Long-term follow-up of Barrett's high-grade dysplasia

Reprimo methylation is a potential biomarker of Barrett's-Associated esophageal neoplastic progression

PURPOSE

Reprimo, a candidate tumor-suppressor gene, regulates p53-mediated cell cycle arrest at G2 phase, and tumor-suppressor gene methylation is involved in the pathogenesis and progression of esophageal cancer. Our aim was to determine whether and at what phase of neoplastic progression Reprimo methylation occurs in Barrett's adenocarcinogenesis, as well as its columnar or squamous cell-type specificity. We also sought to determine whether Reprimo expression could be restored in vitro by the demethylating agent 5-aza-deoxycytidine (5AzaC).

EXPERIMENTAL DESIGN

Quantitative methylation-specific PCR for Reprimo was done using an ABI7700 (Taqman) apparatus on 175 endoscopic biopsy specimens. In addition, reverse transcription-PCR and quantitative methylation-specific PCR were done on esophageal carcinoma cells before and after treatment with 5AzaC.

RESULTS

In Barrett's esophagus (BE; P=0.001), high-grade dysplasia (HGD; P=0.001), and esophageal adenocarcinoma (EAC; P=0.00003), the level and frequency of Reprimo methylation were significantly higher than in normal esophagus (NE). There was no statistically significant difference between BE and EAC, HGD and EAC, or NE and esophageal squamous cell carcinoma (ESCC). Reprimo methylation occurred in 0 of 19 NE samples, 6 (13%) of 45 ESCC, 9 (36%) of 25 BE, 7 (64%) of 11 HGD, and 47 (63%) of 75 EAC. Analysis of Reprimo methylation in EAC versus NE revealed an area under the receiver-operator characteristic curve of 0.812 (P<0.00001; 95% confidence interval, 0.73-0.90). In vitro 5AzaC treatment of OE33 EAC cells reduced Reprimo methylation and increased Reprimo expression.

CONCLUSIONS

Reprimo methylation occurs significantly more frequently in BE, HGD, and EAC than in NE or ESCC, suggesting that this epigenetic alteration is a specialized columnar, cell-specific early event with potential as a biomarker for the early detection of esophageal neoplasia.

Cyclin A immunocytology as a risk stratification tool for Barrett's esophagus surveillance

PURPOSE

Endoscopic surveillance of Barrett's esophagus (BE) by histopathologic biopsy assessment is suboptimal. A proliferation marker, minichromosome maintenance protein 2, has potential as a biomarker but lacks specificity. We hypothesized that cyclin A, which detects a proportion of proliferating cells, would be more specific. Because cytologic sampling has clinical advantages, we also evaluated the efficacy of cyclin A in endoscopic brushing samples.

EXPERIMENTAL DESIGN

A cross-sectional cyclin A immunostaining study was done in 77 patients attending for BE surveillance and 17 patients undergoing evaluation of esophageal adenocarcinoma. The control tissues were as follows: 30 squamous esophagus, 20 gastric antrum, and 13 duodenum. A nested case-control study was done within the same surveillance cohort (16 progressors compared with 32 matched controls) to determine the relative risk for progression. Immunocytology was done for endoscopic brushings collected prospectively from 75 BE +/- dysplasia and 33 esophageal adenocarcinomas.

RESULTS

Surface expression of cyclin A in BE samples correlated with the degree of dysplasia (P = 0.016). In the case-control cohort, patients with biopsies expressing cyclin A at the surface were more likely to progress to adenocarcinoma than those who did not (odds ratio, 7.5; 95% confidence interval, 1.8-30.7). The sensitivity and specificity of cyclin A expression in brushings for the detection of high-grade dysplasia and cancer patients were 97.8% and 58.7%, respectively. The associated negative predictive value was 97.4%.

CONCLUSIONS

Cyclin A immunopositivity correlates with cancer risk. Application of this marker to endoscopic brushings could be used as a first step to identify BE patients with the highest risk of progression.

Barrett's oesophagus?a pathologist's view

Barrett's oesophagus, a precancerous condition for oesophageal adenocarcinoma, detected on endoscopy and confirmed on histology, shows intestinal metaplasia of the lower oesophagus. The significance of microscopic foci of intestinal metaplasia at the gastro-oesophageal junction, corresponding either to so-called 'ultrashort' segment Barrett's oesophagus, or to carditis with intestinal metaplasia, is still a matter of debate. The surveillance of patients with Barrett's oesophagus is still based on systematic biopsy sampling of Barrett's mucosa on endoscopy, looking for dysplasia. Although well-established classifications of dysplasia are now used by most pathologists, there remain numerous problems with this subjective marker (sampling, diagnostic reproducibility, natural history, etc). Therefore, many alternative biomarkers have been proposed, but only DNA aneuploidy, proliferation markers and p53 loss of heterozygosity/overexpression have been shown to be of some use at the present time. Some endoscopic improvements already allow a better selection of biopsies, and it may be that in future new technologies will allow 'virtual biopsies'. On the other hand, the role of pathologists now extends to the evaluation of new therapeutic modalities of early neoplastic lesions in Barrett's oesophagus, especially endoscopic mucosal resection.

Does cancer risk affect health-related quality of life in patients with Barrett's esophagus?

BACKGROUND

Health-related quality of life is decreased in patients with GERD and Barrett's esophagus (BE).

OBJECTIVE

To determine whether time-tradeoff (TTO) values would differ in patients with BE when patients were asked to trade away the potential risk of esophageal adenocarcinoma rather than chronic heartburn symptoms.

DESIGN

A prospective clinical trial.

PATIENTS

Subjects with biopsy-proven BE.

INTERVENTIONS

Custom-designed computer program to elicit health-state utility values, quality of life in reflux and dyspepsia (QOLRAD), and Medical Outcomes Survey short form-36 surveys.

MAIN OUTCOME MEASUREMENTS

TTO utility values for the annual cancer-risk-associated current health state and for hypothetical scenarios of dysplasia and esophageal cancer.

RESULTS

We studied 60 patients in the cancer-risk cohort (57 men, 92% veteran; mean age [standard deviation; SD], 65 years [11 years], mean GERD duration 17 years [12 years]). The heartburn cohort included 40 patients with GERD and BE with TTO values derived for GERD symptoms. The mean (SD) utility for nondysplastic BE was 0.91 (0.13) compared with 0.90 (0.12) for the heartburn cohort (P = .7). The mean utility values were significantly lower for scenarios of low-grade dysplasia (0.85 [0.12], P = .02) and high-grade dysplasia (0.77 [0.14], P < .005). The mean TTO was 0.67 (0.19) for the scenario of esophageal cancer. There was no correlation between the utility scores and the disease-specific survey scores.

LIMITATIONS

TTO values were hypothetical for states of dysplasia and cancer.

CONCLUSIONS

TTO utility values based on heartburn symptoms or annual risk of cancer in patients with nondysplastic BE are roughly equivalent. However, TTO utility values are significantly lower for health states with increasing cancer risks.

Endoscopic ablation of intestinal metaplasia containing high-grade dysplasia in esophagectomy patients using a balloon-based ablation system

BACKGROUND

This study aimed to determine the optimal treatment parameters for the ablation of intestinal metaplasia (IM) containing high-grade dysplasia (HGD) using a balloon-based ablation system for patients undergoing esophagectomy.

