Predictors of progression to cancer in Barrett's esophagus: baseline histology and flow cytometry identify low- and high-risk patient subsets

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Preemptive surgery for premalignant foregut lesions

INTRODUCTION

Preemptive surgery is the prophylactic removal of an organ at high risk for malignant transformation or the resection of a precancerous or "early" malignant neoplasm in an individual with a hereditary predisposition to cancer. Recent advances in molecular diagnostic techniques have improved our understanding of the biologic behavior of these conditions. Predictive testing is an emerging field that attempts to assess the potential risk of cancer development in predisposed individuals. Despite substantial improvement in these forms of testing, all results are imperfect. This information often becomes an important tool that is used by healthcare providers to evaluate the risk-benefit ratio of various risk modifying strategies (i.e., intensive surveillance or preemptive surgery).

METHODS

A systematic literature review was performed using Medline and the bibliographies of all referenced publications to identify articles relating to preemptive surgery for premalignant foregut lesions.

RESULTS AND DISCUSSION

In this review, we outline the controversies surrounding predictive risk assessment, surveillance strategies, and preemptive surgery in the management of high-grade dysplasia (HGD) in Barrett's esophagus (BE), hereditary diffuse gastric cancer (HDGC), bile duct cysts, primary sclerosing cholangitis (PSC), and pancreatic cystic neoplasms. Resection of BE is supported by the progressive nature of the disease, the risk of occult carcinoma, and the lethality of esophageal cancer. Prophylactic total gastrectomy for HDGC appears reasonable in the absence of accurate screening tests but must be balanced by the impact of surgical complications and altered quality of life. Surgical resection of biliary cysts theoretically eliminates the exposed epithelium to decrease the lifetime risk of cholangiocarcinoma. Liver transplantation for PSC remains controversial given the scarcity of donor organs and inability to accurately identify high-risk individuals. Given the uncertain natural history of pancreatic cystic neoplasms, the merits of selective versus obligatory resection will continue to be debated.

CONCLUSIONS

Preemptive operations require optimal judgment and surgical precision to maximize function and enhance survival. Ultimately, balancing the risk of surgical intervention with less invasive interventions or observation must be individualized on a case-by-case basis.

DNA promoter hypermethylation of p16 and APC predicts neoplastic progression in Barrett's esophagus

OBJECTIVES

Prediction of progression to cancer in patients with Barrett's esophagus (BE) is difficult using current techniques. We determined whether DNA promoter hypermethylation of genes frequently methylated in esophageal adenocarcinoma (p16 and APC) could be used as predictors of progression in BE.

METHODS

We first performed a cross-sectional study to evaluate the prevalence of gene hypermethylation in biopsies from patients with normal esophagus (n=17), BE (n=102), and adenocarcinoma (n=42). We then performed a nested case-control study comparing gene hypermethylation in BE patients who progressed from baseline pathology to high-grade dysplasia or cancer (n=7) vs. patients who did not progress (n=50).

RESULTS

None of the patients with normal esophagus had p16 or APC hypermethylation. Hypermethylation was prevalent in BE without dysplasia or low-grade dysplasia (p16=31% and APC=50%; P<0.01) and high-grade dysplasia or adenocarcinoma (p16=54% and APC=68%; P<0.001) compared with normal esophagus (not detected). Patients who progressed from baseline pathology to high-grade dysplasia or cancer had higher prevalence of hypermethylation in their initial esophagus biopsies compared with those who did not progress for both p16 (100 vs. 33%; P=0.008) and APC (86 vs. 40%; P=0.02). Hypermethylation of both p16 and APC was a strong predictor of subsequent progression to high-grade dysplasia or cancer during a mean follow-up time of 4.1 years (odds ratio (95% confidence interval)=14.97 (1.73,inf), P=0.01). Among patients who were negative for both p16 and APC hypermethylation, none progressed from baseline pathology to high-grade dysplasia or cancer.

CONCLUSIONS

Hypermethylation of both p16 and APC strongly predicts progression to high-grade dysplasia or cancer in patients with BE. Absence of p16 and APC hypermethylation is associated with a benign course.

