DNA abnormalities as marker of risk for progression of Barrett's esophagus to adenocarcinoma: image cytometric DNA analysis in formalin-fixed tissues

Significance of Crypt Atypia in Barrett's Esophagus: A Clinical, Molecular, and Outcome Study

BACKGROUND & AIMS

The aim of this study was to characterize baseline morphologic features of crypts in nondysplastic Barrett's esophagus and correlate them with DNA content abnormalities and risk of progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC).

METHODS

The morphologic features of nondysplastic crypts in baseline biopsy specimens from 212 BE patients (2956 biopsy specimens) were graded histologically using a 4-point scale (crypt atypia levels, 0-3). DNA content abnormalities were detected using flow cytometry.

RESULTS

In patients who had dysplasia in their baseline biopsy specimens, dysplasia was associated significantly with increasing grades of crypt atypia in the background nondysplastic Barrett's esophagus (P < .001). In a subset of patients without dysplasia at baseline (N = 149), a higher grade of crypt atypia was associated with longer Barrett's esophagus segment length (5.5 vs 3.3 cm; P = .0095), and a higher percentage of cells with 4N DNA content (3.67 ± 1.27 vs 2.93 ± 1.22; P = .018). Crypt atypia was associated with the development of any neoplasia (low-grade dysplasia and HGD/EAC). Although no significant association was noted between the grade of crypt atypia and increased 4N, aneuploidy, or progression to HGD/EAC, only patients with grade 2 or 3 crypt atypia showed increased 4N, aneuploidy, or progression to HGD/EAC.

CONCLUSIONS

Patients with Barrett's esophagus likely develop dysplasia via a progressive increase in the level of crypt atypia before the onset of dysplasia, and these changes may reflect some alteration of DNA content.

DNA flow cytometry for detection of genomic instability as a cancer precursor in the gastrointestinal tract

One of the earliest applications of flow cytometry was the measurement of DNA content in cells. This method is based on the ability to stain DNA in a stoichiometric manner (i.e., the amount of stain is directly proportional to the amount of DNA within the cell). For more than 40years, a number of studies have consistently demonstrated the utility of DNA flow cytometry as a potential diagnostic and/or prognostic tool in patients with most epithelial tumors, including pre-invasive lesions (such as dysplasia) in the gastrointestinal tract. However, its availability as a clinical test has been limited to few medical centers due to the requirement for fresh tissue in earlier studies and perceived technical demands. However, more recent studies have successfully utilized formalin-fixed paraffin-embedded (FFPE) tissue to generate high-quality DNA content histograms, demonstrating the feasibility of this methodology. This review summarizes step-by-step methods on how to perform DNA flow cytometry using FFPE tissue and analyze DNA content histograms based on the published consensus guidelines in order to assist in the diagnosis and/or risk stratification of many different epithelial tumors, with particular emphasis on dysplasia associated with Barrett's esophagus and inflammatory bowel disease.

Barrett's esophagus: The pathomorphological and molecular genetic keystones of neoplastic progression

Barrett's esophagus is a widespread chronically progressing disease of heterogeneous nature. A life threatening complication of this condition is neoplastic transformation, which is often overlooked due to lack of standardized approaches in diagnosis, preventative measures and treatment. In this essay, we aim to stratify existing data to show specific associations between neoplastic transformation and the underlying processes which predate cancerous transition. We discuss pathomorphological, genetic, epigenetic, molecular and immunohistochemical methods related to neoplasia detection on the basis of Barrett's esophagus. Our review sheds light on pathways of such neoplastic progression in the distal esophagus, providing valuable insight into progression assessment, preventative targets and treatment modalities. Our results suggest that molecular, genetic and epigenetic alterations in the esophagus arise earlier than cancerous transformation, meaning the discussed targets can help form preventative strategies in at-risk patient groups.

A narrative review of Barrett's esophagus in 2020, molecular and clinical update

Barrett’s esophagus (BE) is a condition resulting from an acquired metaplastic epithelial change in the esophagus in response to gastroesophageal reflux. BE is the only known precursor lesion to esophageal adenocarcinoma, and can progress from non-dysplastic BE (NDBE) to low grade dysplasia (LGD) and high grade dysplasia (HGD), and ultimately invasive carcinoma. Although the risk of developing esophageal adenocarcinoma (EAC) in NBDE is less than 0.5% per year, there has been a rising incidence of EAC in Western countries, which continue to drive efforts to optimize screening and surveillance methods. The current gold standard for diagnosis is esophagogastroduodenoscopy (EGD), and there has been significant interest in alternative, minimally invasive methods for screening which would be more readily accessible in the primary care setting. Surveillance endoscopy in 3–5 years is recommended for NDBE given the low progression to EAC. The mainstay of treatment for LGD and HGD is endoscopic eradication therapy (EET). Visible lesions are treated with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Radiofrequency ablation (RFA) is considered first line therapy for flat dysplastic BE and cryotherapy has shown promising results as an alternate form of treatment for of dysplasia. The molecular progression of BE to EAC is a complex process involving multiple pathways involving genetic and epigenetic modifications. Genomic studies have further led to the understanding of the complex molecular landscape that occurs early and late in the disease process. Promising biomarker panels have been investigated to help with the diagnosis of BE as well as aid in the risk stratification of BE during surveillance. In addition, clinical prediction models have been developed to categorize BE patients in low, intermediate, and high risk for progression to HGD and EAC. Further clinical and translational research is needed to help refine markers and techniques in diagnosis, screening, and surveillance.

Diagnostic Utility of Cytology in Assessment of Ploidy Status in Potentially Malignant Oral Disorders

INTRODUCTION

Oral leukoplakia, the most common potentially malignant oral disorder (PMOD) may progress to oral squamous cell carcinoma (OSCC). Although, the current standard of care for assessing its malignant potential remains histological examination and assessing the severity of dysplasia, DNA ploidy analysis has been suggested as a surrogate marker to predict the behaviour of PMODs.

OBJECTIVES

To detect aneuploidy and to correlate ploidy status with different grades of dysplasia in both tissue and cytology samples to predict the behaviour of these potentially malignant disorders and to assess the diagnostic utility of cytology samples for ploidy analysis.

METHODOLOGY

After obtaining ethical clearance and consent, tissue and cytology samples of leukoplakia were collected and grouped based on the dysplastic findings into low-risk (n=20) and high-risk (n=20). DNA ploidy analysis was done using high resolution flow cytometry and its diagnostic utility was assessed.

RESULTS

Diagnostic utility was expressed in terms of sensitivity, specificity, PPV and NPV. On comparing the ploidy status of individual cases between tissue and cytology samples, cytology was able to accurately determine the ploidy status in majority of the cases. In the low-risk group, cytology had a sensitivity and specificity of 100% and a PPV and NPV of 100% with an overall diagnostic accuracy of 100%. Among the high-risk group, cytology had a sensitivity of 80% and specificity of 100% with a PPV of 100% and NPV of 83.33% and had an overall diagnostic accuracy of 90%. Combining both groups together, it had a sensitivity of 85.71% and specificity of 100% with a PPV of 100% and NPV of 92.31% and had an overall diagnostic accuracy of 94.74%.

CONCLUSION

Overall, this study showed a positive correlation between cytology and tissue samples and ploidy and grade of dysplasia and cytology proved to be a simple and efficient with a reasonable diagnostic value.

Biomarkers for Barrett's esophagus - a contemporary review

INTRODUCTION

Esophageal adenocarcinoma (EAC) has a poor 5-year survival rate (10%-18%), and incidence has increased dramatically in the past three decades. Barrett's esophagus (BE) is the precursor lesion to EAC and is the replacement of the normally squamous lined esophagus with columnar cells that develop an intestinal phenotype characterized by the presence of goblet cells. Given the known precursor state, EAC is amenable to screening and surveillance strategies (analogous to colon cancer). However, unlike from colon cancer screening, BE poses challenges that make effective screening difficult. Robust and concerted effort is under way to find biomarkers of BE. Areas covered: This review summarizes current known biomarkers for BE. These include dysplasia, genomic markers, and gene expression alterations that occur early in the dysplasia/carcinoma sequence. Expert commentary: Despite the tremendous breadth of work in studying molecular advances, the ideal biomarker for BE has not yet been discerned. This review comments on innovations in the field of BE research that combine state-of-the-art molecular advances with simple technologies.