METHODS

Immediately before esophagectomy, patients underwent ablation of circumferential segments of the esophagus containing IM-HGD using the HALO360 system. The treatment settings were randomized to 10, 12, or 14 J/cm2 for two, three, or four applications. After esophagectomy, multiple sections from ablation zones were microscopically evaluated. Histologic end points included maximum ablation depth (histologic layer) and complete ablation of all IM-HGD (yes/no).

RESULTS

Eight men with a mean age of 57 years (range, 45-71 years) were treated, and 10 treatment zones were created. There were no device-related adverse events. At resection, there was no evidence of a transmural thermal effect. Grossly, ablation zones were clearly demarcated sections of ablated epithelium. The maximum ablation depth was the lamina propria or muscularis mucosae. The highest energy (14 J/cm2, 4 applications) incurred edema in the superficial submucosa, but no submucosa ablation. Complete ablation of IM and HGD occurred in 9 of 10 ablation zones (90%), defined as complete removal of the epithelium with only small foci of "ghost cells" representing nonviable, ablated IM-HGD and demonstrating loss of nuclei and cytoarchitectural derangement. One focal area of viable IM-HGD remained at the margin of one ablation zone (12 J/cm2, 2 applications) because of incomplete overlap.

CONCLUSION

Complete ablation of IM-HGD without ablation of submucosa is possible using the HALO360 system. Ablation depth is dose related and limited to the muscularis mucosae. In one patient, small residual foci of IM-HGD at the edge of the ablation zone were attributable to incomplete overlap, which can be avoided. This study, together with nonesophagectomy IM-HGD trials currently underway, will identify the optimal treatment parameters for IM-HGD patients who would otherwise undergo esophagectomy or photodynamic therapy.

Chromosomal instability in Barrett's esophagus is related to telomere shortening

Barrett's esophagus is a useful model for the study of carcinogenesis, as the metaplastic columnar epithelium that replaces squamous esophageal epithelium is at elevated risk for development of adenocarcinoma. We examined telomere length and chromosomal instability (CIN) in Barrett's esophagus biopsies using fluorescence in situ hybridization. To study CIN, we selected centromere and locus-specific arm probes to chromosomes 17/17p (p53), 11/11q (cyclin D1), and 9/9p (p16 INK4A), loci reported to be involved in early stages of Barrett's esophagus neoplasia. Telomere shortening was observed in Barrett's esophagus epithelium at all histologic grades, whereas CIN was highest in biopsies with dysplastic changes; there was, however, considerable heterogeneity between patients in each variable. Alterations on chromosome 17 were strongly correlated with telomere length (r = 0.55; P < 0.0001) and loss of the 17p arm signal was the most common event. CIN on chromosome 11 was also associated with telomere shortening (r =0.3; P = 0.05), although 11q arm gains were most common. On chromosome 9p, arm losses were the most common finding, but chromosome 9 CIN was not strongly correlated with telomere length. We conclude that CIN is related to telomere shortening in Barrett's esophagus but varies by chromosome. Whether instability is manifested as loss or gain seems to be influenced by the chromosomal loci involved. Because telomere shortening and CIN are early events in Barrett's esophagus neoplastic progression and are highly variable among patients, it will be important to determine whether they identify a subset of patients that is at risk for more rapid neoplastic evolution.

Progress in chemoprevention drug development: the promise of molecular biomarkers for prevention of intraepithelial neoplasia and cancer--a plan to move forward

This article reviews progress in chemopreventive drug development, especially data and concepts that are new since the 2002 AACR report on treatment and prevention of intraepithelial neoplasia. Molecular biomarker expressions involved in mechanisms of carcinogenesis and genetic progression models of intraepithelial neoplasia are discussed and analyzed for how they can inform mechanism-based, molecularly targeted drug development as well as risk stratification, cohort selection, and end-point selection for clinical trials. We outline the concept of augmenting the risk, mechanistic, and disease data from histopathologic intraepithelial neoplasia assessments with molecular biomarker data. Updates of work in 10 clinical target organ sites include new data on molecular progression, significant completed trials, new agents of interest, and promising directions for future clinical studies. This overview concludes with strategies for accelerating chemopreventive drug development, such as integrating the best science into chemopreventive strategies and regulatory policy, providing incentives for industry to accelerate preventive drugs, fostering multisector cooperation in sharing clinical samples and data, and creating public-private partnerships to foster new regulatory policies and public education.

Quality of life in patients with various Barrett's esophagus associated health states

Background

The management of Barrett's esophagus (BE), particularly high grade dysplasia (HGD), is an area of much debate and controversy. Surgical esophagectomy, intensive endoscopic surveillance and mucosal ablative techniques, especially photodynamic therapy (PDT), have been proposed as possible management strategies. The purpose of this study was to determine the health related quality of life associated with Barrett's esophagus and many of the pivotal health states associated with Barrett's HGD management.

Methods

20 patients with Barrett's esophagus were enrolled in a pilot survey study at a large urban hospital. The utility of Barrett's esophagus without dysplasia (current health state) as well as various health states associated with HGD management (hypothetical states as the subject did not have HGD) were measured using a validated health utility instrument (Paper Standard Gamble). These specific health states were chosen for the study because they are considered pivotal in Barrett's HGD decision making. Information regarding Barrett's HGD was presented to the subject in a standardized format that was designed to be easily comprehendible.

Results

The average utility scores (0–1 with 0 = death and 1 = perfect health) for the various Barrett's esophagus associated states were: BE without dysplasia-0.95; Post-esophagectomy for HGD with dysphagia-0.92; Post-PDT for HGD with recurrence uncertainty-0.93; Post-PDT for HGD with recurrence uncertainty and dysphagia-0.91; Intensive endoscopic surveillance for HGD-0.90.

Conclusion

We present the scores for utilities associated with Barrett's esophagus as well as various states associated with the management of HGD. The results of our study may be useful in advising patients and providers regarding expected outcomes of the various HGD management strategies as well as providing utility scores for future cost-effectiveness analyses.

Genetic mechanisms of TP53 loss of heterozygosity in Barrett's esophagus: implications for biomarker validation

BACKGROUND AND AIMS

17p (TP53) loss of heterozygosity (LOH) has been reported to be predictive of progression from Barrett's esophagus to esophageal adenocarcinoma, but the mechanism by which TP53 LOH develops is unknown. It could be (a) DNA deletion, (b) LOH without copy number change, or (c) tetraploidy followed by genetic loss. If an alternative biomarker assay, such as fluorescence in situ hybridization (FISH), provided equivalent results, then translation to the clinic might be accelerated, because LOH genotyping is presently limited to research centers.

METHODS

We evaluated mechanisms of TP53 LOH to determine if FISH and TP53 LOH provided equivalent results on the same flow-sorted samples (n = 43) representing established stages of clonal progression (diploid, diploid with TP53 LOH, aneuploid) in 19 esophagectomy specimens.

RESULTS

LOH developed by all three mechanisms: 32% had DNA deletions, 32% had no copy number change, and 37% had FISH patterns consistent with a tetraploid intermediate followed by genetic loss. Thus, FISH and LOH are not equivalent (P < 0.000001).

