Dysplasia Detection Rate Research Articles

Limited applicability of chromoendoscopy-guided confocal laser endomicroscopy as daily-practice surveillance strategy in Crohn’s disease

Patients with longstanding ulcerative colitis have an increased risk for developing colorectal cancer (CRC). Although the risk for ulcerative colitis is well-established, for Crohn's disease data are contradictory. This study aimed to determine the number of patients with Crohn's disease with dysplasia who are undergoing surveillance and to assess the diagnostic accuracy of chromoendoscopy (CE) combined with integrated confocal laser endomicroscopy (iCLE) for differentiating dysplastic versus nondysplastic lesions. Patients with longstanding Crohn's colitis undergoing surveillance colonoscopy were included in this multicenter, prospective, cohort study. Surveillance was performed with CE, and lesions were assessed with iCLE for differentiation. All lesions were removed and sent for pathology as the reference standard. Between 2010 and 2014, a total of 61 patients with Crohn's colitis were included in 5 centers. Seventy-two lesions, of which 7 were dysplastic, were detected in 6 patients (dysplasia detection rate 9.8%); none included high-grade dysplasia or cancer. Combined CE with iCLE for differentiating neoplastic from nonneoplastic lesions had accuracy of 86.7% (95% confidence interval [CI], 78.1-95.3), sensitivity of 42.9% (95% CI, 11.8-79.8), and specificity of 92.4% (95% CI, 80.9-97.6). For CE alone, this was 80.3% (95% CI, 70.7-89.9), 28.6% (95% CI, 5.1-69.7), and 86.4% (95% CI, 80.9-97.6). The study terminated early because of frequent failure of the endoscopic equipment. This study shows a low incidence of dysplastic lesions found during surveillance colonoscopy in patients with longstanding extensive Crohn's colitis. The accuracy of both CE alone and CE in combination with iCLE was relatively good, although the sensitivity for both was poor. Because of frequent equipment failure, iCLE has limited applicability in daily practice as a surveillance strategy.

PTU-009 The utility of routine chromoendoscopy for detection of dysplastic lesions during surveillance colonoscopy in patients with colonic inflammatory bowel disease. does research translate to clinical practice?

Introduction Dysplasia in colonic inflammatory bowel disease (IBD) is often multifocal and flat. Chromoendoscopy (CE) has been shown in prospective studies to improve dysplasia detection rates by improving the ability to detect subtle mucosal changes. 1 The utility of CE in dysplasia detection in patients with IBD during routine clinical practice has not been reported so far. We aimed to compare the yield of dysplastic lesions detected by CE with standard white light endoscopy (WLE). Method Retrospective cohort study of patients with long standing (>7 years) colonic IBD undergoing surveillance colonoscopy at Leeds Teaching Hospital NHS Trust between January 2012 to December 2013. Details of diagnosis, duration of disease and outcomes of the colonoscopy were collected from the endoscopy database, electronic patient records and patient notes. Results There were 120 colonoscopies in the CE group and 220 colonoscopies in the WLE group. The groups were well matched for all demographic variables. 27 dysplastic lesions were detected in 20 patients in the CE group and 9 dysplastic lesions were detected in 6 patients in the WLE group. All the lesions were detected on targeted biopsy and harboured low grade dysplasia. The adjusted prevalence ratio (on a per patient basis) for detecting any dysplastic lesion was 4.6 (95% CI 1.6–13.7) in favour of CE. Conclusion CE colonoscopy improves detection of dysplastic lesions during surveillance colonoscopy of patients with colonic IBD even in routine clinical practice, confirming data from prospective trials. CE should be the standard of care for all IBD surveillance procedures as advocated by both BSG and ECCO guidelines. Disclosure of interest None Declared. Reference Subramanian V, Mannath J, Ragunath K, et al . Meta-analysis: the diagnostic yield of chromoendoscopy for detecting dysplasia in patients with colonic inflammatory bowel disease. Aliment Pharmacol Ther. 2011;33(3):304–12

PTH-028 Real world surveillance of barrett’s oesophagus – does it make a difference using the prague classification or following seattle biopsy protocol?: Abstract PTH-028 Table 1

