS had a higher AUC value (0.905) in comparison to the NLR (0.648). In the multivariate analysis, the sex (p = 0.002), CA19-9 (p < 0.0001) and the GPS (p < 0.0001) were found to be independently associated with the overall survival. Our results demonstrate that the GPS is an independent marker of the prognosis in patients with BTC undergoing palliative chemotherapy or BSC, and is superior to the NLR in terms of its prognostic ability.

Forkhead box protein C2 contributes to invasion and metastasis of extrahepatic cholangiocarcinoma, resulting in a poor prognosis

Extrahepatic cholangiocarcinoma (EHCC) is a cancer with a poor prognosis, and the postoperative survival of patients depends on the existence of invasion and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important step in EHCC invasion and metastasis. Forkhead box protein C2 (FOXC2) is a transcription factor that has been reported to induce the EMT. Therefore we examined the correlation between FOXC2 expression and clinical pathological factors, and analysed the function of FOXC2. The expression of FOXC2 in 77 EHCC cases was investigated by immunohistochemical staining, and the relationship between FOXC2 expression and clinicopathological factor was assessed. Knockdown by small interfering RNA (siRNA) was performed to determine the roles of FOXC2 in EHCC cell line. FOXC2 expression correlated with lymph node metastasis (P = 0.0205). Patients in the high FOXC2 expression group had a poorer prognosis than the patients in the low FOXC2 expression group. Moreover, FOXC2 knockdown inhibited cell motility and invasion, and decreased the expression of EMT markers (N-cadherin, and matrix metalloproteinase (MMP) -2) and Angiopietin-2 (Ang-2). The EMT inducer FOXC2 contributes to a poor prognosis and cancer progression. FOXC2 may be a promising molecular target for regulating EHCC metastasis.

An extended fluorescence in situ hybridization approach for the cytogenetic study of cholangiocarcinoma on endoscopic retrograde cholangiopancreatography brushing cytology preparations

The cytological diagnosis of cholangiocarcinoma has been significantly aided by applying a 4-probe fluorescence in situ hybridization system on endoscopic retrograde cholangiopancreatography brushing smears, aiming mainly at the detection of hyperdiploidy. However, this approach adds little to our understanding of the genetic background of the disease. With the prospect of obtaining additional data on chromosomal aberrations, we have extended the fluorescence in situ hybridization study, with the application of 4 independent 2-probe systems in 35 patients with documented cholangiocarcinoma. Fluorescence in situ hybridization assays were performed on endoscopic retrograde cholangiopancreatography brushing smears, with probes for the 7q31, 11q13 (CCND1), 17p53 (TP53), and 9p21 (INK4 locus) bands, together with the respective centromeric probe. Hyperdiploidy, involving at least 2 of the 4 chromosomes targeted, was found in 31 patients. 17p13 deletion was detected in 3, and 9p21 deletion, in 5 of the hyperdiploid cases, with the 2 aberrations concurrent in 1. CCND1 amplification was found in 1 case as the sole abnormality and in another together with hyperdiploidy, but in apparently unrelated clones. This work indicates that interphase fluorescence in situ hybridization is a practical and useful tool for the cytogenetic study of cholangiocarcinoma on endoscopic retrograde cholangiopancreatography brushing smears, which is often the only available tissue specimen of the tumor. Apart from hyperdiploidy, it provides additional data on the genetic profile of cholangiocarcinoma, especially regarding structural chromosomal aberrations and clonal diversity. This line of investigation may prove useful in the delineation of oncogenesis and the interpretation of the diverse clinical features of the disease.