CONCLUSIONS

LOH develops by multiple chromosome mechanisms in Barrett's esophagus, all of which can be detected by genotyping. FISH cannot detect LOH without copy number change, and dual-probe FISH is required to detect the complex genetic changes associated with a tetraploid intermediate. Alternative biomarker assay development should be guided by appreciation and evaluation of the biological mechanisms generating the biomarker abnormality to detect potential sources of discordance. FISH will require validation in adequately powered longitudinal studies before implementation as a clinical diagnostic for esophageal adenocarcinoma risk prediction.

Barrett's Metaplasia: defining the problem

Concern over how best to manage individuals with Barrett's esophagus (BE) has grown because of the consistent rise in the incidence of esophageal adenocarcinoma. Since the 1970s, the rate of increase in incidence of esophageal adenocarcinoma has been greater than that for any other cancer in the US population. Patients with BE have increased risk for esophageal cancer, but the rate of progression and potential risk factors in progression remain poorly understood. Much remains to be learned about BE and its association with adenocarcinoma before effective surveillance or management strategies can be defined and implemented. In this article, the relationship between BE and gastroesophageal reflux disease, risk for adenocarcinoma, and prospects for molecular diagnosis are discussed.

Defining a clinically significant adverse impact of diagnosing Barrett's esophagus

BACKGROUND

Diagnosing a potentially life-threatening disease may adversely affect patient quality of life (QOL) independent of biologic effects. It is unknown whether the mere diagnosis of Barrett's esophagus (BE) adversely impacts patients' preferences (health-state utility) sufficiently to impair the cost-effectiveness of endoscopic screening for esophageal adenocarcinoma.

GOAL

To calculate the threshold impact on utility incurred by diagnosing BE that would allow screening to remain cost-effective.

STUDY

A Markov model was developed to examine strategies of no screening, and screening with surveillance of BE. Patients were 50-year-old white men with symptoms of gastroesophageal reflux followed until 80 years of age or death. The primary outcomes were the threshold decrements in utility incurred by diagnosing BE based on willingness to pay (WTP) of dollar 50,000 and dollar 100,000 per quality-adjusted life-year (QALY) gained.

RESULTS

For a WTP of dollar 50,000/QALY, the decrement in utility could be as great as 9%, meaning that screening is cost-effective as long as diagnosing BE does not impair QOL by more than 9%. For a WTP of dollar 100,000, the decrement could be as great as 10.5%.

CONCLUSIONS

The decrement in utility caused by diagnosing BE may be substantial without compromising the cost-effectiveness of endoscopic screening.

Concordant loss of MTAP and p16/CDKN2A expression in gastroesophageal carcinogenesis: evidence of homozygous deletion in esophageal noninvasive precursor lesions and therapeutic implications

The gene that encodes methylthioadenosine phosphorylase (MTAP), an enzyme involved in adenine and methionine salvage pathways, is located on chromosome 9p21 telomeric to the p16INK4A/CDKN2A tumor suppressor gene. Inactivation of the p16INK4A/CDKN2A gene occurs by three different mechanisms: hypermethylation of the gene promoter, intragenic mutation coupled with loss of the second allele, and homozygous deletion. Immunohistochemical labeling for the p16INK4A/CDKN2A gene product parallels gene status but does not elucidate the mechanism of gene inactivation. Since the MTAP gene is often co-deleted with p16INK4A/CDKN2A, concurrent immunolabeling for both proteins can identify cases with homozygous p16INK4A/CDKN2A gene deletion. MTAP loss itself has therapeutic implications since it may confer selective sensitivity to inhibitors of de novo purine biosynthesis, such as L-alanosine. Twelve tissue microarrays were constructed from 92 cases of Barrett-associated adenocarcinomas and precursor lesions and 112 cases of gastric adenocarcinoma and precursor lesions comprising 1161 individual cores. Multiple cores were arrayed from any given case, and when available, included the entire histologic spectrum of intestinal metaplasia-dysplasia-carcinoma. Tissue microarrays were labeled with monoclonal antibodies against MTAP protein (clone 6.9, Salmedix, Inc) and p16 (clone 16P07, Neomarkers). Complete loss of labeling was considered negative, while any labeling (p16: nuclear; MTAP: cytoplasmic and nuclear) was considered positive. Loss of MTAP labeling occurred exclusively in conjunction with loss of p16 labeling, confirming that the previous findings from this group that concurrent loss of MTAP and p16 labeling is a surrogate marker of 9p21 homozygous deletions. Complete loss of MTAP and p16 was seen in 4 of 25 (16%) patients with Barrett's esophagus, 4 of 18 (22%) with low-grade dysplasia, 5 of 39 (13%) with high-grade dysplasia, 17 of 78 (22%) with invasive adenocarcinoma, and 8 of 36 (22%) of metastases. There were 7 cases of esophageal adenocarcinoma with loss of both MTAP and p16 for which precursor lesions were available. In 6 on these 7 cases (85%), the precursor lesion(s) had loss of both MTAP and p16. Lack of MTAP and p16 expression was seen in 11 of 106 (10%) cases of gastric adenocarcinoma. All metaplastic (30 biopsies from 20 cases) and dysplastic (15 biopsies from 13 cases) gastric tissues had both intact MTAP and p16INK4A/CDKN2A gene products. No precursor lesions were available from the gastric cancers that had loss of both MTAP and p16. Two benign gastric hyperplastic polyps also had intact p16 and MTAP. Concurrent MTAP and p16 loss detected by immunohistochemistry can serve as a convenient surrogate for p16INK4A/CDKN2A gene homozygous deletion in archival tissues. Inactivation of p16INK4A/CDKN2A by homozygous deletion appears to be an early event in Barrett carcinogenesis, occurring in noninvasive precursor lesions, including nondysplastic Barrett mucosa, in subsets of cases. In the absence of MTAP, cells depend exclusively on the de novo synthesis pathway for production of adenosine. This loss of MTAP during 9p21 homozygous deletion might be exploited therapeutically using de novo purine synthesis antimetabolites to treat a subset of invasive gastroesophageal adenocarcinomas and esophageal precursor lesions.

Predictive factors of coexisting cancer in Barrett's high-grade dysplasia

BACKGROUND

Identification of high-grade dysplasia (HGD) in Barrett's esophagus has been considered an indication for esophagectomy because of the high risk for coexisting cancer. However, rigorous endoscopic surveillance programs recently have been recommended, reserving esophagectomy for patients whose cancer is identified on biopsy. This approach risks continued surveillance for patients who already have cancer unless reliable markers for the presence of occult cancer are identified. This study aimed to determine the endoscopic, histologic, and demographic features associated with the presence of occult cancer in patients with HGD.

METHODS

Endoscopic, histologic, and demographic findings for 31 patients who underwent esophagectomy for HGD were reviewed. The presence of an ulcer, nodule, stricture, or raised area on preoperative endoscopy was noted. The results of endoscopic biopsies taken before resection every 1 to 2 cm along the Barrett's segment were reviewed. The HGD was categorized as unilevel if the dysplasia was limited to one level of biopsy and as multilevel if more than one level was involved. Patients were divided into two groups according to the presence or absence of cancer in the resected specimens, and these variables were compared.

RESULTS

The prevalence of coexisting cancer in patients with HGD was 45% (14/31). Of the 31 patients in this study, 9 had a visible lesion. Cancer was found in the resected specimens from 7 (78%) of 9 patients with a visible lesion and 7 (32%) of 22 patients without a visible lesion (p = 0.019). Of 22 patients without a visible lesion, 10 had multilevel and 12 had unilevel HGD. The findings showed that 6 (60%) of 10 patients with multilevel HGD and 1 (8.3%) of 12 patients with unilevel HGD had cancer in the resected esophagus (p = 0.009).