Introduction BSG Barrett’s Surveillance guidance recommends that the Prague Classification (PC) should be used to describe a Barrett’s segment and Seattle Protocol (SP) be used when taking biopsies. Previous studies have reported poor compliance with such protocols. We sought to investigate the extent to which adherence to advice affected outcomes in our patient cohort. We aimed to investigate the impact of 1) reported use of the Prague classification and 2) adherence to the Seattle protocol, on the detection of all dysplasia and advanced dysplasia (HGD, or in-situ adenocarcinoma). Method HICCS Endoscopic Reporting System was searched for all detected Barrett’s oesophagus between Oct 2010–Oct 2014 (n = 587 procedures). Only specific surveillance cases were included (index and specific recall cases excluded). Endoscopy reports were checked and histology results retrieved from the Welsh Clinical Portal system. Differences in dysplasia detection rates for 1) PC used versus PC not used, and 2) SP followed versus SP not followed were tested using the Chi-squared test. Numbers of biopsies in each SP group were compared using two-tailed t-test. Significance level set at p Results In the 4 year study period, 367 Barrett’s surveillance procedures were performed in 220 patients. PC was reported in 106 (28.9%) and SP followed in 116 (31.6%) of procedures. The dysplasia rates are shown in the Table. There was a significant increase in detection rate of all types of dysplasia and advanced dysplasia (AD) when PC was used and where SP was followed. Significantly more biopsies were taken in the SP followed group, both for short (p = 0.037) and longer (>3 cm) segments (p Conclusion Adherence to recommended reporting and biopsy protocols may just reflect deeper interest in Barrett’s surveillance or greater experience level. Even if only surrogate markers for ‘quality’ of examination, their use marked clinically relevant differences in dysplasia detection, which in turn is linked to numbers of patients who may require endotherapy or radiofrequency ablation. Disclosure of interest None Declared.

PTU-327 An evaluation of the effect of using an acetic acid protocol for the detection of dysplasia in barrett’s oesophagus in a district general hospital setting: Abstract PTU-327 Table 1

Introduction Studies have suggested that mucosal enhancement techniques, such as acetic acid (AA) spray may increase detection of advanced dysplasia during surveillance of Barrett’s oesophagus. A standardised AA protocol was adopted by 3 consultants and a nurse endoscopist (NE) from 2011, other endoscopists continued a conventional methodology for surveillance. We aimed to investigate the impact of the use of a standard protocol (HD image in WL, FICE assessment and use of 3% AA dye spray, with targeted biopsies and Seattle protocol biopsies) on the detection of all dysplasia and advanced dysplasia (HGD, or in-situ adenocarcinoma). Method We searched the HICCS Endoscopic Reporting System for all endoscopies where Barrett’s oesophagus was detected between October 2010 and October 2014 (n = 587). Only specific surveillance cases were included (index and specific recall cases excluded). Endoscopy reports were checked and histology results retrieved from the Welsh Clinical Portal system. Differences in dysplasia detection rates for the AA Protocol (AA) or ‘standard’ white light endoscopy (WLE) were tested using the Chi-squared test, with significance level set at p Results In the 4 year study period, 367 Barrett’s surveillance procedures were performed in 220 patients. The AA protocol was applied during 86 procedures, standard WLE in 269 procedures. The dysplasia rates are shown in the Table 1. There was a significant increase in the detection rate of all types of dysplasia (p Conclusion Introduction of a Standard AA Protocol in our Health Board was associated with higher detection of dysplasia compared with white light endoscopies performed during the same time interval. The training of a nurse endoscopist to provide this service has proved both feasible and effective. All surveillance patients now attend pre-booked lists where AA protocol is used. Disclosure of interest None Declared.

Advances in the Endoscopic Assessment of Inflammatory Bowel Diseases: Cooperation between Endoscopic and Pathologic Evaluations.