HER-2 overexpression/amplification in Barrett's oesophagus predicts early transition from dysplasia to adenocarcinoma: a clinico-pathologic study

Barrett's oesophagus (BO) is the primary precursor lesion for oesophageal adenocarcinoma (ADC). The natural history of metaplasia-dysplasia-carcinoma sequence remains largely unknown. HER2/neu oncogene results overexpressed/amplified in preneoplastic lesions and in ADC of the oesophagus and it has been associated with poor prognosis. Our aim was to evaluate the role of HER2 overexpression/amplification in predicting the conversion from precursor lesions to ADC. We retrospectively evaluated by univariate analysis of single variables clinical records and histological specimens of 21 patients with a confirmed diagnosis of BO and/or oesophageal dysplasia. Clinical variables included age, gender, alcohol and smoking intake, presence of symptoms (pyrosis, disphagia) and endoscopic features (length). HER2 status was studied by immunohistochemistry and fluorescence in situ hybridization (FISH) on paraffin-embedded tissue. The end-points were the occurrence of progression and the time-to-progression (TTP) from the initial histologic lesion to the worst pathological pattern. Median age at diagnosis was 63 years (range 37-84). BO median length was 4.5 cm. Progression occurred in 11 of 21 patients and median TTP was 24 months. HER2 was overexpressed/amplified in 8 of 21 (38%) patients. HER2 overexpression/ amplification and the presence of dysplasia were statistically associated with progression (P= 0.038). This study provides evidence for a possible role of HER2 in the transition from dysplasia to ADC of the oesophagus. This fact could help in identifying patients at high risk of malignant transformation.

Barrett esophagus: histology and pathology for the clinician

The incidence of adenocarcinoma of the esophagus and gastroesophageal junction has increased dramatically over the past 30 years. The major precursor to this type of adenocarcinoma is Barrett esophagus, which is defined as the conversion of normal squamous epithelium into metaplastic columnar epithelium. Abundant evidence suggests that adenocarcinoma in the setting of Barrett esophagus develops via a progressive sequence of histological and molecular events. Consequently, patients with Barrett esophagus routinely undergo endoscopic surveillance for early detection of neoplasia. Histological evaluation of mucosal biopsy samples from the esophagus and gastroesophageal junction for identification of goblet cells and evaluation of the presence, grade and extent of dysplasia is the mainstay of risk assessment for these patients. This Review provides physicians with a summary of the pertinent, clinically relevant histological features of Barrett esophagus and its neoplastic complications. The histology of Barrett esophagus and the gastroesophageal junction is summarized, and an overview of information necessary to interpret pathology reports from patients either with or without endoscopic evidence of Barrett esophagus is provided to appropriately guide management of patients. Close interaction between the clinician and the pathologist is essential for proper interpretation of biopsy results and to provide optimal surveillance or treatment strategies.

Nonadenomatous dysplasia in barrett esophagus: a clinical, pathologic, and DNA content flow cytometric study

Rarely, dysplasia in Barrett's esophagus (BE) is composed of crypts lined by cuboidal-shaped cells that contain a centrally located nucleus, markedly increased nuclear/cytoplasmic ratio, but without nuclear stratification characteristic of conventional "adenomatous" dysplasia. The aim of this study was to evaluate the clinical and pathologic features, natural history, and DNA content flow cytometric abnormalities of BE patients with non-adenomatous dysplasia (NAD) in a cohort of BE patients enrolled in a prospective surveillance program. Eighteen patients with NAD identified over a 6 year period, in a cohort of 270 consecutive patients with BE and without esophageal adenocarcinoma (EA) at baseline, were evaluated for clinical and pathologic features, including association with conventional adenomatous dysplasia and EA, DNA content flow cytometric abnormalities (tetraploidy and aneuploidy) and outcome, over a mean follow-up period of 4.1 years. The findings in the 18 study patients were compared to those in the 252 remaining (control) patients without NAD. Control patients included 228 with metaplasia/indefinite for dysplasia, and 24 with conventional adenomatous dysplasia (13 low-grade, 11 high-grade). The prevalence rate of NAD in our BE cohort was 6.7% Of the 18 study patients, there were 17 were males and 1 female of mean age 66.7 years. The mean length of BE was 3.9 cm NAD foci were associated with goblet or non-goblet epithelium in 62% and 38% of cases, respectively. Ninety-four percent of patients with NAD (17/18) also had conventional adenomatous dysplasia (four with low-grade, 13 with high-grade) elsewhere in the esophagus at the same endoscopic procedure as the one that detected NAD. Patients with NAD had a significantly shorter length of BE compared to control patients with conventional adenomatous dysplasia (N=24) (p=0.03). Patients with NAD also showed a significantly higher rate of DNA content flow cytometric abnormalities compared to the entire cohort of control patients (38% vs. 11%, p=0.05). However, no significant differences regarding either flow cytometric abnormalities or progression to EA were found when the NAD patients were compared only to the 24 controls with conventional adenomatous dysplasia. NAD is a high grade histologic variant of intraepithelial neoplasia that is episodic in nature, and shows a high association with conventional adenomatous high-grade dysplasia.