CONCLUSION

For patients with HGD, a lesion visible on endoscopy and/or HGD at multiple biopsy levels is associated with an increased risk for coexisting cancer. These patients should be considered for early esophagectomy.

Molecular biology of Barrett's cancer

Oesophageal adenocarcinoma (OA) remains one of the more deadly forms of gastro-intestinal cancer with a mortality rate exceeding 90%. The incidence of OA remains unabated and has a reported fivefold increase since 1970 [Pera M, Cameron AJ, Trastek VF, Carpenter HA & Zinsmeister AR. Increasing incidence of adenocarcinoma of the esophagus and esophagogastric junction. Gastroenterology 1993; 104(2): 510-513]. Gastro-oesophageal reflux disease and its sequelae, Barrett's oesophagus, is one of the principle risk factors in the development of OA, with a 30-fold increased risk in Barrett's patients compared with the general population [Tytgat GNJ. Does endoscopic surveillance in esophageal columnar metaplasia (Barrett's-Esophagus) have any real value. Endoscopy 1995; 27(1): 19-26]. OA is thought to be a microcosm of evolution, developing sequentially along the metaplasia-dysplasia-adenocarcinoma sequence. Progression is attributed to a series of genetic and epigenetic events that ultimately allow for clonal selection of Barrett's cells via subversion of intrinsic control mechanisms regulating cellular proliferation and/or apoptosis. This review will describe the current suppositions of the mechanisms behind the selection and subsequent expansion of Barrett's clones, and focus on some of the principle hallmarks associated with this transition.

Endoscopic mucosal resection for high-grade dysplasia and intramucosal carcinoma in Barrett’s esophagus: An Italian experience

AIM: To evaluate endoscopic mucosal resection (EMR) in patients with high-grade dysplasia (HGD) and/or intramucosal cancer (IMC) in Barrett’s esophagus (BE).

METHODS: Between June 2000 and December 2003, 39 consecutive patients with HGD (35) and/or IMC (4) underwent EMR. BE >30 mm was present in 27 patients. In three patients with short segment BE (25.0%), HGD was detected in a normal appearing BE. Lesions had a mean diameter of 14.8±10.3 mm. Mucosal resection was carried out using the cap method.

RESULTS: The average size of resections was 19.7±9.4×14.6±8.2 mm. Histopathologic assessment post-resection revealed 5 low-grade dysplasia (LGD) (12.8%), 27 HGD (69.2%), 2 IMC (5.1%), and 5 SMC (-12.8%). EMR changed the pre-treatment diagnosis in 10 patients (25.6%). Three patients with SMC underwent surgery. Histology of the surgical specimen revealed 1 T0N0 and 2 T1N0 lesions. The remaining two patients were cancer free at 32.5 and 45.6 mo, respectively. A metachronous lesion was detected after 25 mo in one patient with HGD. Intra-procedural bleeding, controlled at endoscopy, occurred in four patients (10.3%). After a median follow-up of 34.9 mo, all patients remained in remission.

CONCLUSION: In the medium term, EMR is effective and safe to treat HGD and/or IMC within BE and is a valuable staging method. It could become an alternative to surgery.

Photodynamic therapy with porfimer sodium for ablation of high-grade dysplasia in Barrett's esophagus: international, partially blinded, randomized phase III trial

BACKGROUND

Barrett's esophagus (BE) may lead to high-grade dysplasia (HGD) and adenocarcinoma. The objective was to examine the impact of treating patients with BE and with HGD by using porfimer sodium (POR) and photodynamic therapy (PDT) for ablating HGD and reducing the incidence of esophageal adenocarcinoma.

METHODS

The design was a multicenter, partially blinded (pathology), randomized clinical trial conducted in patients with BE who have HGD. There were 30 contributing centers. A total of 485 patients were screened, with 208 in the intent-to-treat population and 202 in the safety population. Patients were randomized on a 2:1 basis to compare PDT with POR plus omeprazole (PORPDT) with omeprazole only (OM). The main outcome measurement was complete HGD ablation occurring at any time during the study period.

RESULTS

There was a significant difference (p < 0.0001) in favor of PORPDT (106/138 [77%]) compared with OM (27/70 [39%]) in complete ablation of HGD at any time during the study period. The occurrence of adenocarcinoma in the PORPDT group (13%) (n=18) was significantly lower (p < 0.006) compared with the OM group (28%) [corrected] (n=20). The safety profile showed 94% of patients in the PORPDT group and 13% of patients in the OM group had treatment-related adverse effects. The limitations of the study were that PDT therapy may have had to be applied more than once and that patients spent more time in treatment. The patients and the physicians were not blinded to the treatment.

CONCLUSIONS

PORPDT in conjunction with omeprazole is an effective therapy for ablating HGD in patients with BE and in reducing the incidence of esophageal adenocarcinoma.

The cost-effectiveness of biomarkers for predicting the development of oesophageal adenocarcinoma

BACKGROUND

The recommended surveillance strategy for oesophageal adenocarcinoma may prevent as few as 50% of cancer deaths. Tissue biomarkers have been proposed to identify high-risk patients.

AIM

To determine performance characteristics of an ideal biomarker, or panel of biomarkers, that would make its use more cost-effective than the current surveillance strategy.

METHODS

We created a Markov model using data from published literature, and performed a cost-utility analysis. The population consisted of 50-year-old Caucasian men with gastro-oesophageal reflux, who were monitored until age 80. We examined strategies of observation only, current practice (dysplasia-guided surveillance), surveillance every 3 months for patients with a positive biomarker (biomarker-guided surveillance), and oesophagectomy immediately for a positive biomarker (biomarker-guided oesophagectomy). The primary outcome was the threshold cost and performance characteristics needed for a biomarker to be more cost-effective than current practice.

RESULTS

Regardless of the cost, the biomarker needs to be at least 95% specific for biomarker-guided oesophagectomy to be cost-effective. For biomarker-guided surveillance to be cost-effective, a $100 biomarker could be 80% sensitive and specific.

CONCLUSIONS

Biomarkers predicting the development of oesophageal adenocarcinoma would need to be fairly accurate and inexpensive to be cost-effective. These results should guide the development of biomarkers for oesophageal adenocarcinoma.