Diagnosis and risk stratification of Barrett's dysplasia by flow cytometric DNA analysis of paraffin-embedded tissue

OBJECTIVE

The diagnosis of dysplasia in Barrett's oesophagus (BO) can be challenging, and reliable ancillary techniques are not available. This study examines if DNA content abnormality detected by flow cytometry can serve as a diagnostic marker of dysplasia and facilitate risk stratification of low-grade dysplasia (LGD) and indefinite for dysplasia (IND) patients using formalin-fixed paraffin-embedded (FFPE) BO samples with varying degrees of dysplasia.

DESIGN

DNA flow cytometry was performed on 80 FFPE BO samples with high-grade dysplasia (HGD), 38 LGD, 21 IND and 14 negative for dysplasia (ND). Three to four 60-micron thick sections were cut from each tissue block, and the area of interest was manually dissected.

RESULTS

DNA content abnormality was identified in 76 HGD (95%), 8 LGD (21.1%), 2 IND (9.5%) and 0 ND samples. As a diagnostic marker of HGD, the estimated sensitivity and specificity of DNA content abnormality were 95% and 85%, respectively. For patients with DNA content abnormality detected at baseline LGD or IND, the univariate HRs for subsequent detection of HGD or oesophageal adenocarcinoma (OAC) were 7.0 and 20.0, respectively (p =<0.001).

CONCLUSIONS

This study demonstrates the promise of DNA flow cytometry using FFPE tissue in the diagnosis and risk stratification of dysplasia in BO. The presence of DNA content abnormality correlates with increasing levels of dysplasia, as 95% of HGD samples showed DNA content abnormality. DNA flow cytometry also identifies a subset of patients with LGD and IND who are at higher risk for subsequent detection of HGD or OAC.

Meta-analysis of biomarkers predicting risk of malignant progression in Barrett's oesophagus

BACKGROUND

Barrett's oesophagus is a precursor to the development of oesophageal adenocarcinoma. This study sought to clarify the role of genetic, chromosomal and proliferation biomarkers that have been the subjects of multiple studies through meta-analysis.

METHODS

MEDLINE, Embase, PubMed and the Cochrane Library were searched for clinical studies assessing the value of p53, p16, Ki-67 and DNA content abnormalities in Barrett's oesophagus. The main outcome measure was the risk of development of high-grade dysplasia (HGD) or oesophageal adenocarcinoma.

RESULTS

Some 102 studies, with 12 353 samples, were identified. Mutation (diagnostic odds ratio (DOR) 10·91, sensitivity 47 per cent, specificity 92 per cent, positive likelihood ratio (PLR) 4·71, negative likelihood ratio (NLR) 0·65, area under the curve (AUC) 0·792) and loss (DOR 16·16, sensitivity 31 per cent, specificity 98 per cent, PLR 6·66, NLR 0·41, AUC 0·923) of p53 were found to be superior to the other p53 abnormalities (loss of heterozygosity (LOH) and overexpression). Ki-67 had high sensitivity in identifying high-risk patients (DOR 5·54, sensitivity 82 per cent, specificity 48 per cent, PLR 1·59, NLR 0·42, AUC 0·761). Aneuploidy (DOR 12·08, sensitivity 53 per cent, specificity 87 per cent, PLR 4·26, NLR 0·42, AUC 0·846), tetraploidy (DOR 5·87, sensitivity 46 per cent, specificity 85 per cent, PLR 3·47, NLR 0·65, AUC 0·793) and loss of Y chromosome (DOR 9·23, sensitivity 68 per cent, specificity 80 per cent, PLR 2·67, NLR 0·49, AUC 0·807) also predicted malignant development, but p16 aberrations (hypermethylation, LOH, mutation and loss) failed to demonstrate any advantage over the other biomarkers studied.

CONCLUSION

Loss and mutation of p53, and raised level of Ki-67 predicted malignant progression in Barrett's oesophagus.

Genetic Biomarkers of Barrett's Esophagus Susceptibility and Progression to Dysplasia and Cancer: A Systematic Review and Meta-Analysis

Barrett's esophagus (BE) is a common and important precursor lesion of esophageal adenocarcinoma (EAC). A third of patients with BE are asymptomatic, and our ability to predict the risk of progression of metaplasia to dysplasia and EAC (and therefore guide management) is limited. There is an urgent need for clinically useful biomarkers of susceptibility to both BE and risk of subsequent progression. This study aims to systematically identify, review, and meta-analyze genetic biomarkers reported to predict both. A systematic review of the PubMed and EMBASE databases was performed in May 2014. Study and evidence quality were appraised using the revised American Society of Clinical Oncology guidelines, and modified Recommendations for Tumor Marker Scores. Meta-analysis was performed for all markers assessed by more than one study. A total of 251 full-text articles were reviewed; 52 were included. A total of 33 germline markers of susceptibility were identified (level of evidence II-III); 17 were included. Five somatic markers of progression were identified; meta-analysis demonstrated significant associations for chromosomal instability (level of evidence II). One somatic marker of progression/relapse following photodynamic therapy was identified. However, a number of failings of methodology and reporting were identified. This is the first systematic review and meta-analysis to evaluate genetic biomarkers of BE susceptibility and risk of progression. While a number of limitations of study quality temper the utility of those markers identified, some-in particular, those identified by genome-wide association studies, and chromosomal instability for progression-appear plausible, although robust validation is required.

TissueCypher(™): A systems biology approach to anatomic pathology

Background:

Current histologic methods for diagnosis are limited by intra- and inter-observer variability. Immunohistochemistry (IHC) methods are frequently used to assess biomarkers to aid diagnoses, however, IHC staining is variable and nonlinear and the manual interpretation is subjective. Furthermore, the biomarkers assessed clinically are typically biomarkers of epithelial cell processes. Tumors and premalignant tissues are not composed only of epithelial cells but are interacting systems of multiple cell types, including various stromal cell types that are involved in cancer development. The complex network of the tissue system highlights the need for a systems biology approach to anatomic pathology, in which quantification of system processes is combined with informatics tools to produce actionable scores to aid clinical decision-making.

Aims:

Here, we describe a quantitative, multiplexed biomarker imaging approach termed TissueCypher™ that applies systems biology to anatomic pathology. Applications of TissueCypher™ in understanding the tissue system of Barrett's esophagus (BE) and the potential use as an adjunctive tool in the diagnosis of BE are described.

Patients and Methods:

The TissueCypher™ Image Analysis Platform was used to assess 14 epithelial and stromal biomarkers with known diagnostic significance in BE in a set of BE biopsies with nondysplastic BE with reactive atypia (RA, n = 22) and Barrett's with high-grade dysplasia (HGD, n = 17). Biomarker and morphology features were extracted and evaluated in the confirmed BE HGD cases versus the nondysplastic BE cases with RA.

Results:

Multiple image analysis features derived from epithelial and stromal biomarkers, including immune biomarkers and morphology, showed significant differences between HGD and RA.

Conclusions:

The assessment of epithelial cell abnormalities combined with an assessment of cellular changes in the lamina propria may serve as an adjunct to conventional pathology in the assessment of BE.