A cost-utility analysis of ablative therapy for Barrett's esophagus

BACKGROUND & AIMS

Recommendations for patients with Barrett's esophagus (BE) include endoscopic surveillance with esophagectomy for early-stage cancer, although new technologies to ablate dysplasia and metaplasia are available. This study compares the cost utility of ablation with that of endoscopic surveillance strategies.

METHODS

A decision analysis model was created to examine a population of patients with BE (mean age 50), with separate analyses for patients with no dysplasia, low-grade dysplasia (LGD), or high-grade dysplasia (HGD). Strategies compared were no endoscopic surveillance; endoscopic surveillance with ablation for incident dysplasia; immediate ablation followed by endoscopic surveillance in all patients or limited to patients in whom metaplasia persisted; and esophagectomy. Ablation modalities modeled included radiofrequency, argon plasma coagulation, multipolar electrocoagulation, and photodynamic therapy.

RESULTS

Endoscopic ablation for patients with HGD could increase life expectancy by 3 quality-adjusted years at an incremental cost of <$6,000 compared with no intervention. Patients with LGD or no dysplasia can also be optimally managed with ablation, but continued surveillance after eradication of metaplasia is expensive. If ablation permanently eradicates >or=28% of LGD or 40% of nondysplastic metaplasia, ablation would be preferred to surveillance.

CONCLUSIONS

Endoscopic ablation could be the preferred strategy for managing patients with BE with HGD. Ablation might also be preferred in subjects with LGD or no dysplasia, but the cost effectiveness depends on the long-term effectiveness of ablation and whether surveillance endoscopy can be discontinued after successful ablation. As further postablation data become available, the optimal management strategy will be clarified.

Radiofrequency ablation in Barrett's esophagus with dysplasia

BACKGROUND

Barrett's esophagus, a condition of intestinal metaplasia of the esophagus, is associated with an increased risk of esophageal adenocarcinoma. We assessed whether endoscopic radiofrequency ablation could eradicate dysplastic Barrett's esophagus and decrease the rate of neoplastic progression.

METHODS

In a multicenter, sham-controlled trial, we randomly assigned 127 patients with dysplastic Barrett's esophagus in a 2:1 ratio to receive either radiofrequency ablation (ablation group) or a sham procedure (control group). Randomization was stratified according to the grade of dysplasia and the length of Barrett's esophagus. Primary outcomes at 12 months included the complete eradication of dysplasia and intestinal metaplasia.

RESULTS

In the intention-to-treat analyses, among patients with low-grade dysplasia, complete eradication of dysplasia occurred in 90.5% of those in the ablation group, as compared with 22.7% of those in the control group (P<0.001). Among patients with high-grade dysplasia, complete eradication occurred in 81.0% of those in the ablation group, as compared with 19.0% of those in the control group (P<0.001). Overall, 77.4% of patients in the ablation group had complete eradication of intestinal metaplasia, as compared with 2.3% of those in the control group (P<0.001). Patients in the ablation group had less disease progression (3.6% vs. 16.3%, P=0.03) and fewer cancers (1.2% vs. 9.3%, P=0.045). Patients reported having more chest pain after the ablation procedure than after the sham procedure. In the ablation group, one patient had upper gastrointestinal hemorrhage, and five patients (6.0%) had esophageal stricture.

CONCLUSIONS

In patients with dysplastic Barrett's esophagus, radiofrequency ablation was associated with a high rate of complete eradication of both dysplasia and intestinal metaplasia and a reduced risk of disease progression. (ClinicalTrials.gov number, NCT00282672.)