CDC2/CDK1 expression in esophageal adenocarcinoma and precursor lesions serves as a diagnostic and cancer progression marker and potential novel drug target

Esophageal adenocarcinoma arises through well-defined precursor lesions (Barrett esophagus), although only a subset of these lesions advances to invasive adenocarcinoma. The lack of markers predicting progression in Barrett esophagus, typical presentation at advanced stage, and limitations of conventional chemotherapy result in >90% mortality for Barrett-associated adenocarcinomas. To identify potential prognostic markers and therapeutic targets, we compared gene expression profiles from Barrett-associated esophageal adenocarcinoma cell lines (BIC1, SEG1, KYAE, OE33) and normal esophageal epithelial scrapings utilizing the Affymetrix U133_A gene expression platform. We identified 560 transcripts with >3-fold up-regulation in the adenocarcinoma cell lines compared with normal epithelium. Utilizing tissue microarrays composed of normal esophageal squamous mucosa (n = 20), Barrett esophagus (n = 10), low-grade dysplasia (n = 14), high-grade dysplasia (n = 27), adenocarcinoma (n = 59), and node metastases (n = 27), we confirmed differential up-regulation of three proteins (Cdc2/Cdk1, Cdc5, and Igfbp3) in adenocarcinomas and Barrett lesions. Protein expression mirrored histologic progression; thus, 87% of low-grade dysplasias had at least focal surface Cdc2/Cdk1 and 20% had >5% surface staining; 96% of high-grade dysplasias expressed abundant surface Cdc2/Cdk1, while invasive adenocarcinoma and metastases demonstrated ubiquitous expression. Esophageal adenocarcinoma cell lines treated with the novel CDC2/CDK1 transcriptional inhibitor, tetra-O-methyl nordihydroguaiaretic acid (EM-1421, formerly named M4N) demonstrated a dose-dependent reduction in cell proliferation, paralleling down-regulation of CDC2/CDK1 transcript and protein levels. These findings suggest a role for CDC2/CDK1 in esophageal adenocarcinogenesis, both as a potential histopathologic marker of dysplasia and a putative treatment target.

Dysplasia in Barrett's esophagus: limitations of current management strategies

Dysplasia is a very imperfect biomarker for malignancy in Barrett's esophagus. Invasive cancer has been found in 30-40% of esophagi resected because preoperative endoscopic examinations had shown high-grade dysplasia. Reports on the natural history of this disorder are sometimes contradictory, but suggest that 10-30% of patients with high-grade dysplasia in Barrett's esophagus will develop a demonstrable malignancy within 5 yr of the initial diagnosis. Proposed management strategies for high-grade dysplasia include esophagectomy, endoscopic ablative therapies, endoscopic mucosal resection (EMR), and intensive endoscopic surveillance. Endoscopic ablative therapies and EMR may not be effective if neoplastic cells have invaded the submucosa or disseminated through mucosal lymphatic channels, and a number of studies suggest that the endoscopic therapies usually leave metaplastic or neoplastic epithelium with malignant potential behind. Limited data suggest that intensive endoscopic surveillance might be a reasonable approach for elderly or infirm patients, but some patients managed in this fashion have developed incurable esophageal cancers. The fundamental question of what is the appropriate length of follow-up for studies on dysplasia treatments has not been resolved. Although 5 yr might be considered the absolute minimum duration for a meaningful follow-up on dysplasia therapy, the follow-up duration in most studies is substantially less than 5 yr. Specific recommendations for management based on these considerations are proposed at the end of this report.

High-grade dysplasia in Barrett's oesophagus: natural history and review of clinical practice

BACKGROUND

Management of high-grade dysplasia in Barrett's oesophagus is controversial: surgery carries an appreciable morbidity/mortality, high-grade dysplasia may not progress to cancer and endoscopic ablation is an emerging option.

AIM

To review Barrett's oesophagus-related high-grade dysplasia management and outcome over a 10-year period.

METHODS

This was a retrospective case note review of 36 patients identified from a pathology database.

RESULTS

There were 31 men of mean age 67 years. Endoscopic surveillance identified nine. Median follow-up was 21 months. Seven patients had no further intervention because of age/comorbidity. The other 29 had repeat endoscopic biopsies, nine showing cancer (six oesophagectomized). Of the 20 remaining patients with persisting high-grade dysplasia, eight had surgery (histology showed cancer in six), seven continued endoscopic surveillance (high-grade dysplasia regressed in four) and five had 'curative' argon ablation. An intensive biopsy protocol was not followed in 55% of endoscopies. Prevalent cancers occurred in 44% with an annual incidence of 5% over 5 years. All cause mortality was 39% (14 of 36, eight of 14 from cancer).

CONCLUSIONS

Management of high-grade dysplasia was not uniform. Unsuspected cancer was common in high-grade dysplasia patients undergoing surgery but 13% regressed under surveillance. High-grade dysplasia patients have a high mortality but 43% did not die from cancer.

Present status of photodynamic therapy for high-grade dysplasia in Barrett's esophagus

GOALS

Review recent developments in Barrett's dysplasia including regulatory approval of porfimer sodium photodynamic therapy.

BACKGROUND

Barrett's esophagus is thought to be the result of long-standing gastroesophageal reflux disease and is known to be the most important risk factor for the development of esophageal adenocarcinoma. The natural history of Barrett's esophagus is not well known, but the annual incidence of invasive adenocarcinoma is estimated to be 0.5% (reported range, 0.2%-2.0%). This represents an increased risk for esophageal cancer of 30 to 60 times higher than normal subjects. As for colorectal cancer, malignant degeneration is Barrett's esophagus is thought to occur through a continuum of histologic stages: metaplasia, dysplasia and neoplasia. Barrett's high-grade dysplasia (formerly referred to as carcinoma in situ) is the histologic stage of disease that immediately precedes the development of invasive carcinoma.

CONCLUSIONS

Previously, Barrett's high-grade dysplasia patients were routinely referred for esophageal resection surgery based upon the assumption of inevitable progression to cancer, the high rate of undiagnosed synchronous cancers, and few treatment alternatives. Important developments in Barrett's high-grade dysplasia include recent publications regarding the natural history of Barrett's high-grade dysplasia and the regulatory approval for endoscopic ablation therapy using porfimer sodium photodynamic therapy (Photofrin PDT).

Is There a Way for Pathologists to Decrease Interobserver Variability in the Diagnosis of Dysplasia?

Many obstacles interfere with our efforts to screen patients with Barrett esophagus. Probably the largest is choosing the appropriate patient group for screening. Beyond this problem, sampling error on the part of endoscopists is probably more serious a problem than observer variation among pathologists reviewing patient samples. Pathologists agree well on lesions that merit close follow-up or other intervention (high-grade dysplasia and invasive carcinoma), although interobserver agreement between pathologists interpreting lesser lesions is not good. This lack of agreement is not likely to improve substantially, and many adjunct markers are being sought in an attempt to identify patients with lesions of lower grades that are most likely to progress, allowing doctors to identify patients who would benefit from upgraded surveillance.

Patient preferences for the management of high-grade dysplasia in Barrett's esophagus

Surgical esophagectomy, intensive endoscopic surveillance, and mucosal ablative techniques, particularly photodynamic therapy (PDT), have been proposed as possible management strategies for Barrett's high-grade dysplasia (HGD). Each option has advantages and disadvantages, and no firm consensus exists for the preferred strategy at this time. The purpose of this pilot study was to gain insight into patient preferences in Barrett's HGD management. Twenty patients with Barrett's esophagus were enrolled in a questionnaire study. The three possible management options for Barrett's HGD including each option's potential benefits and harms were presented to the subject in a formalized presentation that was designed to be easily comprehendible by patients. The subjects rated each strategy using a health-related quality of life instrument and chose one of the management strategies assuming they were found to have HGD. The average feeling thermometer rating scale values for the management strategies were as follows: endoscopic surveillance, 79; esophagectomy, 46; and PDT, 60. When asked to choose a strategy, 14 (70%) chose endoscopic surveillance, 3 (15%) chose esophagectomy, and 3 (15%) chose PDT. These findings were statistically significant (P = 0.0024). The patients who chose endoscopic surveillance felt "comfortable" with endoscopy, while the most common concern about esophagectomy, and PDT was the risk of death and the unknown risk of recurrence, respectively. In summary, when patients with Barrett's esophagus were presented with three options to manage HGD, the majority chose endoscopic surveillance. Familiarity with endoscopic surveillance was the predominant reason for the choice.