Endoscopic assessment has a crucial role in the management of inflammatory bowel disease (IBD). It is particularly useful for the assessment of IBD disease extension, severity, and neoplasia surveillance. Recent advances in endoscopic imaging techniques have been revolutionized over the past decades, progressing from conventional white light endoscopy to novel endoscopic techniques using molecular probes or electronic filter technologies. These new technologies allow for visualization of the mucosa in detail and monitor for inflammation/dysplasia at the cellular or sub-cellular level. These techniques may enable us to alter the IBD surveillance paradigm from four quadrant random biopsy to targeted biopsy and diagnosis. High definition endoscopy and dye-based chromoendoscopy can improve the detection rate of dysplasia and evaluate inflammatory changes with better visualization. Dye-less chromoendoscopy, including narrow band imaging, iScan, and autofluorescence imaging can also enhance surveillance in comparison to white light endoscopy with optical or electronic filter technologies. Moreover, confocal laser endomicroscopy or endocytoscopy have can achieve real-time histology evaluation in vivo and have greater accuracy in comparison with histology. These new technologies could be combined with standard endoscopy or further histologic confirmation in patients with IBD. This review offers an evidence-based overview of new endoscopic techniques in patients with IBD.

121 Detection of Dysplasia Arising in Barrett's Esophagus Is Improved by Trained Endoscopists With a Specialist Interest on Dedicated Lists

Introduction Barrett’s oesophagus (BE) is the pre-malignant lesion to oesophageal adenocarcinoma (OAC). The presence of dysplasia, when diagnosed in surveillance programmes, is an important marker of risk of progression and an indication for endoscopic therapy. We have previously demonstrated that BE surveillance technique is variable and suggest centralised lists with few highly trained endoscopists. The aim of this study was to assess the introduction of dedicated BE surveillance lists on dysplasia detection rate (DDR). Method Prospective study of patients undergoing BE surveillance at two hospitals – district general hospital (DGH), and tertiary referral upper GI centre. A group of 4 endoscopists (group A) were trained in Prague classification, Seattle protocol biopsy technique and lesion detection. They were nominated to undertake BE surveillance, with dedicated time slots or lists. The DDR was then compared with historical data from 47 different endoscopists at GSTT (group B) and 24 at UHL (Group C) who had undertaken Barrett’s surveillance over the 5 year period. Analysis was by independent t-tests for continuous variables and chi-squared tests for categorical variables. Results A total of 729 patients with BE underwent endoscopy, between 2007 and 2012. Results are shown in Table 1. There was no significant difference in patient’s age, sex or length of BE between the three groups. Of these, 21% (30/144) were diagnosed with dysplasia/EAC by group A endoscopists vs. 9% (55/587) in Group B/C (p = 0.0004). There was a significant difference in detection rate of Indefinite or Low grade dysplasia (IND/LGD) and High grade dysplasia (HGD)/EAC between the 2 groups. There was a significant difference in diagnosis of IND in community (25/271) vs. teaching hospital (5/458) (p = 0.0001). Documentation of length of BE by Prague criteria was significantly higher in group A than group B&C. The use of High Resolution Endoscopy was similar between both groups. Conclusion This study demonstrates that a group of endoscopists trained in BE surveillance, have significantly higher dysplasia detection rate (DDR) than a non specialist cohort. These findings support the argument that BE surveillance, either at DGH or tertiary centre, should only be carried out on dedicated lists by trained endoscopists with a specialist interest. Disclosure of interest None Declared.

Evidence that human papillomavirus causes inverted papilloma is sparse.

Controversy exists regarding the pathogenesis of inverted papilloma as it relates to the involvement of human papillomavirus (HPV). The purpose of this report is to describe the prevalence of HPV in nondysplastic, "early inverted papilloma" and to summarize HPV detection rates in the general population and in other HPV related neoplasia. This case series report characterizes consecutive inverted papilloma patients from January 2005 to August 2012 with regard to smoking history, dysplasia, and HPV detection rates. Presence or absence of low/high risk HPV was determined by standardized in situ hybridization DNA probes. Medline literature review was performed to determine the prevalence of HPV in inverted papilloma without moderate or severe dysplasia. Thirty-six consecutive patients were identified with an average age of 63.6 (range, 40-84) years; gender: 23 men, 13 women. More than half (55%) were active or former smokers (14% active and 41% former). High/low risk HPV was present in 1 in 36 (2.7%) patients and 1 in 36 (2.7%) had mild dysplasia. In the literature review: (1) HPV was detected in 16.4% of inverted papilloma without dysplasia; (2) oral cavity HPV detection was 4.2% to 11.4% in the normal population; and (3) HPV was normally detected in 85% to 95% of HPV-related neoplasia. Given histological features of inverted papilloma and comparatively low detection rates of HPV in inverted papilloma without dysplasia (2.7%), as well as the summary of the world literature, HPV is not related to the initial pathogenesis of inverted papilloma or inverted papilloma's tendency to persist or recur. It is postulated that since inverted papilloma is more an inflammatory polyp, it is susceptible to secondary HPV infection because of its metaplasia. Tobacco and other causes of respiratory epithelium remodeling are more plausible explanations for the initial tissue transformation to inverted papilloma.