Chromosomal instability and copy number alterations in Barrett's esophagus and esophageal adenocarcinoma

PURPOSE

Chromosomal instability, as assessed by many techniques, including DNA content aneuploidy, loss of heterozygosity, and comparative genomic hybridization, has consistently been reported to be common in cancer and rare in normal tissues. Recently, a panel of chromosome instability biomarkers, including loss of heterozygosity and DNA content, has been reported to identify patients at high and low risk of progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA), but required multiple platforms for implementation. Although chromosomal instability involving amplifications and deletions of chromosome regions have been observed in nearly all cancers, copy number alterations (CNA) in premalignant tissues have not been well characterized or evaluated in cohort studies as biomarkers of cancer risk.

EXPERIMENTAL DESIGN

We examined CNAs in 98 patients having either BE or EA using Bacterial Artificial Chromosome (BAC) array comparative genomic hybridization to characterize CNAs at different stages of progression ranging from early BE to advanced EA.

RESULTS

CNAs were rare in early stages (less than high-grade dysplasia) but were progressively more frequent and larger in later stages (high-grade dysplasia and EA), including high-level amplifications. The number of CNAs correlated highly with DNA content aneuploidy. Patients whose biopsies contained CNAs involving >70 Mbp were at increased risk of progression to DNA content abnormalities or EA (hazards ratio, 4.9; 95% confidence interval, 1.6-14.8; P = 0.0047), and the risk increased as more of the genome was affected.

CONCLUSIONS

Genome-wide analysis of CNAs provides a common platform for the evaluation of chromosome instability for cancer risk assessment as well as for the identification of common regions of alteration that can be further studied for biomarker discovery.

Lugol chromoendoscopy combined with brush cytology in patients at risk for esophageal squamous cell carcinoma

BACKGROUND AND STUDY AIMS

Patients with achalasia or malignancies of the head and neck are at increased risk for esophageal squamous cell carcinoma. The discussion of a screening and surveillance program is controversial. The aim of the present study was to determine the diagnostic potential of Lugol chromoendoscopy combined with brush cytology to diagnose esophageal squamous cell carcinoma and high-grade dysplasia. Secondly, the benefit of additional biomarkers was investigated.

PATIENTS AND METHODS

A total of 61 patients (21 patients with achalasia and 40 patients with malignancies of the head and neck) were included. Chromoendoscopy with 1.2% Lugol iodine solution with targeted biopsies and brush cytology processed by digital image cytometry (DICM) and fluorescence in situ hybridization (FISH) from unstained lesions (USLs) and stained mucosa were performed.

RESULTS

Six of the 61 patients had USLs ≥2 cm. Four patients had high-grade dysplasia (HGD) or carcinoma in situ (CIS). One patient with HGD and one patient with CIS were detected only after Lugol chromoendoscopy. The sensitivity and specificity for detected HGD or CIS in USLs ≥2 cm were 100% and 96.5%. No dysplasia was found in USLs <2 cm. DNA ploidy by DNA cytometry and p53 loss of heterozygosity (LOH) by fluorescence in situ hybridization showed no additional impact on diagnostic accuracy.

CONCLUSIONS

Lugol chromoendoscopy enhances the detection rate of high-risk lesions with dysplasia or carcinoma in situ in large unstained lesions. Biomarkers such as aneuploidy and p53 LOH from brush cytology were not of additional benefit in this setting.

Screening, surveillance, and prevention for esophageal cancer

The incidence of esophageal cancer, especially esophageal adenocarcinoma, is increasing and its high mortality rate is a notable fact. Improving survival rates of this disease depend on earlier detection through screening and surveillance; however, standard diagnostic modalities, such as endoscopy with biopsy, have several limitations as screening tools, including low negative predictive value and relatively high cost. Recently developed biomarkers such as FISH and improved imaging techniques, may help overcome current problems and provide improved screening and surveillance for esophageal cancer.

Translation of an STR-based biomarker into a clinically compatible SNP-based platform for loss of heterozygosity

Loss of heterozygosity (LOH) has been shown to be a promising biomarker of cancer risk in patients with premalignant conditions. In this study we describe analytical validation in clinical biopsy samples of a SNP-based pyrosequencing panel targeting regions of LOH on chromosomes 17p and 9p including TP53 and CDKN2A tumor suppressor genes. Assays were tested for analytic specificity, sensitivity, efficiency, and reproducibility. Accuracy was evaluated by comparing SNP-based LOH results to those obtained by previously well-studied short tandem repeat polymorphisms (STRs) in DNA derived from different tissue sources including fresh-frozen endoscopic biopsies, samples from surgical resections, and formalin-fixed paraffin-embedded sections. A 17p/9p LOH panel comprised of 43 SNPs was designed to amplify with universal assay conditions in a two-step PCR and sequence-by-synthesis reaction that can be completed in two hours and 10 minutes. The methods presented can be a model for developing a SNP-based LOH approach targeted to any chromosomal region of interest for other premalignant conditions and this panel could be incorporated as part of a biomarker for cancer risk prediction, early detection, or as entry criteria for randomized trials.