Digital pathology and image analysis in tissue biomarker research

Digital pathology and the adoption of image analysis have grown rapidly in the last few years. This is largely due to the implementation of whole slide scanning, advances in software and computer processing capacity and the increasing importance of tissue-based research for biomarker discovery and stratified medicine. This review sets out the key application areas for digital pathology and image analysis, with a particular focus on research and biomarker discovery. A variety of image analysis applications are reviewed including nuclear morphometry and tissue architecture analysis, but with emphasis on immunohistochemistry and fluorescence analysis of tissue biomarkers. Digital pathology and image analysis have important roles across the drug/companion diagnostic development pipeline including biobanking, molecular pathology, tissue microarray analysis, molecular profiling of tissue and these important developments are reviewed. Underpinning all of these important developments is the need for high quality tissue samples and the impact of pre-analytical variables on tissue research is discussed. This requirement is combined with practical advice on setting up and running a digital pathology laboratory. Finally, we discuss the need to integrate digital image analysis data with epidemiological, clinical and genomic data in order to fully understand the relationship between genotype and phenotype and to drive discovery and the delivery of personalized medicine.

Three-dimensional DNA image cytometry by optical projection tomographic microscopy for early cancer diagnosis

Aneuploidy is typically assessed by flow cytometry (FCM) and image cytometry (ICM). We used optical projection tomographic microscopy (OPTM) for assessing cellular DNA content using absorption and fluorescence stains. OPTM combines some of the attributes of both FCM and ICM and generates isometric high-resolution three-dimensional (3-D) images of single cells. Although the depth of field of the microscope objective was in the submicron range, it was extended by scanning the objective's focal plane. The extended depth of field image is similar to a projection in a conventional x-ray computed tomography. These projections were later reconstructed using computed tomography methods to form a 3-D image. We also present an automated method for 3-D nuclear segmentation. Nuclei of chicken, trout, and triploid trout erythrocyte were used to calibrate OPTM. Ratios of integrated optical densities extracted from 50 images of each standard were compared to ratios of DNA indices from FCM. A comparison of mean square errors with thionin, hematoxylin, Feulgen, and SYTOX green was done. Feulgen technique was preferred as it showed highest stoichiometry, least variance, and preserved nuclear morphology in 3-D. The addition of this quantitative biomarker could further strengthen existing classifiers and improve early diagnosis of cancer using 3-D microscopy.

The use of imaging and biomarkers in diagnosing Barrett's esophagus and predicting the risk of neoplastic progression

Long-standing gastroesophageal reflux disease can result in transformation of the normal squamous lining of the esophagus into columnar epithelium (with goblet cells). This condition, Barrett's esophagus (BE), is considered a risk factor for esophageal cancer (EAC) and may be the cause of the increased incidence of EAC over the last few decades. Currently, endoscopy with biopsies revealing dysplasia is the best predictor for neoplastic progression in patients with BE. However, the use of more sophisticated imaging techniques and biomarkers with or without histological assessment may be helpful in more accurate prediction of malignant transformation in these patients. New approaches to the evaluation of BE such as epigenetics, miRNA analysis, detection of DNA content abnormalities and loss of heterozygosity have great potential to shed light on the complex gastroesophageal reflux disease -BE-EAC sequence.

Quantification of DNA in simple eukaryotic cells using Fourier transform infrared spectroscopy

A technique capable of detecting and monitoring nucleic acid concentration offers potential in diagnosing cancer and further developing an understanding of the biochemistry of disease. The application of Fourier transform infrared (FTIR) spectroscopy has previously been hindered by the supposed non-Beer-Lambert absorption behavior of DNA in intact cells making elucidation of the DNA bands difficult. We use known composition DNA/hemoglobin standards to successfully estimate the DNA content in avian erythrocyte nuclei (44.2%) and intact erythrocytes (12.8%). Furthermore we demonstrate that the absorption of cellular DNA does follow the Beer-Lambert Law and highlights the role of conformation and hydration in FTIR spectroscopy of biological samples.

Molecular biomarkers in esophageal, gastric, and colorectal adenocarcinoma

Cancers of the esophagus, stomach and colon contribute to a major health burden worldwide and over 20% of all cancer deaths. Biomarkers that should indicate pathogenic process and are measureable in an objective manner for these tumors are rare and not established in the clinical setting. In general biomarkers can be very useful for cancer management as they can improve clinical decision-making regarding diagnosis, surveillance, and therapy. Biomarkers can be different types of molecular entities (such as DNA, RNA or proteins), which can be detected, in different tissues or body fluids. However, more important is the type of biomarker itself, which allows diagnostic, prognostic or predictive analyses for different clinical problems. This review aims to systematically summarize the recent findings of genetic and epigenetic markers for gastrointestinal tumors within the last decade. While many biomarkers seem to be very promising, especially if used as panels, further development is urgently needed to address practical considerations of biomarkers in cancer treatment.

Early diagnostic biomarkers for esophageal adenocarcinoma--the current state of play

Esophageal adenocarcinoma (EAC) is one of the two most common types of esophageal cancer with alarming increase in incidence and very poor prognosis. Aiming to detect EAC early, currently high-risk patients are monitored using an endoscopic-biopsy approach. However, this approach is prone to sampling error and interobserver variability. Diagnostic tissue biomarkers related to genomic and cell-cycle abnormalities have shown promising results, although with current technology these tests are difficult to implement in the screening of high-risk patients for early neoplastic changes. Differential miRNA profiles and aberrant protein glycosylation in tissue samples have been reported to improve performance of existing tissue-based diagnostic biomarkers. In contrast to tissue biomarkers, circulating biomarkers are more amenable to population-screening strategies, due to the ease and low cost of testing. Studies have already shown altered circulating glycans and DNA methylation in BE/EAC, whereas disease-associated changes in circulating miRNA remain to be determined. Future research should focus on identification and validation of these circulating biomarkers in large-scale trials to develop in vitro diagnostic tools to screen population at risk for EAC development.

GERD-Barrett-Adenocarcinoma: Do We Have Suitable Prognostic and Predictive Molecular Markers?

Due to unfavorable lifestyle habits (unhealthy diet and tobacco abuse) the incidence of gastroesophageal reflux disease (GERD) in western countries is increasing. The GERD-Barrett-Adenocarcinoma sequence currently lacks well-defined diagnostic, progressive, predictive, and prognostic biomarkers (i) providing an appropriate screening method identifying the presence of the disease, (ii) estimating the risk of evolving cancer, that is, the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC), (iii) predicting the response to therapy, and (iv) indicating an overall survival—prognosis for EAC patients. Based on histomorphological findings, detailed screening and therapeutic guidelines have been elaborated, although epidemiological studies could not support the postulated increasing progression rates of GERD to BE and EAC. Additionally, proposed predictive and prognostic markers are rather heterogeneous by nature, lack substantial proofs, and currently do not allow stratification of GERD patients for progression, outcome, and therapeutic effectiveness in clinical practice. The aim of this paper is to discuss the current knowledge regarding the GERD-BE-EAC sequence mainly focusing on the disputable and ambiguous status of proposed biomarkers to identify promising and reliable markers in order to provide more detailed insights into pathophysiological mechanisms and thus to improve prognostic and predictive therapeutic approaches.

High incidence of DNA ploidy abnormalities and increased Mcm2 expression may predict malignant change in oral proliferative verrucous leukoplakia

AIMS

To assess the DNA content of cases of oral proliferative verrucous leukoplakia (PVL) and correlate the DNA ploidy findings with the expression of Mcm2, geminin, and Ki67, and with clinicopathological data.

METHODS AND RESULTS

DNA quantification was performed by image cytometry using the ACIS III Automated Cellular Imaging System. Expression of Ki67, Mcm2 and geminin was determined by immunohistochemistry. There were 21 cases of PVL, the female/male ratio was 6:1, and the average age was 65.5 years. Seventeen patients (81.0%) did not report tobacco and alcohol consumption. Nine patients (42.9%) developed verrucous or squamous cell carcinoma. Levels of Mcm2 expression showed a positive correlation with increasingly severe epithelial changes (P = 0.03). Twenty patients had their DNA examined by ACIS III, and 19 (95%) showed aneuploidy. The frequency and severity of aneuploidy (P < 0.0001), the mean values of the DNA heterogeneity index (P < 0.0001) and the 5n-exceeding fractions (P = 0.0007) increased according to epithelial alterations. Abnormal DNA content was observed even in the more indolent lesions.