Tu1522 Implementing Chromoendoscopy for Surveillance in Inflammatory Bowel Disease Does Not Increase Dysplasia Detection Compared to Conventional Colonoscopy With Random Biopsies: a Retrospective Study

Tu1522 Implementing Chromoendoscopy for Surveillance in Inflammatory Bowel Disease Does Not Increase Dysplasia Detection Compared to Conventional Colonoscopy With Random Biopsies: a Retrospective Study

I-SCAN targeted versus random biopsies in Barrett's oesophagus

The accuracy and effectiveness of targeted oesophageal biopsies in Barrett's oesophagus to detect dysplasia using new magnification techniques are unknown. Aim of this study was to investigate whether the combined use of acetic acid, magnification and electronic filters allows the same accuracy as the four-quadrant random biopsies pattern; pathologist interobserver agreement both in low grade and high grade dysplasia was also assessed. Fifty-four consecutive patients newly diagnosed with Barrett's oesophagus were enrolled in a prospective study from a single endoscopy unit. Biopsies were evaluated by the local pathologist and by an expert pathologist from another pathology unit. Dysplasia detection rate and interobserver agreement for the histologic diagnosis of dysplasia. The use of acetic acid, magnification and electronic filters showed an unacceptably low dysplasia detection rate by the two pathologists (9.2% and 5.5% for targeted biopsies, respectively). The interobserver agreement for low grade dysplasia between pathologists was low (Cohen's K weighted=0.45). In an average setting, the standard four-quadrant method should still be preferred, along with the implementation of a routine second evaluation by an expert pathologist.

Review article: newer optical and digital chromoendoscopy techniques vs. dye‐based chromoendoscopy for diagnosis and surveillance in inflammatory bowel disease

Recent innovations in gastrointestinal endoscopy have changed our traditional approach to diagnosis and therapy in patients with inflammatory bowel diseases (IBD). While traditionally used dye-based chromoendoscopy (DBC) techniques suffer from several limitations that reduce their utility in daily routine practice, newer 'dye-less' chromoendoscopy (DLC) techniques offer a great potential to overcome most of these limitations. To review available optical and digital chromoendoscopy techniques, by critically discussing their potential for diagnostic and surveillance colonoscopy in patients with IBD. A literature search on the use of dye-less and dye-based chromoendoscopy in IBD patients was performed. In long-standing IBD, DBC improves detection of dysplasia (diagnostic odds ratio = 17.5, 95% CI = 1.2-247.1) as well as prediction of inflammatory disease activity and extent of disease compared with standard video-colonoscopy. Narrow band imaging (NBI) shows no improvement in dysplasia detection rates compared with white-light endoscopy and DBC (P = 0.6). Moreover, NBI results in a suboptimal differentiation of dysplastic from nondysplastic lesions. No data regarding digital DLC techniques (i.e. FICE, i-scan) for dysplasia detection in IBD are yet available. Both NBI and i-scan are superior to white-light endoscopy in assessing the activity and extent of colorectal IBD. Although the potential benefits of newer optical and digital dye-less chromoendoscopy techniques over traditionally used DBC are substantial, only DBC can currently be recommended to improve dysplasia detection in long-standing IBD. In contrast, DLC has the potential to quantify disease activity and mucosal healing in IBD.