Surgical aspects of the patient with high-grade dysplasia

The incidence of esophageal cancer has increased dramatically in the Western population in the last 2 decades. In 1975, about three fourths of the esophageal neoplasms were squamous cell carcinomas and the remainder were adenocarcinomas. During the last 2 to 3 decades, this pattern has changed dramatically and the incidence of squamous cell carcinomas has declined while the incidence of adenocarcinomas has increased. The reason for this dramatic increase is not clear, but gastro esophageal reflux disease, obesity and Barrett's esophagus have been identified as risk factors. High grade dysplasia in Barrett's esophagus is a premalignant condition which can progress to invasive adenocarcinoma. In this article, we discuss the natural history of high grade dysplasia (HGD), difficulties in the diagnosis, the incidence of adenocarcinoma in resected specimens and the surgical aspects in the treatment of HGD, including minimally invasive esophagectomy.

Cost-effectiveness of photodynamic therapy for high-grade dysplasia in Barrett's esophagus

BACKGROUND

Photodynamic therapy appears to be effective in ablating high-grade dysplasia in Barrett's esophagus. Our aim was to identify the most effective and cost-effective strategy for managing high-grade dysplasia in Barrett's esophagus without associated endoscopically visible abnormalities.

METHODS

By using decision analysis, the lifetime costs and benefits of 4 strategies for which long-term data exist were estimated by us: esophagectomy, endoscopic surveillance, photodynamic therapy, followed by esophagectomy for residual high-grade dysplasia; and photodynamic therapy followed by endoscopic surveillance for residual high-grade dysplasia. It was assumed by us that there was a 30% prevalence of cancer in high-grade dysplasia patients and a 77% efficacy of photodynamic therapy for high-grade dysplasia and early cancer.

RESULTS

Esophagectomy cost 24,045 dollars, with life expectancy of 11.82 quality-adjusted life years. In comparison, photodynamic therapy followed by surveillance for residual high-grade dysplasia was the most effective strategy, with a quality-adjusted life expectancy of 12.31 quality-adjusted life years, but it also incurred the greatest lifetime cost (47,310 dollars) for an incremental cost-effectiveness of 47,410 dollars/quality-adjusted life years. The results were sensitive to post-surgical quality of life and survival, and to cancer prevalence if photodynamic therapy efficacy for cancer was less than 50%.

CONCLUSIONS

Photodynamic therapy followed by endoscopic surveillance for residual high-grade dysplasia appears to be cost effective compared with esophagectomy for patients diagnosed with high-grade dysplasia in Barrett's esophagus. Clinical trials directly comparing these strategies are warranted.

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

OBJECTIVES

To examine DNA content abnormalities in patients with Barrett's esophagus (BE) who progress to esophageal adenocarcinoma, using image cytometric DNA analysis (ICDA) of formalin-fixed tissues.

METHODS

Studies were performed on archived biopsies of BE patients' undergoing endoscopic surveillance before developing adenocarcinoma. A comparison group consisted of BE patients' free of cancer during a follow-up period of over 9 yr. Tissue sections were analyzed for the degree of dysplasia and for DNA content abnormalities, using image cytometry. Additional patients were also analyzed in a cross-sectional study of 56 BE cases with and without dysplasia, including 12 cases of adenocarcinoma.

RESULTS

Five patients developed adenocarcinoma during follow-up and earlier biopsies obtained before cancer diagnosis showed specialized intestinal metaplasia (SIM) followed by low-grade dysplasia (LGD) in one, SIM followed by high-grade dysplasia (HGD) in one, LGD in two, and HGD in one case. All five showed some DNA abnormality at baseline or in interval biopsies. In the comparison group, five of seven patients showed normal diploid DNA at baseline and on follow-up biopsies. One patient initially had diploid DNA, but developed aneuploidy 11 yr later. Another case initially had aneuploidy, but was diploid on follow-up. Overall, DNA abnormalities were found in 13% of cases with SIM without dysplasia, 60% with LGD, 73% with HGD, and 100% with adenocarcinoma.

CONCLUSIONS

(i) Image cytometric DNA analysis is a useful method to examine DNA abnormalities in formalin-fixed tissues and may be more sensitive in predicting progression to adenocarcinoma than HGD. (ii) Histological dysplasia of any grade and DNA abnormalities, help identify BE patients at high risk for adenocarcinoma.

Risk stratification of Barrett's esophagus: updated prospective multivariate analysis

OBJECTIVES

Prospective evaluation of Barrett's esophagus (BE) in order to determine what demographic, endoscopic, and histologic features are predictive of the prevalence and incidence of Barrett's high-grade dysplasia (HGD) and adenocarcinoma (Ca).

METHODS

Newly diagnosed BE patients were entered into and followed in a standardized surveillance protocol. The following features were examined using either forward, stepwise multiple regression analysis, or Cox proportional hazards to determine their ability to predict the presence of HGD or Ca at index BE diagnosis as well as their ability to predict progression of BE during follow-up: age, race, gender, length of BE in cm, size of a hiatal hernia, severity of dysplasia at index diagnosis as well as during surveillance, gastric Helicobacter pylori infection status, and type of medical acid-reflux treatment.

RESULTS

A total of 550 patients were diagnosed with BE over the study period. Stepwise multiple regression analysis showed three factors significantly associated with index diagnosis of HGD or Ca: hiatal hernia (larger size), Barrett's length (longer length), and absence of H. pylori infection. Three hundred and twenty-four BE entered the surveillance protocol. Cox proportional hazards models revealed a significant and independent association for five factors predictive of the time to progression of BE: presence of dysplasia at index diagnosis (p < 0.001), severity of dysplasia during surveillance (p < 0.001), length of Barrett's epithelium (p= 0.012), size of hiatal hernia (p= 0.006), and gastric H. pylori infection status (p= 0.023).

CONCLUSIONS

Endoscopic and histologic features of BE at initial diagnosis are predictive of index HGD and cancer as well as with risk of BE progression.

A critical review of the diagnosis and management of Barrett's esophagus: the AGA Chicago Workshop

BACKGROUND & AIMS

The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues.

METHODS

A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion.

RESULTS

There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia.

CONCLUSIONS

Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Barrett's esophagus: current and future role of endosonography and optical coherence tomography

This paper reviews the role of endosonography and optical coherence tomography (OCT) for imaging of Barrett's esophagus (BE). The routine use of endoscopic ultrasound (EUS) to screen patients with BE is neither justified nor cost effective. EUS does appear to have a role in patients who have BE and high-grade dysplasia or intramucosal carcinoma, in whom a non-operative therapy is being contemplated. For patients with a diagnosis of esophageal cancer with or without BE, EUS is superior to computed tomography or magnetic resonance imaging for assessing esophageal wall penetration and for detecting regional lymph node involvement. In its current state, OCT is not yet ready for application in clinical practice. However, given its superior resolution compared with other modalities such as EUS, OCT has great potential as a powerful adjunct to standard endoscopy in surveillance of BE and may enhance the ability of endoscopists to detect high-grade dysplasia at an early stage. With further technical refinement, this technique may become a mainstay in the surveillance of BE and other premalignant conditions of the gastrointestinal tract.