CONCLUSIONS

Mcm2 expression and DNA ploidy analysis could be used to predict areas of malignant transformation. The clinicopathological findings associated with the immunohistochemical and DNA ploidy results support the distinct and aggressive profile of this entity.

Occurrence of multipolar mitoses and association with Aurora-A/-B kinases and p53 mutations in aneuploid esophageal carcinoma cells

Background

Aurora kinases and loss of p53 function are implicated in the carcinogenesis of aneuploid esophageal cancers. Their association with occurrence of multipolar mitoses in the two main histotypes of aneuploid esophageal squamous cell carcinoma (ESCC) and Barrett's adenocarcinoma (BAC) remains unclear. Here, we investigated the occurrence of multipolar mitoses, Aurora-A/-B gene copy numbers and expression/activation as well as p53 alterations in aneuploid ESCC and BAC cancer cell lines.

Results

A control esophageal epithelial cell line (EPC-hTERT) had normal Aurora-A and -B gene copy numbers and expression, was p53 wild type and displayed bipolar mitoses. In contrast, both ESCC (OE21, Kyse-410) and BAC (OE33, OE19) cell lines were aneuploid and displayed elevated gene copy numbers of Aurora-A (chromosome 20 polysomy: OE21, OE33, OE19; gene amplification: Kyse-410) and Aurora-B (chromosome 17 polysomy: OE21, Kyse-410). Aurora-B gene copy numbers were not elevated in OE19 and OE33 cells despite chromosome 17 polysomy. Aurora-A expression and activity (Aurora-A/phosphoT288) was not directly linked to gene copy numbers and was highest in Kyse-410 and OE33 cells. Aurora-B expression and activity (Aurora-B/phosphoT232) was higher in OE21 and Kyse-410 than in OE33 and OE19 cells. The mitotic index was highest in OE21, followed by OE33 > OE19 > Kyse-410 and EPC-hTERT cells. Multipolar mitoses occurred with high frequency in OE33 (13.8 ± 4.2%), followed by OE21 (7.7 ± 5.0%) and Kyse-410 (6.3 ± 2.0%) cells. Single multipolar mitoses occurred in OE19 (1.0 ± 1.0%) cells. Distinct p53 mutations and p53 protein expression patterns were found in all esophageal cancer cell lines, but complete functional p53 inactivation occurred in OE21 and OE33 only.

Conclusions

High Aurora-A expression alone is not associated with overt multipolar mitoses in aneuploid ESCC and BAC cancer cells, as specifically shown here for OE21 and OE33 cells, respectively. Additional p53 loss of function mutations are necessary for this to occur, at least for invasive esophageal cancer cells. Further assessment of Aurora kinases and p53 interactions in cells or tissue specimens derived from non-invasive dysplasia (ESCC) or intestinal metaplasia (BAC) are necessary to disclose a potential causative role of Aurora kinases and p53 for development of aneuploid, invasive esophageal cancers.

Monitoring the reversible B to A-like transition of DNA in eukaryotic cells using Fourier transform infrared spectroscopy

The ability to detect DNA conformation in eukaryotic cells is of paramount importance in understanding how some cells retain functionality in response to environmental stress. It is anticipated that the B to A transition might play a role in resistance to DNA damage such as heat, desiccation and toxic damage. To this end, conformational detail about the molecular structure of DNA has been derived primarily from in vitro experiments on extracted or synthetic DNA. Here, we report that a B- to A-like DNA conformational change can occur in the nuclei of intact cells in response to dehydration. This transition is reversible upon rehydration in air-dried cells. By systematically monitoring the dehydration and rehydration of single and double-stranded DNA, RNA, extracted nuclei and three types of eukaryotic cells including chicken erythrocytes, mammalian lymphocytes and cancerous rodent fibroblasts using Fourier transform infrared (FTIR) spectroscopy, we unequivocally assign the important DNA conformation marker bands within these cells. We also demonstrate that by applying FTIR spectroscopy to hydrated samples, the DNA bands become sharper and more intense. This is anticipated to provide a methodology enabling differentiation of cancerous from non-cancerous cells based on the increased DNA content inherent to dysplastic and neoplastic tissue.

Biomarkers in Barrett’s esophagus and esophageal adenocarcinoma: Predictors of progression and prognosis

Barrett’s esophagus is a well-known premalignant lesion of the lower esophagus that is characterized by intestinal metaplasia of the squamous epithelium. It is clinically important due to the increased risk (0.5% per annum) of progression to esophageal adenocarcinoma (EA), which has a poor outcome unless diagnosed early. The current clinical management of Barrett’s esophagus is hampered by the lack of accurate predictors of progression. In addition, when patients develop EA, the current staging modalities are limited in stratifying patients into different prognostic groups in order to guide the optimal therapy for an individual patient. Biomarkers have the potential to improve radically the clinical management of patients with Barrett’s esophagus and EA but have not yet entered mainstream clinical practice. This is in contrast to other cancers like breast and prostate for which biomarkers are utilized routinely to inform clinical decisions. This review aims to highlight the most promising predictive and prognostic biomarkers in Barrett’s esophagus and EA and to discuss what is required to move the field forward towards clinical application.

Predictors of progression in Barrett's esophagus: current knowledge and future directions

Barrett's esophagus (BE) is the strongest risk factor for esophageal adenocarcinoma (EAC), a malignancy with persistently poor long-term outcomes. EAC is thought to develop through progression of metaplasia to dysplasia to invasive carcinoma. Identification of factors predicting progression to EAC would help in focusing surveillance, chemoprevention, or ablation for those deemed to be at highest risk of progression. We performed a comprehensive review of the literature and summarized current evidence on risk factors for progression in subjects with known BE. Clinical and demographic factors (age, male gender, length of BE segment) are associated with modestly increased odds of progression to EAC in some studies. Biomarkers such as aneuploidy and p53 loss of heterozygosity have been associated with increased risk of progression to high-grade dysplasia and/or EAC in single-center prospective cohort studies. Promising newer techniques and markers have been recently reported with the potential to help risk stratify BE subjects. Development of a comprehensive BE risk progression score comprised of both clinical and biomarker variables should be the ultimate goal and can be achieved by multicenter prospective collaborative efforts. Although it would be challenging, creation of such a score has the potential to improve outcomes and make the management of patients with BE more cost-effective.

Lgr5, an intestinal stem cell marker, is abnormally expressed in Barrett's esophagus and esophageal adenocarcinoma

Lgr5 (leucine-rich-repeat-containing G-protein-coupled receptor 5), a recently discovered intestinal stem cell marker, is expressed in premalignant lesions including Barrett's esophagus (BE) and cancers including colon cancer, ovarian cancer, and hepatocellular carcinoma. It was also recently found to be expressed in tumor spheres prepared from colon cancer, suggesting that it will likely serve as a cancer stem cell marker. We sought to examine Lgr5 as a biomarker in BE-associated neoplasia. Using standard immunohistochemistry, we performed immunostaining on 81 esophageal specimens (53 biopsy specimens and 28 surgical resections) representing BE, BE-associated dysplasia, and esophageal adenocarcinoma (EAC). Each immunostain was scored based on intensity of immunostaining and percentage of positive cells. For 24 EAC cases, survival analysis was performed with expression scores and other clinicopathological variables. We found that Lgr5 expression was detected in 70% of BE cases and between 90 and 100% of advanced dysplastic lesions and EAC. The intensity of expression was significantly higher in high-grade dysplasia and EAC than BE. In EAC, high Lgr5 expression scores (> or = 5) were associated with worse survival, independent of stage, age, and neoadjuvant/adjuvant therapy (P = 0.03). Our findings suggest that Lgr5 has potential utility as a biomarker for BE-associated dysplasia and EAC.