PTU-025 Diagnostic Yield of a Dedicated Barrett’S Surveillance List using Trimodal Imaging

IntroductionA dedicated endoscopy list for Barrett’s surveillance was introduced at our hospital from 2010. In this study we compared the rate of dysplasia detection and targeted biopsy of this approach...

Procedure Time and the Determination of Polypoid Abnormalities with Experience

Procedure length and agreement in detection of abnormalities may limit implementation of chromoendoscopy (CE) for dysplasia surveillance in ulcerative colitis (UC). We investigated these factors among endoscopists inexperienced in this technique. Six investigators performed surveillance colonoscopy with white light endoscopy (WLE) followed by CE on 75 patients with long-standing UC. Interobserver agreement for WLE and CE images of polyps and nonpolypoid mucosa was determined. Withdrawal times from the cecum were compared based on number of colonoscopies performed. Dysplasia detection rate with WLE was compared with CE. The analysis of 586 images (266 WLE and 320 CE) from 57 patients included images of 160 polyps (64 flat) with 29 dysplastic lesions. All investigators identified 10/11 WLE images of dysplasia and 4 identified all 18 CE dysplasia images, 1 missed 1 and 1 missed 3. Four dysplastic lesions were not identified by 1 or more investigators and all measured <5 mm. Interobserver agreement for lesions was high with kappa scores of 0.91 and 0.86 for WLE and CE, respectively. Among the 75 patients enrolled, dysplasia was found in 9.3% with WLE compared with 21.3% with WLE and CE (P = 0.007). Median colonoscopy withdrawal time improved from 31 minutes for endoscopists performing fewer than 5 procedures to 18 minutes for 5 to 14 and 19 minutes for more than 15 procedures. Indigo carmine CE for UC surveillance resulted in high rates of interobserver agreement for polyp detection, acceptable withdrawal times, and enhanced dysplasia detection. These results are encouraging for the implementation of CE programs for chronic UC.

Caveat Emptor: Submitting the Entire Gallbladder in Cases of Dysplasia Is Not JustifiedThe Authors’ Reply

To the Editor We read with interest the article by Renshaw and Gould.1 The authors present a very important topic for discussion, namely, the appropriate tissue sampling of a common specimen, the gallbladder. The authors express their frustrations with expert recommendations of a consultant to submit the entire gallbladder when cases have been sent out for second opinion from their practice. The authors cite their own 8-year practice of submitting 2 sections (1 section from the cystic duct and 1 random section) for the initial evaluation of gallbladders. They conclude that in cases of epithelial atypia and dysplasia, a review of the gross specimen and the submission of “4 more additional sections” is sufficient. Although we support the judicious submission of gallbladders, some deficiencies in this article need to be highlighted. The authors report a detection rate of dysplasia in cholecystectomy specimens of 0.15%, which is lower than the lowest reported frequency of solitary dysplasia or incidentally detected dysplasia of 0.4% to 33.8%.2 This low detection rate may be caused by sampling as suggested by Sasatomi et al2 and Duarte et al3 that a single random histologic section would detect less than …

Dysplasia detection rate of confirmatory EGD in nondysplastic Barrett's esophagus

Current guidelines for endoscopic surveillance of Barrett's esophagus (BE) recommend that patients with newly diagnosed BE undergo confirmatory esophagogastroduodenoscopy (EGD) to exclude the presence of dysplasia. The extent to which confirmatory endoscopy alters management and detects missed dysplasia in newly diagnosed BE has not been reported. The frequency with which confirmatory endoscopy changed surveillance management in patients with newly diagnosed BE was assessed. A two center cohort analysis was conducted on patients newly diagnosed with BE. The rate of dysplasia on confirmatory endoscopy for patients who had nondysplastic BE was obtained. Demographic and endoscopic variables were assessed for association with dysplasia detection using Firth logistic regression model. Out of the 146 patients newly diagnosed with BE and initially determined to be without dysplasia, 12 had dysplasia on the confirmatory second EGD (8.2%). Eleven of 12 cases with dysplasia on confirmatory endoscopy had long-segment BE (LSBE). Among all the LSBE cases in our cohort, 11 had newly diagnosed dysplasia on confirmatory EGD, 29.7% (11/37). The average number of biopsies obtained from the 11 LSBE cases with dysplasia was comparable with the rest of the LSBE cases without dysplasia (6.73 and 5.42, respectively, P-value 0.205). The rate of dysplasia detection in short-segment BE (SSBE) was much lower, 0.95% (1 out of 105). There were no cases of high-grade dysplasia (HGD) or cancer detected in any SSBE case. HGD was detected on confirmatory EGD in two cases, both were LSBE. Segment length was the only statistically significant factor to predict the presence of dysplasia on confirmatory endoscopy (odds ratio 9.158, P. 0.008). Confirmatory EGD in newly diagnosed LSBE had significant rate of dysplasia detection (29.7%) in this cohort. Among patients with SSBE, there was a low rate of dysplasia detection with confirmatory EGD, less than 1% of cases. No additional cases of HGD or esophageal carcinoma in SSBE cases were detected. This suggests that the yield of confirmatory EGD is greater in patients with LSBE.