Photodynamic therapy with green light and m-tetrahydroxyphenyl chlorin for intramucosal adenocarcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND

The eradication of early stage neoplastic lesions in Barrett's esophagus is imperative to prevent invasive adenocarcinoma. Early stage lesions have an extremely low risk of lymph node metastasis, thereby, making local treatment feasible. Photodynamic therapy destroys malignant cells by a photochemical effect. The aims of this study were to evaluate the efficacy and tolerance of photodynamic therapy with green light and a new photosensitizer, temoporfin or m-tetrahydroxyphenyl chlorin in patients with Barrett's esophagus and early stage neoplastic lesions.

METHODS

Four days after injection of m-tetrahydroxyphenyl chlorin, lesions were illuminated at a wavelength of 514 nm through non-circumferential windowed diffusers. Follow-up endoscopy with biopsies was performed at regular intervals.

RESULTS

Fourteen lesions (7 high-grade dysplasia, 7 intramucosal adenocarcinoma) in 12 patients were treated. For all lesions, efficacy was 100% and squamous re-epithelialization was complete. Side effects were of moderate severity (one stricture). Mean follow-up was 34 (15) months (range 12-68 months).

CONCLUSIONS

Green light photodynamic therapy with m-tetrahydroxyphenyl chlorin can eradicate early stage neoplastic lesions in Barrett's esophagus and may be proposed as an alternative first-line therapy or a second-line therapy after failure of other endoscopic treatments. The efficacy and patient tolerance of the procedure justify further studies of the method in larger groups of patients.

Barrett's esophagus: management of high-grade dysplasia and cancer

Esophagectomy remains the treatment of choice for the appropriate patient with Barrett's adenocarcinoma invading beyond the mucosa, without evidence of distant metastasis or invasion of adjacent organs. On the other hand, therapeutic management of patients with Barrett's high-grade dysplasia (HGD) or mucosal adenocarcinoma should be individualized, taking into account the patient's preferences, willingness to return for frequent endoscopic biopsies, and medical fitness to undergo esophagectomy. Surgery has to be considered the best treatment for HGD or superficial carcinoma, unless contraindicated by severe comorbidities, because it has proven to be the only treatment that is successful in curing the condition and preventing recurrent HGD or the development of invasive cancer. Nonsurgical treatment by photodynamic therapy or endoscopic mucosal resection may be a less invasive and organ-sparing option for elderly, poor-risk patients but it is still to be considered an investigational therapy that should only be conducted under a clinical trial protocol. Finally, intensive endoscopic biopsy surveillance of patients with HGD is another investigational option that may allow prompt treatment of cancer if it develops. However, few data document the safety of this observational approach.

Biomarkers of esophageal adenocarcinoma and Barrett's esophagus

The rising incidence and poor prognosis of esophageal adenocarcinoma in the Western world have intensified research efforts into earlier methods of detection of this disease and its relationship to Barrett's esophagus. The progression of Barrett's esophagus to adenocarcinoma has been the focus of particular scrutiny, and a number of potential tissue and serum-based disease biomarkers have emerged. The epidemiology and pathogenesis of esophageal adenocarcinoma are outlined. Tissue biomarkers allowing risk stratification of Barrett's are reviewed as well as strategies currently being used to discover novel biomarkers that will facilitate the early detection of esophageal adenocarcinoma. Finally, the uses of biomarkers as predictive tests for targeted treatments and as surrogate endpoints in chemoprevention trials are considered.

Autofluorescence endoscopy for detection of high-grade dysplasia in short-segment Barrett's esophagus

BACKGROUND

The occurrence of precancerous lesions, such as high-grade dysplasia, in patients with short-segment Barrett's esophagus is controversial. This study assessed the efficacy of autofluorescence endoscopy for detection of high-grade dysplasia in short-segment Barrett's esophagus.

METHODS

A total of 34 patients (28 men, 6 women; age range 40-77 years) with histopathologically proven short-segment Barrett's esophagus were studied. Autofluorescence endoscopy was performed by using monochromatized blue light (425-455 nm) filtered from a conventional xenon light source. A total of 136 and 109 biopsy specimens were taken from Barrett's mucosa under control, respectively, white light endoscopy and autofluorescence endoscopy.

RESULTS

High-grade dysplasia was found in 9 (8.3%) autofluorescence-guided biopsy specimens, which was significantly greater than the number of white light endoscopy-guided biopsy specimens with this finding (one positive biopsy specimen, 0.7% of total biopsy specimens obtained). Autofluorescence endoscopy detected high-grade dysplasia in 7 patients, 6 more than were identified with white light endoscopy. In the one patient with high-grade dysplasia detected by white light endoscopy-guided biopsy specimens, autofluorescence-guided biopsy specimens revealed only low-grade dysplasia.

CONCLUSION

Autofluorescence endoscopy in patients with short-segment Barrett's esophagus increases the detection rate of high-grade dysplasia.

Clinical Manifestations and Esophageal Complications of GERD

This report focuses on the manifestations of gastroesophageal reflux disease (GERD) that are caused directly by contact between refluxed gastric juice and the esophageal mucosa. These manifestations include heartburn, peptic esophageal erosion and ulceration, peptic esophageal stricture, and Barrett esophagus. Peptic esophageal erosions and ulcerations are excavated defects in the esophageal mucosa that result when epithelial cells succumb to the caustic effects of refluxed acid and pepsin. Uncommonly, esophageal ulcers are complicated by hemorrhage, perforation, and penetration into the airway. Esophageal ulcers can stimulate fibrous tissue production and collagen deposition that result in stricture formation, and the ulcers can heal through a metaplastic process in which an intestinal-type epithelium replaces the damaged squamous cells (Barrett esophagus). The management of these conditions is discussed below.

Management of Barrett's oesophagus in 2001 in Ireland

BACKGROUND

Endoscopic surveillance of patients with Barrett's oesophagus is recommended to detect early carcinoma. The practice patterns of endoscopists since the publication of more recent management guidelines remain unknown.

METHODS

All endoscopists (n=68) in the Irish Medical Directory and their trainees were sent a postal questionnaire on Barrett's surveillance.

RESULTS

Fifty-five per cent (30/54) perform surveillance on all patients with Barrett's oesophagus and 38% on selected patients. In patients with no dysplasia, repeat endoscopy was more commonly practiced annually (28/54) than every two to three years (23/54). Surgeons were more likely to perform surveillance annually than gastroenterologists (75% vs 40%). Only 26% of endoscopists took four-quadrant biopsies every 2 cm. Intervention was recommended by a majority (28/54) of endoscopists in a patient with high grade dysplasia. A majority of respondents (47/54) would have surveillance if they were found to have Barrett's oesophagus.

CONCLUSION

Most endoscopists in Ireland do not adhere to recent guidelines in their management of Barrett's oesophagus. Surgical endoscopists perform surveillance more frequently than their medical colleagues.

