Surveying the case for surveillance

Benefits of the Seattle biopsy protocol in the diagnosis of Barrett’s esophagus in a Chinese population

AIM

To investigate the benefits of the Seattle protocol in the diagnosis of Chinese individuals with Barrett’s esophagus.

METHODS

Subjects enrolled were patients from one center with endoscopically-suspected esophageal metaplasia. These patients first received narrow-band imaging-targeted biopsy, and later, the Seattle protocol-guided biopsy, within a period from October 2012 to December 2014. Those cases without initial pathologic patterns of intestinal metaplasia (IM) and then appearance or loss of IM tissue were designated as Group A or B, respectively. Those with initial pathologic patterns of IM, which then persisted or were lost were designated as Group C or D, respectively.

RESULTS

The number of cases for each group was as follows: A: 20, B: 78, C: 31 and D: 14. The distribution of the Prague criteria M levels of Group A was significantly higher than Group B (P = 0.174). Among these groups, Group C had the highest proportions of hiatus hernia (54.8%), long segment Barrett’s esophagus (29%), and also the highest Prague criteria M levels. The sensitivity of IM detection was 69.2% for the narrow-band imaging-targeted biopsy and 78.5% for the Seattle protocol-guided biopsy. The difference was not significant (P = 0.231). The number of detectable dysplasias increased from one case via the NBI-target biopsy to five cases via the Seattle protocol-guided biopsy, including one case of adenocarcinoma.

CONCLUSION

The Seattle protocol improved the IM detection in our subjects with higher Prague criteria M levels and disclosed more cases with dysplastic tissues.

Advances in the Endoscopic Diagnosis of Barrett Esophagus

BACKGROUND

Barrett esophagus (BE) continues to be a major risk factor for developing esophageal adenocarcinoma.

METHODS

We review the risk factors, diagnosis, and management of BE, with an emphasis on the most current endoscopic diagnostic modalities for BE.

RESULTS

Novel diagnostic modalities have emerged to address the inadequacies of standard, untargeted biopsies, such as dye-based and virtual chromoendoscopy, endoscopic mucosal resection, molecular biomarkers, optical coherence tomography, confocal laser endomicroscopy, volumetric laser endomicroscopy, and endocytoscopy. Treatment of BE depends on the presence of intramucosal cancer or dysplasia, particularly high-grade dysplasia with or without visible mucosal lesions.

CONCLUSIONS

Recent advances in endoscopic diagnostic tools demonstrate promising results and help to mitigate the shortcomings of the Seattle protocol. Future research as well as refining these tools may help aid them in replacing standard untargeted biopsies.

Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study

BACKGROUND

Biopsy surveillance protocols for the assessment of Barrett's esophagus can be subject to sampling errors, resulting in diagnostic uncertainty. Optical coherence tomography is a cross-sectional imaging technique that can be used to conduct volumetric laser endomicroscopy (VLE) of the entire distal esophagus. We have developed a biopsy guidance platform that places endoscopically visible marks at VLE-determined biopsy sites.

OBJECTIVE

The objective of this study was to demonstrate in human participants the safety and feasibility of VLE-guided biopsy in vivo.

DESIGN

A pilot feasibility study.

SETTING

Massachusetts General Hospital.

PATIENTS

A total of 22 participants were enrolled from January 2011 to June 2012 with a prior diagnosis of Barrett's esophagus. Twelve participants were used to optimize the laser marking parameters and the system platform. A total of 30 target sites were selected and marked in real-time by using the VLE-guided biopsy platform in the remaining 10 participants.

INTERVENTION

Volumetric laser endomicroscopy.

MAIN OUTCOME MEASUREMENTS

Endoscopic and VLE visibility, and accuracy of VLE diagnosis of the tissue between the laser cautery marks.

RESULTS

There were no adverse events of VLE and laser marking. The optimal laser marking parameters were determined to be 2 seconds at 410 mW, with a mark separation of 6 mm. All marks made with these parameters were visible on endoscopy and VLE. The accuracies for diagnosing tissue in between the laser cautery marks by independent blinded readers for endoscopy were 67% (95% confidence interval [CI], 47%-83%), for VLE intent-to-biopsy images 93% (95% CI, 78%-99%), and for corrected VLE post-marking images 100% when compared with histopathology interpretations.

LIMITATIONS

This is a single-center feasibility study with a limited number of patients.

CONCLUSION

Our results demonstrate that VLE-guided biopsy of the esophagus is safe and can be used to guide biopsy site selection based on the acquired volumetric optical coherence tomography imaging data. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01439633.).