Improved Detection of Incident Dysplasia by Probe-Based Confocal Laser Endomicroscopy in a Barrett’s Esophagus Surveillance Program

Probe-based confocal laser endomicroscopy (pCLE) is a new technique allowing in vivo detection of neoplastic tissue using a standard endoscope. Our aim was to compare the incident dysplasia detection rate of biopsies obtained by high-definition white light endoscopy (HD-WLE) or by pCLE in a cohort of patients with Barrett's esophagus (BE) participating in a surveillance program. Fifty of 100 patients underwent pCLE in addition to HD-WLE. Four-quadrant biopsy specimens according to the Seattle biopsy protocol were obtained in all patients to ensure standard-of-care. Diagnosis of dysplasia/neoplasia was made by a blinded gastrointestinal pathologist. Incident high-grade dysplasia (HGD) and low-grade dysplasia (LGD) were diagnosed in 3/100 and in 16/100 cases. In the HD-WLE group, areas suspicious for neoplasia were not observed and dysplasia was diagnosed in 5/50 (10%) patients (one with HGD). In the pCLE group, areas suspicious for neoplasia were observed by pCLE in 21/50 (42%) patients; dysplasia was confirmed in 14 cases (28%) (two with HGD). The dysplasia detection rate was significantly higher in the pCLE group than in the HD-WLE group (P = 0.04). The sensitivity, specificity, positive and negative predictive values of pCLE for dysplasia were 100, 83, 67, and 100%, respectively. Incident dysplasia can be more frequently detected by pCLE than by HD-WLE in BE. The higher dysplasia detection rate provided by pCLE could improve the efficacy of BE surveillance programs.

Unveiling Cancer in IBD: Screening Colonoscopy or Chromoendoscopy

The risk of developing colorectal cancer (CRC) is increased in patients with inflammatory bowel disease (IBD), particularly if the disease is extensive and its duration long-standing. Endoscopic guidelines have been developed with the goal of detecting early neoplastic changes prior to development of advanced malignancy. The current surveillance strategy of surveillance colonoscopy, with multiple random biopsies, most likely reduces morbidity and mortality associated with IBD-related CRC. Unfortunately, standard surveillance colonoscopy also has limitations, including high cost and sampling error at time of biopsy. The main issue is that colitis associated neoplasms often occur in flat mucosa of normal appearance, and are detected on taking random biopsies rather than by direct identification of these lesions via endoscopic imaging. Advances in endoscopic imaging techniques, such as vital or optical chromoendoscopy, that can enhance mucosal characteristics, may potentially aid in increasing dysplasia detection rate, and may reduce the workload of standard random biopsies. The aim of this review was to describe and summarize outcomes of more advanced endoscopic imaging techniques, including chromoendoscopy and magnification endoscopy.

PTU-207 Detection of dysplasia arising in Barrett's oesophagus is associated with better quality endoscopic technique

IntroductionBarrett's columnar lined oesophagus (CLO) is the pre-malignant lesion to oesophageal adenocarcinoma (OAC). The presence of dysplasia, when diagnosed in surveillance programmes, is an important marker of risk of progression...