Benefit of baseline cytometry for surveillance of patients with Barrett's esophagus

BACKGROUND

The current gold standard for the surveillance of Barrett's esophagus is the Seattle four-quadrant biopsies protocol (4-QB). Using endoscopic brush cytology, this study prospectively investigated whether digital image cytometry (DICM) is of additional benefit over regular histology as a predictor for progression to high-grade dysplasia or cancer during a surveillance of at least 3 years.

METHODS

The prospective cohort in this study included 93 patients (72% male) with Barrett's esophagus, baseline endoscopies, and at least one DICM in addition to 4-QB who had been followed up a minimum of 3 years at the time of analysis. High-grade dysplasia (HGD) and adenocarcinoma were defined as primary end points. The DICM was performed on Feulgen-restained cytology smears with a continuous collision detection (CCD) three-chip color video camera (Sony) and an AutoCyte QUIC DNA workstation.

RESULTS

Of the 93 patients, 11 presented with the diagnosis of HGD and adenocarcinoma at baseline endoscopy. The remaining 82 patients were analyzed after a median follow-up time of 44 months (range, 36-65 months). Of these 82 patients, 9 (11%) had low-grade dysplasia (LGD) at baseline histology: One of two patients with LGD and aneuploid DICM showed HGD at follow-up assessment, whereas none of seven patients with LGD and diploid DICM had development of HGD. Of the 82 patients, 73 (89%) had either specialized intestinal metaplasia (SIM) without dyplasia or indefinite findings for dysplasia at baseline histology. Of the eight patients with SIM and intermediate/aneuploid DICM, two had development of HGD. None of those with negative or indefinite findings for dysplasia and diploid DICM had HGD at the follow-up evaluation. In summary, the three patients who had development of HGD showed a pathologic DICM at baseline, and no patient with diploid DICM had HGD.

CONCLUSIONS

Cytometry from brush cytology as an add-on to histology appears to be of additional benefit during surveillance of Barrett's esophagus. Whereas an aneuploid/intermediate DICM warrants an early re-endoscopy, a diploid DICM underscores the low-risk status especially of patients with low-grade dysplasia.

Aneuploidy and overexpression of Ki67 and p53 as markers for neoplastic progression in Barrett's esophagus: a case-control study

OBJECTIVES

Surveillance of patients with Barrett's esophagus (BE) aims at early detection and treatment of neoplastic changes, particularly esophageal adenocarcinoma (EAC). The histological evaluation of biopsy samples has its limitations, and biomarkers may improve early identification of BE patients at risk for progression to EAC. The aim of this study was to determine the predictive value of p53, Ki67, and aneuploidy as markers of neoplastic progression in BE.

METHODS

A total of 27 BE patients with histologically proven progression to high-grade dysplasia (HGD) or EAC (cases) and 27 BE patients without progression (controls) were selected and matched for age, gender, and duration of follow-up. Dysplasia grade was determined in 212 biopsy samples obtained during surveillance endoscopies from cases and in 231 biopsy samples collected from controls. DNA ploidy status was determined by flow cytometry, whereas Ki67 and p53 expression was determined by immunohistochemistry. Hazard ratios (HRs) were calculated by Cox regression adjusted for potentially confounding variables.

RESULTS

A univariate analysis showed that low-grade dysplasia (LGD) increased the risk of developing HGD/EAC compared with no dysplasia (HR 3.6; 95% confidence interval (CI): 1.6 - 8.1). Aneuploidy (HR 3.5; 95% CI: 1.3-9.4), strong Ki67 overexpression (HR 5.2; 95% CI: 1.5-17.6), and moderate p53 overexpression (HR 6.5; 95% CI: 2.5-17.1) were also associated with an increased risk of developing HGD/EAC, independent of the histological result. A multivariable analysis showed that in the presence of LGD, p53 overexpression, and to a lesser extent, Ki67 overexpression remained important risk factors for neoplastic progression, whereas aneuploidy was no longer predictive.

CONCLUSIONS

p53 overexpression and, to a lesser extent, Ki67 overexpression could predict neoplastic progression in BE irrespective of the histological result. These markers may be useful for identifying patients at an increased risk of developing EAC, either alone or used as a panel.

Metaplastic esophageal columnar epithelium without goblet cells shows DNA content abnormalities similar to goblet cell-containing epithelium

OBJECTIVES

The mucosa of patients with columnar-lined esophagus recognized on endoscopy usually shows epithelium with and without goblet cells. Columnar epithelium with goblet cells ("Barrett's esophagus") is generally believed to represent a premalignant lesion and has been shown to contain DNA abnormalities. However, the biological properties of non-goblet columnar epithelium remain unknown. The purpose of this study was to determine the DNA content properties of non-goblet epithelium in patients with metaplastic columnar epithelium of the esophagus.

METHODS

Mucosal biopsies of the esophagus from 68 patients with columnar metaplasia of the esophagus (22 without goblet cells and 46 with goblet cells) and 19 patients with normal gastric mucosa (controls) were histologically evaluated for the density of goblet cells. The latter group was divided into low-density, high-density, and very high-density goblet cell subgroups. Tissue sections of non-goblet epithelium and goblet cell epithelium (where present) were evaluated by image cytometry, and high-fidelity DNA histograms were created to indicate the G0/G1 peak DNA index (DI), DNA content heterogeneity index (HI), and the percentage of cells with DNA exceeding 5N (5N-EC). G0/G1 peaks with DI>1.1 were considered aneuploid.

RESULTS

Normal gastric controls showed a mean peak DI of 1.02+/-0.03 and an HI of 11.6+/-0.7. None of the controls revealed aneuploidy or 5N-EC. Patients with metaplastic columnar epithelium with goblet cells showed a DI of 1.15+/-0.12, HI of 18.2+/-2.1, mild aneuploidy in 54% of the cases, and 5N-EC in 15% of the cases, all of which were significantly higher than in controls. Patients with metaplastic columnar epithelium without goblet cells showed DNA content results statistically similar to those of patients with metaplastic columnar epithelium with goblet cells, and also revealed significantly higher values compared with those of controls. Furthermore, there were no significant differences in any of the key DNA content abnormalities between non-goblet and goblet cell-containing epithelium in patients with metaplastic columnar epithelium with goblet cells, or between these two types of epithelium according to the density of goblet cells.

CONCLUSIONS

DNA content abnormalities occur with equal frequency and extent in metaplastic columnar epithelium of the esophagus without goblet cells compared with metaplastic columnar epithelium with goblet cells. These findings suggest that metaplastic non-goblet columnar epithelium of the esophagus may have neoplastic potential.

DNA ploidy abnormalities in basal and superficial regions of the crypts in Barrett's esophagus and associated neoplastic lesions

The purpose of this study was to define the zonal DNA content distribution in the basal versus the superficial crypt cells in Barrett's esophagus (BE) and related neoplastic lesions. One hundred and five tissue sections of BE patients and 12 gastric tissue section as controls were stained with hematoxylin-eosin and Feulgen and high-fidelity DNA histograms were generated from whole crypts (n=117) and also separately from the basal and superficial portions of the crypts (n=71). Three parameters were analyzed: (1) peak DNA index (DI), classified into diploidy (DI=0.9-1.1) or aneuploidy (DI>1.1), the latter of which was further divided into 3 types: mild (DI=1.1-1.3), moderate (DI=1.3-1.8), and severe (DI>1.8). (2) Heterogeneity index (HI), representing groups of cells with different DNA content. (3) Percentage of cells with DI exceeding 5N rate (5N-ER). In full crypts, compared with gastric controls, the prevalence of DNA aneuploidy increased significantly (P<0.01) from nondysplastic BE to basal crypt dysplasia (BCD), low-grade dysplasia (LGD), high-grade dysplasia (HGD), and adenocarcinoma (AC). Nondysplastic BE, BCD, and LGD had mostly mild aneuploidy, and the majority of HGD and AC had either moderate or severe aneuploidy. In addition, both HI and 5N-ER increased progressively from BCD and LGD to HGD and AC (P<0.01). When analyzed separately, the superficial crypt cells were diploid in nondysplastic BE and BCD, but were aneuploid in 50% of LGD and 100% of HGD cases. In contrast, basal crypt cells were aneuploid in 37% of nondysplastic BE, 50% of BCD, 73% of LGD, and 100% of HGD cases. A similar progressive increase in the HI and 5N-ER values in basal crypt cells was observed with dysplastic progression. The changes in DNA ploidy profiles of basal crypt cells in BCD and LGD were remarkably similar. These results suggest that with neoplastic progression, dysplastic changes in BE begin in the basal crypt cells and then extend further up the crypts, and BCD represents a true early form of dysplasia limited to the crypt bases.