In vivo optical coherence tomography: the role of the pathologist

Optical coherence tomography (OCT) is a nondestructive, high-resolution imaging modality, providing cross-sectional, architectural images at near histologic resolutions, with penetration depths up to a few millimeters. Optical frequency domain imaging is a second-generation OCT technology that has equally high resolution with significantly increased image acquisition speeds and allows for large area, high-resolution tissue assessments. These features make OCT and optical frequency domain imaging ideal imaging techniques for surface and endoscopic imaging, specifically when tissue is unsafe to obtain and/or suffers from biopsy sampling error. This review focuses on the clinical impact of OCT in coronary, esophageal, and pulmonary imaging and the role of the pathologist in interpreting high-resolution OCT images as a complement to standard tissue pathology.

Comprehensive microscopy of the esophagus in human patients with optical frequency domain imaging

BACKGROUND

Optical coherence tomography (OCT) is a cross-sectional, high-resolution imaging modality that has been shown to accurately differentiate esophageal specialized intestinal metaplasia (SIM) from gastric cardia at the squamocolumnar junction (SCJ) and diagnose high-grade dysplasia and intramucosal carcinoma in patients with SIM. The clinical utility of OCT has been limited, however, by its inability to acquire images over large areas.

OBJECTIVE

The aim of this study was to use recently developed high-speed OCT technology, termed optical frequency domain imaging (OFDI), and a new balloon-centering catheter (2.5 cm diameter) to demonstrate the feasibility of large area, comprehensive optical microscopy of the entire distal esophagus (approximately 6.0 cm) in patients.

DESIGN

A pilot feasibility study.

SETTING

Massachusetts General Hospital.

PATIENTS

Twelve patients undergoing routine EGD.

RESULTS

Comprehensive microscopy of the distal esophagus was successfully performed in 10 patients with the OFDI system and balloon catheter. There were no complications resulting from the imaging procedure. Volumetric data sets were acquired in less than 2 minutes. OFDI images at the SCJ showed a variety of microscopic features that were consistent with histopathologic findings, including squamous mucosa, cardia, SIM with and without dysplasia, and esophageal erosion.

LIMITATIONS

Inability to obtain direct correlation of OFDI data and histopathologic diagnoses.

CONCLUSIONS

Comprehensive volumetric microscopy of the human distal esophagus was successfully demonstrated with OFDI and a balloon-centering catheter, providing a wealth of detailed information about the structure of the esophageal wall. This technique will support future studies to compare OFDI image information with histopathologic diagnoses.

Should patients with Barrett's oesophagus be kept under surveillance? The case for

Oesophageal adenocarcinoma is associated with high mortality rates and its incidence is increasing more rapidly than any other gastrointestinal cancer in the Western world. Several factors, including gastro-oesophageal reflux disease, smoking, alcohol and male gender, are associated with oesophageal adenocarcinoma but none can be used to identify accurately those individuals who will develop adenocarcinoma. It is generally accepted that oesophageal adenocarcinoma arises predominantly in Barrett's oesophagus and it is arguable that Barrett's oesophagus is currently the only clinically useful predictor of oesophageal adenocarcinoma. Surveillance - periodic testing to detect adenocarcinoma or its precursor, high grade dysplasia - is widely recommended for patients with Barrett's oesophagus with the aim of reducing mortality from oesophageal adenocarcinoma. The annual incidence of oesophageal adenocarcinoma in patients with Barrett's oesophagus is 0.5%-1.0% although there is marked variation between studies, attributable variously to publication bias, concurrent acid suppression therapy and differences in patient characteristics. There is limited evidence that surveillance reduces the incidence of oesophageal adenocarcinoma or consequent mortality and the cause of death for patients undergoing surveillance is often unrelated to oesophageal disease. There are, nonetheless, observational studies which suggest that surveillance is associated with earlier detection of malignancy and a reduction in mortality; in addition, data from modelling studies suggest that surveillance can be cost-effective. Furthermore, the advent of new, non-surgical treatments (endoscopic mucosal resection, photodynamic therapy, argon plasma coagulation) for high grade dysplasia and early cancer has reduced the risks associated with therapy for disease detected during surveillance. Surveillance programs have high drop out rates and, for patients who continue surveillance, adherence to standard, published protocols is highly variable. The establishment of specialist Barrett's oesophagus surveillance programs, with coordinator support, has considerable potential to improve adherence to current guidelines, pending the acquisition and publication of data from ongoing studies of chemoprophylaxis and surveillance in the management of Barrett's oesophagus. In consequence, although there is a paucity of data providing unequivocal demonstration of benefit, there is no proof that surveillance is ineffective. It is, therefore, appropriate to offer surveillance for Barrett's oesophagus in accordance with locally-applicable published guidelines after a full informed discussion of the risks and benefits of surveillance and therapy; continued participation should be reviewed regularly to accommodate changes in the patient's health and expectations.