Longer Barrett's Inspection Time (Bit) is Associated With a Higher Detection Rate of High Grade Dysplasia (HGD) and Early Esophageal Adenocarcinoma (EAC)

Longer Barrett's Inspection Time (Bit) is Associated With a Higher Detection Rate of High Grade Dysplasia (HGD) and Early Esophageal Adenocarcinoma (EAC)

Brush cytology vs. endoscopic biopsy for the surveillance of Barrett’s esophagus

Periodic surveillance with systematic biopsies is recommended for patients with Barrett's esophagus. Brush cytology has been proposed as a simple inexpensive component of endoscopic surveillance, which may also detect abnormalities prior to detection of histologic abnormalities. The aim of the current study was to determine whether brush cytology provides any additional value over endoscopic surveillance biopsies in patients with Barrett's esophagus. This retrospective cohort study included 530 patients with Barrett's esophagus undergoing endoscopic surveillance with paired biopsy and cytology specimens at the Cleveland Clinic between January 1994 and July 2008. The main outcome measures were sensitivity, specificity, and concordance rates of cytology and histology. Sensitivity of cytology for any dysplasia was 49 % and specificity was 95 %. However, sensitivity was 82 % for detection of high grade dysplasia/adenocarcinoma but only 31 % for low grade/indefinite for dysplasia. The concordance rate between cytology and histology was 80 %. Histology had a higher dysplasia detection rate than cytology (24.0 % vs. 15.7 %, respectively; P <0.0001). Cytology has excellent specificity and good sensitivity for the detection of high grade dysplasia/adenocarcinoma but poor sensitivity for low grade dysplasia. There was substantial concordance between cytology and histology for the detection of dysplasia. However, histology had a higher dysplasia detection rate and therefore the value of routine cytology in the surveillance of Barrett's esophagus is questionable.

Abstract CN06-04: Optical coherence tomography imaging of preneoplastic lung lesion

Abstract Although autofluorescence bronchoscopy improves the detection rate of high grade dysplasia and carcinoma in-situ compares to white-light examination, the natural history of preneoplastic bronchial lesions is still poorly understood because the biopsy procedure for histological confirmation can mechanically remove these small lesions. The lack of accurate information regarding the spontaneous progression and regression rates of preneoplastic lesions make if difficult to assess the effect of chemoprevention agents. It is therefore important to develop non-biopsy methods that can characterize preneoplastic lesions in the bronchial epithelium. Optical coherence tomography (OCT) is an optical imaging method that can visualize cellular and extra-cellular structures at and below tissue surface. In principle, it is similar to B-type ultrasound. Instead of using sound waves, a low coherence near infra-red light such as from a broadband 1300 nm superluminescent diode source is passed into the tissue. By detecting the reflected light as it interacts with tissue structures as a function of depth, a cross sectional image is created through optical interferometry. Its contrast is the backscattered light from interfaces at different depths in the tissue, due to the heterogeneity of optical refractive indices from different tissue compositions and densities. Changes in the extracellular matrix can be readily seen due to the strong back-scattering properties of collagen and elastin. OCT provides cross-sectional tomographic images about anatomic layered structures of tissues with a large field-of-view, a spatial resolution of 3 to 16 microns and a depth penetration of 2 – 3 mm to provide near-histological images. The imaging procedure is performed using fiber optic probes that can be miniaturized to enable imaging of airways down to the terminal bronchiole. Unlike ultrasound, light waves do not require liquid based coupling medium and thus are more compatible with airway imaging. There are no associated risks from the weak near infrared light. OCT has distinct advantages over CT and MRI for imaging small airways in-vivo in that it has superior resolution approaching near-microscopic resolution and requires no ionizing radiation. It has advantages over confocal microscopy in that it can penetrate tissue three times deeper, does not require contact with the tissue surface and is less susceptible to motion artifacts due to real-time image acquisition. In addition to morphometric information, functional OCT, such as Doppler OCT, can also provide quantitative information on blood flow of blood vessels and micro-vasculature. OCT imaging has been applied to study bronchial and lung tissues and has been shown to be promising in the detection and characterization of preneoplastic lesions tumor in central and peripheral airways. Citation Information: Cancer Prev Res 2010;3(1 Suppl):CN06-04.