DNA ploidy analysis by image cytometry helps to identify oral epithelial dysplasias with a high risk of malignant progression

Abnormal DNA content (aneuploidy) has been associated with malignant and premalignant epithelial lesions. The presence of aneuploidy in tumours at an early stage and in dysplastic lesions suggests that analysis of DNA content may be a useful marker for determination of prognosis in these lesions. The aim of this study was to use DNA image cytometry to evaluate aneuploidy in oral dysplastic lesions and to determine whether aneuploidy is associated with malignant progression. Forty-two lesions of oral epithelial dysplasias (OED) that had progressed to oral squamous cell carcinoma (OSCC) and 44 lesions that did not progress were analysed for DNA ploidy using image cytometry of nuclear monolayers prepared from paraffin-embedded tissue. Forty-two OSCC that had arisen from the OED cases and five samples of normal oral mucosa samples (NOM) were also examined. Aneuploidy was found in 14/42 (33.3%) of the OED that progressed, but in only 5/44 (11.3%) of OED that did not progress (p=0.01). A total of 19 OED were aneuploid of which 74% showed malignant progression compared to only 42% of the diploid lesions. The sensitivity and specificity of DNA image cytometry to detect cases with high risk of malignant progression was 0.33 and 0.88, respectively. The PPV and NPV were 0.74 and 0.58. We conclude that aneuploid oral dysplastic lesions have a high risk of malignant progression and that DNA image cytometry might help to identify those lesions most at risk.

Assessment of chromosomal gains as compared to DNA content changes is more useful to detect dysplasia in Barrett's esophagus brush cytology specimens

Abnormal DNA ploidy status has been suggested as a prognostic factor for Barrett's esophagus progression into esophageal adenocarcinoma (EAC). The aim of the study was to compare image cytometry DNA analysis (ICDA) and fluorescent in situ hybridization (FISH) in the assessment of DNA ploidy status in Barrett's esophagus (BE), and to determine the value of these abnormalities as an adjunct to conventional cytology in detection of dysplasia and EAC. Brush cytology specimens of 90 BE patients were examined using ICDA and FISH with peri-centromeric probes for chromosomes 7 and 17. The results of ICDA and FISH were compared with each other, and with dysplasia grade or EAC as determined by histology and cytology. FISH and ICDA detected abnormalities in 41% (37/90) and 22% (19/90) of the BE cases, respectively. Gains of chromosome 7 and/or 17 were present in 13% of nondysplasia cases, which further increased with dysplasia stage, while overall DNA content aneuploidy was detected predominantly in high grade dysplasia (HGD) and EAC. Using FISH results combined with cytology, we were able to identify IND/LGD (indefinite/ low grade dysplasia) with a sensitivity and specificity of 75 and 76%, respectively. FISH alone detected HGD/EAC with a high sensitivity and specificity of 85 and 84%, which was superior to that of cytology alone. Thus, FISH is more sensitive than ICDA to detect chromosomal abnormalities in BE brush cytology specimens. FISH detects chromosomal gains in early stages of BE and represents a valuable adjunct to conventional cytology to detect dysplasia or EAC.

A comparison of conventional cytology, DNA ploidy analysis, and fluorescence in situ hybridization for the detection of dysplasia and adenocarcinoma in patients with Barrett's esophagus

New detection methods with prognostic power are needed for early identification of dysplasia and esophageal adenocarcinoma (EA) in patients with Barrett's esophagus (BE). This study assessed the relative sensitivity and specificity of conventional cytology, DNA ploidy analysis with digital image analysis (DIA), and fluorescence in situ hybridization (FISH) for the detection of dysplasia and adenocarcinoma in endoscopic brushing specimens from 92 patients undergoing endoscopic surveillance for BE. FISH used probes to 8q24 (C-MYC), 9p21 (P16), 17q12 (HER2), and 20q13. Four-quadrant biopsies taken every centimeter throughout visible Barrett's mucosa were used as the gold standard. The sensitivity of cytology, DIA, and FISH for low-grade dysplasia was 5%, 5%, and 50%, respectively; for high-grade dysplasia (HGD), 32%, 45%, and 82%, respectively; and for EA, 45%, 45%, and 100%, respectively. FISH was more sensitive (P < .05) than cytology and DIA for low-grade dysplasia, HGD, and EA. The specificity of cytology, DIA, and FISH among patients (n = 14) with tissue showing only benign squamous mucosa was 93%, 86%, and 100% (P = .22), respectively. All patients with a polysomic FISH result had HGD and/or EA within 6 months (n = 33). There was a significant difference between FISH categories (negative, 9p21 loss, gain of a single locus, and polysomy) for progression to HGD/EA (P < .001). These findings suggest that FISH has high sensitivity for the detection of dysplasia and EA in BE patients, with the power to stratify patients by FISH abnormality for progression to HGD/EA. Additional studies are needed to further evaluate the clinical use of FISH.

Microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence

AIM: To investigate the microsatellite alterations in phenotypically normal esophageal squamous epithelium and metaplasia-dysplasia-adenocarcinoma sequence.

METHODS: Forty-one specimens were obtained from esophageal cancer (EC) patients. Histopathological assessment identified 23 squamous cell carcinomas (SCC) and 18 adenocarcinomas (ADC), including only 8 ADC with Barrett esophageal columnar epithelium (metaplasia) and dysplasia adjacent to ADC. Paraffin-embedded normal squamous epithelium, Barrett esophageal columnar epithelium (metaplasia), dysplasia and esophageal tumor tissues were dissected from the surrounding tissues under microscopic guidance. DNA was extracted using proteinase K digestion buffer, and DNA was diluted at 1:100, 1:1000, 1:5000, 1:10 000 and 1:50 000, respectively. Seven microsatellite markers (D2S123, D3S1616, D3S1300, D5S346, D17S787, D18S58 and BATRII loci) were used in this study. Un-dilution and dilution polymerase chain reactions (PCR) were performed, and microsatellite analysis was carried out.

RESULTS: No statistically significant difference was found in microsatellite instability (MSI) and loss of heterozygosity (LOH) of un-diluted DNA between SCC and ADC. The levels of MSI and LOH were high in the metaplasia-dysplasia-adenocarcinoma sequence of diluted DNA. The more the diluted DNA was, the higher the rates of MSI and LOH were at the above 7 loci, especially at D3S1616, D5S346, D2S123, D3S1300 and D18S58 loci.

CONCLUSION: The sequence of metaplasia-dysplasia-adenocarcinoma is associated with microsatellite alterations, including MSI and LOH. The MSI and LOH may be the early genetic events during esophageal carcinogenesis, and genetic alterations at the D3S1616, D5S346 and D3S123 loci may play a role in the progress of microsatellite alterations.