Modelling a population with Barrett's oesophagus from oesophageal adenocarcinoma incidence data

OBJECTIVE

A recent study of adenocarcinoma of the oesophagus (ACO) incidence rates in Denmark showed a steep fall in the over-80 population, interpreted as the result of a decline in the prevalence of Barrett's oesophagus (BO) in this age group, for which three hypotheses were advanced: the specific mortality from ACO and, superimposed, either excess mortality from causes of death unrelated to ACO or a birth cohort effect. The aim of this study was to create models estimating the BO population fitting each of these three hypotheses, in order to select the most plausible hypothesis and to gain insight into the Danish BO population.

MATERIAL AND METHODS

Models were designed for these three hypotheses, conforming to the generally accepted 0.4-0.5% annual ACO incidence in BO patients. These models employed expectation-maximization (EM) algorithms, Danish life tables and the observed ACO incidence rates. The models enabled the estimation of a BO population for each hypothesis.

RESULTS

After testing against set criteria, the most plausible model was found to be that describing a birth cohort effect which predicted a +/-5% annual rise in the prevalence of BO and, consequently, in the incidence rate of ACO in Denmark. This prediction was borne out over the subsequent decade.

CONCLUSIONS

This rising ACO incidence rate is likely to continue into the foreseeable future. The use of EM algorithms enabled a first estimate of the BO population at risk of ACO, although, owing to the limitations imposed by the models, the age- and gender-specific ACO risk for the entire Danish BO population could not as yet be ascertained.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

The use of optical coherence tomography in screening and surveillance of Barrett's esophagus

Barrett's esophagus (BE) is defined as the presence of specialized intestinal metaplasia within the tubular esophagus. Recent studies suggest that performing endoscopic surveillance in patients with Barrett's esophagus is effective in preventing esophageal adenocarcinoma at an early stage. However, the accuracy of surveillance endoscopy is limited by sampling error and cost. Optical coherence tomography (OCT) is an optical analog of ultrasound, providing 10-microm resolution and real-time cross-sectional images of the luminal gastrointestinal tract. The literature describing the use of OCT in models of dysplasia and BE are reviewed. Three studies have examined the use of OCT in BE and models of dysplasia. These studies suggest that the currently achievable resolution combined with light-scattering properties of Barrett's mucosa is adequate to discern intestinal metaplasia and reliably detect high-grade dysplasia in patients with BE. Additional research to validate these findings is required.

Dysplasia and risk of further neoplastic progression in a regional Veterans Administration Barrett's cohort

OBJECTIVES

No published data are available on the risk of further neoplastic progression in Barrett's patients stratified by baseline dysplasia status. Our aims were to estimate and compare the risk of progression to high-grade dysplasia or cancer in groups of Barrett's patients stratified by baseline dysplasia status.

METHODS

Consecutive Barrett's cases from 1988-2002 were identified via pathology databases in a regional VA health-care system and medical record data were abstracted. The risk of progression to high-grade dysplasia or cancer was measured and compared in cases with versus without low-grade dysplasia within 1 yr of index endoscopy using survival analysis.

RESULTS

A total of 575 Barrett's cases had 2,775 patient-years of follow-up. There were 13 incident cases of high-grade dysplasia and two of cancer. The crude rate of high-grade dysplasia or cancer was 1 of 78 patient-years for those with baseline dysplasia versus 1 of 278 patient-years for those without (p= 0.001). One case of high-grade dysplasia in each group underwent successful therapy. One incident cancer case underwent successful resection and the other was unresectable. Two cases with high-grade dysplasia later developed cancer, one died postoperatively, the other was unresectable. When these two cases were included (total of four cancers), the crude rate of cancer was 1 of 274 patient-years for those with baseline dysplasia versus 1 of 1,114 patient-years for those without.

CONCLUSIONS

In a large cohort study of Barrett's, incident malignancy was uncommon. The rate of progression to high-grade dysplasia or cancer was significantly higher in those with baseline low-grade dysplasia. These data may warrant reevaluation of current Barrett's surveillance strategies.

Oesophageal cancer incidence and mortality in patients with long-segment Barrett's oesophagus after a mean follow-up of 12.7 years

BACKGROUND

Data on cancer risk in patients with long-segment Barrett's oesophagus (BO) from older studies are often difficult to interpret, since the definition of BO has evolved from an endoscopical to a histological diagnosis. In this work the diagnoses in the Rotterdam BO cohort on current standards was redefined to obtain more accurate data on cancer risk in patients who had not undergone standard endoscopic surveillance. In addition, it was determined which patient factors present at index endoscopy were associated with neoplastic progression in BO.

METHODS

The Rotterdam BO cohort comprises all patients with > or =3 cm BO, diagnosed at endoscopy between 1973 and 1984. In the present study, only patients with intestinal metaplasia were included (n = 105). Follow-up data were obtained by questionnaires and/or interviews with patients or treating physicians. A Kaplan-Meier analysis was used to estimate 20-year risks.