Role of cytology in the diagnosis of Barrett's esophagus and associated neoplasia

We studied 327 consecutive paired esophageal biopsies and brushing specimens obtained during the same endoscopic session to evaluate the role of cytology for the diagnosis of Barrett's esophagus (BE) and/or surveillance for associated dysplasia. A diagnosis of BE was based on the cytologic presence of goblet cells. Cases were reviewed and categorized into: 1) benign esophageal lesions (125 cases), with 48 cases of Candida (32 cases diagnosed by both techniques and 16 diagnosed only by cytology), 3 cases of herpes simplex with only 1 case diagnosed by cytology, and 74 cases of inflammation and/or repair; 2) benign BE (141 cases), with 74 cases (52%) diagnosed by both techniques, 11 cases by cytology only (8%), and 56 cases (40%) by histology only; 3) low-grade dysplasia (LGD, 30 cases), with 5 cases (17%) diagnosed with both specimens, one case (3%) by cytology only, and 24 cases (80%) by histology only; 4) high-grade dysplasia (HGD, 10 cases), with 8 cases (80%) diagnosed with both specimens, 1 case (10%) by cytology, and 1 case (10%) by histology; and 5) carcinomas (23 cases), with 20 cases (87%) diagnosed with both specimens, 2 cases (9%) by cytology only, and 1 case (4%) by histology only. Our results support the high degree of diagnostic accuracy of cytology for the diagnosis of Barrett's-associated HGD and/or carcinoma, and moderate sensitivity for BE.

Reflux, Barrett's oesophagus and adenocarcinoma: burning questions

The incidence of oesophageal adenocarcinoma is increasing rapidly in Western populations. Gastro-oesophageal reflux disease is a strong risk factor for both this tumour and the pre-cancerous lesion Barrett's oesophagus, but the underlying disease mechanisms remain unclear. Developing a better understanding of the aetiology and pathogenesis of Barrett's oesophagus, including the induction of DNA damage and genetic alterations, might provide opportunities for improved management of individuals with this disease. This could include a better rationale for screening and surveillance programmes, as well as targeted intervention strategies.

Photodynamic therapy for Barrett's esophagus with dysplasia and/or early stage carcinoma: long-term results

BACKGROUND

Photodynamic therapy has been shown to eliminate Barrett's dysplasia. This report presents long-term follow-up data after photodynamic therapy of Barrett's esophagus with high-grade dysplasia, low-grade dysplasia, or early stage carcinoma.

METHODS

Porfimer-photodynamic therapy was performed in 103 patients. The Nd:YAG laser was used to photoablate small areas of residual or untreated Barrett's mucosa. Acid suppression was maintained in all patients (omeprazole, 20 mg twice a day).

RESULTS

Mean follow-up was 50.65 (SD 20.57) months (range 2-122 months). For the 82 patients not lost to follow-up, mean follow-up was 58.5 (12.89) months (range 41-132 months). After photodynamic therapy, the length of Barrett's mucosa decreased by a mean of 6.92 cm (range 1-22 cm). Of the 65 patients with high-grade dysplasia, 60 (94%) had elimination of high-grade dysplasia. Three (4.6%) patients developed subsquamous adenocarcinoma. Subsquamous, nondysplastic, metaplastic epithelium was found in 4 patients (4.9%). Strictures occurred in 18% with one session of photodynamic therapy, and 50% with two treatments, 30% overall. For the 103 patients, intention-to-treat success rates were 92.9%, 77.5%, and 44.4% for, respectively, low-grade dysplasia, high-grade dysplasia, and early stage carcinoma groups.

CONCLUSION

Porfimer-photodynamic therapy with supplemental Nd:YAG photoablation and continuous treatment with omeprazole reduces the length of Barrett's mucosa, eliminates high-grade dysplasia, and, by comparison with historical data, may reduce the expected frequency of carcinoma.

Follow-up for high-grade dysplasia in Barrett's esophagus

This article will focus on the value of endoscopic follow-up for patients with high-grade dysplasia (HGD). Because the diagnosis of HGD in Barrett's esophagus is not a simple straightforward task, the article first will discuss the controversies regarding the histological diagnosis, followed by a discussion of the importance of endoscopic imaging for making the clinical diagnosis of HGD, and a systematic review of the literature relating to the presence of synchronous cancers in patients with HGD and the occurrence of cancer during endoscopic follow-up in these patients (metachronous cancers). Furthermore, the article will also discuss endoscopic techniques currently available for surveillance of these patients and make recommendations regarding surveillance intervals and the optimal biopsy protocol.

Use of lasers in Barrett's esophagus

Lasers are used in the management of Barrett's esophagus for specific tasks. First is for the ablation of non-dysplastic and dysplastic Barrett's as part of an aggressive, minimally invasive, yet unproven preventive interventional strategy for both low-risk and high-risk of progression subgroups. Secondly is for potentially curative treatment of early mucosal cancers (Tis and T1mN0M0). Finally, lasers are used for palliation of dysphagia for advanced tumors. The first two laser uses should be considered experimental and undertaken in the setting of an institutionally approved research protocol. Paramount to the success of ablation of dysplastic and early cancerous Barrett's is careful selection of patients by meticulous video endoscopic inspection of the mucosa, use of high frequency and dedicated endosonography (to uncover unsuspected tumors that penetrate the submucosa or involve lymph nodes that cannot be targeted by laser treatment), and experienced GI pathologists. Lasers can also play an important adjuvant role in the management of dysphagia for advanced cancers: however, the specific patients' characteristics for this group of patients is currently not well-defined in this era of easily placed expandable metallic stents.

Medical decision analysis of chemoprevention against esophageal adenocarcinoma

BACKGROUND & AIMS

Chemoprevention of esophageal adenocarcinoma using nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the risk of cancer in patients with Barrett's esophagus. The aim of the study was to assess the cost-effectiveness of this strategy.

METHODS

The incremental cost-effectiveness ratio (ICER) of chemoprevention (compared with endoscopic surveillance or with no surveillance) was analyzed with a computer model of a Markov process.

RESULTS

Under baseline conditions for all patients with Barrett's esophagus (neoplastic and nonneoplastic), the ICER of chemoprevention ranges between $12,700 and $18,500 US dollars per life-year saved. However, these cost values are sensitive to variations in the costs of chemoprevention, incidence of cancer in patients with Barrett's esophagus, and efficacy of NSAIDs in reducing the incidence of cancer, which can shift the ICER into a cost range that is prohibitively expensive. Conversely, in those patients with Barrett's esophagus and high-grade dysplasia, the ICER ranges between $3900 and $5000 US dollars. Chemoprevention remains a cost-effective option even under rather unfavorable conditions, such as higher cost and lower efficacy of chemoprevention and lower incidence of cancer.

CONCLUSIONS

This model suggests that a high incidence of esophageal adenocarcinoma in high-grade dysplasia renders chemoprevention cost-effective even in the presence of less-favorable conditions. However, chemoprevention may not be a cost-effective measure in the general population of all patients with Barrett's esophagus, depending on unknown factors such as cost and efficacy of chemoprevention as well as true incidence of cancer.

The natural history of dysplasia and cancer in esophagitis and Barrett esophagus

The natural history of metaplasia and dysplasia in Barrett esophagus is not well defined. Publication bias, the selective reporting of studies that have positive or extreme results, has exaggerated the risk of esophageal adenocarcinoma in this condition. Recent data suggest that patients with Barrett esophagus develop these tumors at the rate of 0.5% per year, a cancer incidence considerably lower than was appreciated just a few years ago. Indirect evidence suggests that aggressive treatment of gastroesophageal reflux might decrease the risk of carcinogenesis, but no therapy yet has been proved to decrease the incidence of cancer in Barrett esophagus. Dysplasia in the metaplastic epithelium clearly is a worrisome finding, but the progression from dysplasia to cancer may take years and may not be inevitable.