Gains and amplifications of c-myc, EGFR, and 20.q13 loci in the no dysplasia-dysplasia-adenocarcinoma sequence of Barrett's esophagus

The progression of Barrett's esophagus to esophageal adenocarcinoma is often characterized by the accumulation of genetic abnormalities. The goal was to evaluate the copy number alterations of several oncogene loci, including 7p12 [epidermal growth factor receptor (EGFR)], 8q24 (c-myc), and 20q13 in the sequence of no dysplasia-dysplasia-adenocarcinoma of Barrett's esophagus. Fluorescence in situ hybridization with DNA probes for the centromeric region of chromosome 7 and the locus-specific regions of 7p12 (EGFR), 8q24 (c-myc), and 20q13 was applied on 99 brush cytology specimens of patients with Barrett's esophagus with different stages of dysplasia or esophageal adenocarcinoma. Gains (3-4 copies) of chromosome 17, 8q24 (c-myc), and 20q.13 loci were found in the low frequencies in nondysplastic Barrett's esophagus. Their frequencies increased with the stage of dysplasia and reached a high incidence in esophageal adenocarcinoma. Amplification (>4 copies) of at least 1 of the loci was observed in 14% of high-grade dysplasia and increased to 50% in esophageal adenocarcinoma (P = 0.015). The most frequently amplified locus was c-myc (18%), followed by 20q13 (13%) and EGFR (11%) in the high-grade dysplasia/esophageal adenocarcinoma cases. High amplification levels (>10 copies) of the loci were more frequent in esophageal adenocarcinoma (72%) compared with high-grade dysplasia (20%; P = 0.049). Amplifications of the c-myc, EGFR, and 20q12 loci may serve as diagnostic markers to identify patients with Barrett's esophagus with high-grade dysplasia or esophageal adenocarcinoma. Gains of the loci might be of value as prognostic markers because they are already present in nondysplasia cases and may precede the later event of the amplification as observed in high-grade dysplasia and esophageal adenocarcinoma.

Comparison of DNA histograms by standard flow cytometry and image cytometry on sections in Barrett's adenocarcinoma

Background

The purpose of this study was to compare DNA histograms obtained by standard flow cytometry (FC) and high fidelity image cytometry on sections (ICS) in normal gastrointestinal mucosa and Barrett's adenocarcinoma (BAC).

Conclusion

ICS detects DNA aneuploidy in all BAC samples while FC missed the diagnosis of aneuploidy in 29%. In addition, ICS provides more information on HI and G2 exceeding rates.

Neoplastic precursor lesions in Barrett's esophagus

Barrett's esophagus, currently defined as endoscopically apparent columnar metaplasia of the esophagus with histologic documentation of goblet cells, is the precursor to esophageal adenocarcinoma. However, not all patients with this disorder require intensive surveillance. Pathologic diagnosis and grading of dysplasia in mucosal biopsies remains the best and most widely used method of determining which patients are at highest risk for neoplastic progression. The task of diagnosing dysplasia suffers from considerable interobserver variability. Therefore, consultation with expert gastrointestinal pathologists to confirm the diagnosis of dysplasia before definitive management is highly advisable. Adjunctive methods to improve reproducibility, such as immunostaining for alpha-methylacyl-CoA racemase, show promise but require confirmation in larger studies. This article focuses on dysplasia in Barrett's esophagus in terms of its classification, pathologic diagnostic criteria, limitations, natural history, and treatment.

Detection of endogenous biomolecules in Barrett's esophagus by Fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy provides a unique molecular fingerprint of tissue from endogenous sources of light absorption; however, specific molecular components of the overall FTIR signature of precancer have not been characterized. In attenuated total reflectance mode, infrared light penetrates only a few microns of the tissue surface, and the influence of water on the spectra can be minimized, allowing for the analyses of the molecular composition of tissues. Here, spectra were collected from 98 excised specimens of the distal esophagus, including 38 squamous, 38 intestinal metaplasia (Barrett's), and 22 gastric, obtained endoscopically from 32 patients. We show that DNA, protein, glycogen, and glycoprotein comprise the principal sources of infrared absorption in the 950- to 1,800-cm(-1) regime. The concentrations of these biomolecules can be quantified by using a partial least-squares fit and used to classify disease states with high sensitivity, specificity, and accuracy. Moreover, use of FTIR to detect premalignant (dysplastic) mucosa results in a sensitivity, specificity, positive predictive value, and total accuracy of 92%, 80%, 92%, and 89%, respectively, and leads to a better interobserver agreement between two gastrointestinal pathologists for dysplasia (kappa = 0.72) versus histology alone (kappa = 0.52). Here, we demonstrate that the concentration of specific biomolecules can be determined from the FTIR spectra collected in attenuated total reflectance mode and can be used for predicting the underlying histopathology, which will contribute to the early detection and rapid staging of many diseases.

Efficient automated assessment of genetic abnormalities detected by fluorescence in situ hybridization on brush cytology in a Barrett esophagus surveillance population

BACKGROUND

Automated assessment of genetic abnormalities detected by fluorescence in situ hybridization (FISH) in brush cytology specimens from patients with Barrett esophagus (BE) may enhance the clinical applicability of this methodology. The objectives of this study were to validate a novel, automated, proprietary system (CytoVison SPOT AX) for the assessment of FISH abnormalities in BE brush cytology and, subsequently, to use this automated method for screening of a BE surveillance cohort.

METHODS

FISH with DNA probes for chromosomes 9, 17, and Y, and for the 9p21 (p16), 17q11.2 (Her2/neu), and 17p13.1 (p53) loci was applied on brush cytology specimens from a surveillance cohort of 151 patients with BE. Validation of the automated system was performed by comparison of the automated FISH results with manual scores for the first 60 patients.

RESULTS

There was 98% concordance between manual and automated FISH analysis with kappa values from 0.49 to 1 for the different probes. The loss of 17p13.1 (p53) was observed in only 5% of patients with no dysplasia (ND) and in 9% of patients with low-grade dysplasia (LGD) but increased to 46% in patients with high-grade dysplasia (HGD) (P < .005; Fisher exact test). Chromosomes 9 and 17 were observed in 6% of patients with ND, in 21% of patients with LGD, and in 62% of patients with HGD (P < .05). Ten percent of patients with ND had loss of the Y chromosome, which increased to 27% in patients with HGD (P< .05). The amplification of 17q11.2 (Her2/neu) was detected in 62% of patients with HGD (P < .001).

CONCLUSIONS

The current investigation indicated that the CytoVison SPOT AX is an objective, efficient system for the analysis of DNA-FISH on BE brush cytology and is applicable for analyzing large populations of BE patients. In the current study cohort, the loss of 17p13.1 (p53), Y chromosome loss, and polysomy of chromosomes 17 and 9 were correlated with increasing grade of dysplasia in patients with BE.

High-fidelity DNA histograms in neoplastic progression in Barrett's esophagus

This study describes the high-fidelity DNA histograms in different stages of neoplastic progression to Barrett's adenocarcinoma (BAC). High-fidelity DNA histograms were obtained with image cytometry on sections, and were classified based on DNA index values of the peaks into diploid, mild aneuploid, moderate aneuploid and severe aneuploid. Heterogeneity index (HI) representing cells with different DNA content and the 5N exceeding cell fraction were determined. One hundred and eighty-seven cases, including 34 normal gastrointestinal mucosa (control), 66 Barrett's-specialized intestinal metaplasia (SIM), 22 low-grade dysplasia (LGD), 22 high-grade dysplasia (HGD) and 43 BAC were investigated. Controls showed sharp diploid peaks with HI values less than 13, and no 5N exceeding nuclei. SIM showed a spectrum of histograms including diploid, mild aneuploid and moderate aneuploid histograms. The frequency and severity of aneuploidy increased with worsening histological grades of dysplasia. All BAC cases were aneuploid, with moderate or severe aneuploidy. Marked elevated HI values (>20) and 5N exceeding fractions (>5%) were found in 5%, 32%, 50% and 88% of cases with SIM, LGD, HGD and BAC, respectively. The high-fidelity DNA histograms suggest that (1) Barrett's SIM may already be dysplastic in nature, and all BAC may be markedly aneuploid; and (2) elevated cellular DNA heterogeneity and 5N fractions may be markers of progressive chromosomal changes and 'unstable aneuploidy' that identifies progressive lesions.