RESULTS

The mean length of the BO was 7.1 cm (range: 3-15 cm). Cancer in BO developed in 6/105 (6%) patients, and high-grade dysplasia (HGD) in 5/105 (5%) patients during 1329 patient-years of follow-up, which equals one cancer case per 221 patient-years and one HGD case per 266 patient-years. After a mean follow-up of 12.7 years, 72 (69%) patients had died; only 4 of them died of oesophageal cancer or its treatment. A longer length of BO was associated with an increased risk of progression to HGD or cancer (P < 0.02). Six of 24 patients who ever had low-grade dysplasia progressed to HGD or cancer 2-16 years after a diagnosis of BO.

CONCLUSIONS

The annual risk of developing HGD or adenocarcinoma in patients with long-segment BO is 0.83%. Death due to adenocarcinoma is, however, uncommon, even in a cohort of patients with long-segment BO.

Effect of surveillance of Barrett's oesophagus on the clinical outcome of oesophageal cancer

BACKGROUND

Surveillance programmes for Barrett's oesophagus have been implemented in an effort to detect oesophageal adenocarcinoma at an earlier and potentially curable stage. The aim of this study was to examine the impact of endoscopic surveillance on the clinical outcome of patients with adenocarcinoma complicating Barrett's oesophagus.

METHOD

Consecutive patients who underwent oesophageal resection for high-grade dysplasia or adenocarcinoma arising from Barrett's oesophagus were studied retrospectively. The pathological stage and survival of patients identified as part of a surveillance programme were compared with those of patients presenting with symptomatic adenocarcinoma.

RESULTS

Seventeen patients in the surveillance group and 74 in the non-surveillance group underwent oesophagectomy. Disease detected in the surveillance programme was at a significantly earlier stage: 13 of 17 versus 11 of 74 stage 0 or I, three versus 26 stage II, and one versus 37 stage III or IV (P < 0.001). Lymphatic metastases were seen in three of 17 patients in the surveillance group and 42 of 74 who were not under surveillance (P = 0.004). Three-year survival was 80 and 31 per cent respectively (P = 0.008).

CONCLUSION

Patients with surveillance-detected adenocarcinoma of the oesophagus are diagnosed at an earlier stage and have a better prognosis than those who present with symptomatic tumours.

Screening for esophageal luminal narrowing--a magnetic disc tablet as a bolus challenge: preliminary report

Narrowing of the esophageal lumen often exists for months before being noted by the patient. Screening tests for such lesions would be useful, if applicable to office use. A magnetic disc tablet (14 mm in diameter and 5 mm thick) was fashioned by hand using dental acrylic material to enclose the magnet with a smooth watertight sheath. A magnetic detector was held on the anterior abdominal wall 2.5 cm below the xiphoid cartilage and 2.5 cm to its left. A significant change in reading indicated that the tablet had reached the cardia of the stomach. The magnetic tablet was readily detected in 11 patients without organic narrowing. Our method attempts to detect narrowing of the esophageal lumen by use of a magnetic disc tablet. Perhaps this will be of clinical usefulness in detecting esophageal disease before symptoms become apparent.

A case-control study of endoscopy and mortality from adenocarcinoma of the esophagus or gastric cardia in persons with GERD

BACKGROUND

This study assessed whether EGD reduces mortality from adenocarcinoma of the esophagus or gastric cardia for patients with gastroesophageal reflux.

METHODS

A case-control study was performed. A total of 245 incident cases of death caused by adenocarcinoma of the esophagus or gastric cardia (1995-1999) in which reflux was present were identified using Veterans Health Administration databases. A total of 980 controls with reflux but no death from adenocarcinoma were frequency matched for age, gender, and race. The occurrences of EGD from 1990 onward were compared for cases and controls. Logistic regression analysis with adjustment for potential confounding factors was performed.

RESULTS

All the subjects were men. Cases were significantly less likely to have had an EGD in the time period of interest as compared with controls (adjusted odds ratio 0.66: 95% CI [0.45, 0.96], p = 0.03). This negative association was as strong for any EGD performed within 1 to 8 years before diagnosis as for a more recent EGD. However, there were no controls that included esophagectomy and no controls with a nonfatal diagnosis of adenocarcinoma, raising the question of whether EGD and reduced mortality are causally linked. The risk of dying from adenocarcinoma was significantly lower for men with a diagnosis of GERD as an inpatient relative to men in whom the diagnosis was made as an outpatient (adjusted odds ratio 0.21: 95% CI [0.15, 0.31], p < 0.01).

CONCLUSIONS

For patients with GERD, performing an EGD is associated with reduced mortality from adenocarcinoma of the esophagus or gastric cardia, but whether this is a causative association remains unclear.