Endoprevention of esophageal cancer: endoscopic ablation of Barrett's metaplasia and dysplasia

This review describes the use of endoscopic therapy for the treatment of Barrett's disease and the prevention of esophageal carcinoma, predominantly a disease of older white men. While the term endoprevention may be novel, gastroenterologists have been using endoscopic techniques to prevent colon cancer for decades. For the endoprevention of Barrett's carcinoma, the regulatory approval for the use of porfimer sodium photodynamic therapy was an important milestone, as this treatment has been proven to safely ablate Barrett's glandular epithelium, including high-grade dysplasia, and significantly decrease the risk for the development of invasive cancer in several single-center studies, a prospective multicenter randomized controlled study using expert centralized histopathology analysis and long-term single-center results. Newer methods of mucosal ablation, such as the radiofrequency balloon, have been developed for the treatment of patients with Barrett's metaplasia or dysplasia. These newly developed techniques are able to treat large fields of glandular epithelium in a short treatment procedure using safe, effective, durable methods for the complete ablation of Barrett's metaplasia and low-grade dysplasia. These techniques may finally allow the interventional gastrointestinal endoscopist to prevent the development of esophageal carcinoma, just as colonoscopy with polypectomy has prevented colon cancer. However, it will be critically important to document the safety, durability and efficacy of these devices. Ultimately, the impact of successful Barrett's ablation on the incidence of Barrett's carcinoma, and the need for postablation surveillance endoscopy must be determined.

Deoxyribonucleic acid content as an indicator of progression of squamous cell carcinogenesis in the esophagus: Comparative analysis on imprint-cytospin and tissue section preparation

BACKGROUND

The purpose of this study was to explore the potential use of image analysis on tissue sections preparation as a predictive marker of early malignant changes during squamous cell (SC) carcinogenesis in the esophagus. Results of DNA ploidy quantification on formalin-fixed, paraffin-embedded tissue using two different techniques were compared: imprint-cytospin and 6 microm thick tissue sections preparation.

METHODS

This retrospective study included 26 surgical specimens of squamous cell carcinoma (SCC) from patients who underwent surgery alone at the Department of Surgery in CHUV Hospital in Lausanne between January 1993 and December 2000. We analyzed 53 samples of healthy tissue, 43 tumors and 7 lymph node metastases.

RESULTS

Diploid DNA histogram patterns were observed in all histologically healthy tissues, either distant or proximal to the lesion. Aneuploidy was observed in 34 (79%) of 43 carcinomas, namely 24 (75%) of 32 early squamous cell carcinomas and 10 (91%) of 11 advanced carcinomas. DNA content was similar in the different tumor stages, whether patients presented with single or multiple synchronous tumors. All lymph node metastases had similar DNA content as their primary tumor.

CONCLUSIONS

Early malignant changes in the esophagus are associated with alteration in DNA content, and aneuploidy tends to correlate with progression of invasive SCC. A very good correlation between imprint-cytospin and tissue section analysis was observed. Although each method used here showed advantages and disadvantages; tissue sections preparation provided useful information on aberrant cell-cycle regulation and helped select the optimal treatment for the individual patient along with consideration of other clinical parameters.

Photodynamic therapy for Barrett's esophagus with high-grade dysplasia

This article describes advances in photodynamic therapy for patients with Barrett's esophagus and high-grade dysplasia-an important, minimally invasive treatment option proven to safely and durably ablate Barrett's dysplasia and prevent carcinoma while preserving the gastroesophageal junction.

DNA index determination with Automated Cellular Imaging System (ACIS) in Barrett's esophagus: comparison with CAS 200

Background

For solid tumors, image cytometry has been shown to be more sensitive for diagnosing DNA content abnormalities (aneuploidy) than flow cytometry. Image cytometry has often been performed using the semi-automated CAS 200 system. Recently, an Automated Cellular Imaging System (ACIS) was introduced to determine DNA content (DNA index), but it has not been validated.

Methods

Using the CAS 200 system and ACIS, we compared the DNA index (DI) obtained from the same archived formalin-fixed and paraffin embedded tissue samples from Barrett's esophagus related lesions, including samples with specialized intestinal metaplasia without dysplasia, low-grade dysplasia, high-grade dysplasia and adenocarcinoma.

Results

Although there was a very good correlation between the DI values determined by ACIS and CAS 200, the former was 25% more sensitive in detecting aneuploidy. ACIS yielded a mean DI value 18% higher than that obtained by CAS 200 (p < 0.001; paired t test). In addition, the average time required to perform a DNA ploidy analysis was shorter with the ACIS (30–40 min) than with the CAS 200 (40–70 min). Results obtained by ACIS gave excellent inter-and intra-observer variability (coefficient of correlation >0.9 for both, p < 0.0001).

Conclusion

Compared with the CAS 200, the ACIS is a more sensitive and less time consuming technique for determining DNA ploidy. Results obtained by ACIS are also highly reproducible.

Surveillance and screening for Barrett esophagus and adenocarcinoma

Current recommendations for screening and surveillance of Barrett esophagus and related lesions are based on recent guidelines by the Practice Parameters Committee of the American College of Gastroenterology. The purpose of this review is to critically examine the rationale and evidence behind these recommendations. There is strong rationale for vigorous initial testing to document the baseline status and identify early adenocarcinoma, and for surveillance of high-grade dysplasia. Recommendations for esophagectomy in patients with high-grade dysplasia need to be individualized. However, recommendations for surveillance of low-grade dysplasia and specialized intestinal metaplasia without dysplasia are largely opinion statements not well supported by objective data. Although cancers identified by surveillance are at earlier stages than those diagnosed without prior endoscopic evaluation, surveillance failures are common. Recommendations for screening and surveillance are not evidence-based and unlikely to alter national mortality from esophageal adenocarcinoma. Their impact on individual patients depends on individual circumstances. Current recommendations are limited by inconsistent endoscopic findings and sampling errors, inconsistent histologic diagnoses of Barrett esophagus and dysplasia, and our poor understanding of the natural history of various histologic lesions. Future directions include validation of methods that reduce these inconsistencies by in vivo detection of abnormalities and by objective diagnostic markers besides grades of dysplasia, such DNA content analysis and molecular markers, and improved understanding of the disease progression. Effective screening programs depend on development of simple, inexpensive, and reliable methods to identify the small group of patients truly at high risk for adenocarcinoma for endoscopic screening.

The molecular biology of esophageal adenocarcinoma

BACKGROUND

Barrett's esophagus is an acquired metaplastic change that occurs in the distal esophagus secondary to chronic gastroesophageal reflux. This premalignant condition forms the most important risk factor for developing esophageal adenocarcinoma, which is an extremely aggressive tumor with a 5-year survival rate of less than 25%. Carcinomas that arise in the setting of Barrett's esophagus are thought to develop as part of the metaplasia-dysplasia-carcinoma sequence.

OBJECTIVE

To review the current knowledge on the genomic alterations involved in the development of Barrett's esophagus and its progression to dysplasia and/or cancer.

RESULTS

Several changes in gene structure, gene expression, and protein structure are associated with the progression of Barrett's esophagus to adenocarcinoma. Accumulation of these changes seems to be essential, rather than the exact sequence of these changes. Multiple molecular pathways are involved and interact with each other. Alterations in tumor suppressor genes, amongst which p53 and p16, are early events in the metaplasia-dysplasia-adenocarcinoma sequence, followed by loss of cell cycle checkpoints. Ongoing genomic instability leads to cumulative genetic errors and thereby the generation of multiple clones of transformed cells.

CONCLUSIONS

Within the multistep process of esophageal adenocarcinogenesis, to date no single molecular marker came forward able to predict who will and who will not develop cancer in the setting of Barrett's esophagus. Instead, panels of markers need to be developed in the future allowing to indicate disease progression. Identification of crucial molecular pathways involved in esophageal adenocarcinogenesis would ultimately improve therapy and facilitate development of new treatment strategies.