Optimal conditions for successful ablation of high-grade dysplasia in Barrett's oesophagus using aminolaevulinic acid photodynamic therapy

Photodynamic therapy (PDT) using 5-aminolaevulinic acid (ALA-PDT) is an attractive alternative to PDT with porfimer sodium for the treatment of high-grade dysplasia (HGD) in Barrett's oesophagus (BO) because of the shorter duration of light photosensitivity and low risk of oesophageal stricture formation. Published results, however, show marked variation in its efficacy, and optimum treatment parameters have not been defined. This study investigated how the dose of ALA and the colour of the illuminating light influenced the biological effect. Twenty-seven patients were enrolled into a randomised controlled trial of red versus green (635 nm or 512 nm) laser light activation for the eradication of HGD with ALA-PDT in Barrett's oesophagus. A further 21 patients were subsequently treated with the most effective regimen. Regular endoscopic follow-up with quadrantic biopsies every 2 cm was performed. The primary outcome measure was eradication of HGD. Patient's receiving ALA at 30 mg/kg relapsed to HGD more than those receiving 60 mg/kg (P = 0.03). Additionally, for those treated with ALA 60 mg/kg, red laser light was more effective than green laser light (P = 0.008). Kaplan-Meier analysis of the 21 patients who were subsequently treated with this optimal regimen demonstrated an eradication rate of 89% for HGD and a cancer-free proportion of 96% at 36 months' follow-up. Using an ALA dose of 60 mg/kg activated by 1,000 J/cm red laser light, we found that ALA-PDT was a highly effective treatment for high-grade dysplasia in Barrett's oesophagus.

Cell proliferation, cell cycle abnormalities, and cancer outcome in patients with Barrett's esophagus: a long-term prospective study

PURPOSE

Elevated cellular proliferation and cell cycle abnormalities, which have been associated with premalignant lesions, may be caused by inactivation of tumor suppressor genes. We measured proliferative and cell cycle fractions of biopsies from a cohort of patients with Barrett's esophagus to better understand the role of proliferation in early neoplastic progression and the association between cell cycle dysregulation and tumor suppressor gene inactivation.

EXPERIMENTAL DESIGN

Cell proliferative fractions (determined by Ki67/DNA multiparameter flow cytometry) and cell cycle fractions (DNA content flow cytometry) were measured in 853 diploid biopsies from 362 patients with Barrett's esophagus. The inactivation status of CDKN2A and TP53 was assessed in a subset of these biopsies in a cross-sectional study. A prospective study followed 276 of the patients without detectable aneuploidy for an average of 6.3 years with esophageal adenocarcinoma as an end point.

RESULTS

Diploid S and 4N (G(2)/tetraploid) fractions were significantly higher in biopsies with TP53 mutation and loss of heterozygosity. CDKN2A inactivation was not associated with higher Ki67-positive, diploid S, G(1), or 4N fractions. High Ki67-positive and G(1)-phase fractions were not associated with the future development of esophageal adenocarcinoma (P=0.13 and P=0.15, respectively), whereas high diploid S-phase and 4N fractions were (P=0.03 and P<0.0001, respectively).

CONCLUSIONS

High Ki67-positive proliferative fractions were not associated with inactivation of CDKN2A and TP53 or future development of cancer in our cohort of patients with Barrett's esophagus. Biallelic inactivation of TP53 was associated with elevated 4N fractions, which have been associated with the future development of esophageal adenocarcinoma.

Single nucleotide polymorphism-based genome-wide chromosome copy change, loss of heterozygosity, and aneuploidy in Barrett's esophagus neoplastic progression

Chromosome copy gain, loss, and loss of heterozygosity (LOH) involving most chromosomes have been reported in many cancers; however, less is known about chromosome instability in premalignant conditions. 17p LOH and DNA content abnormalities have been previously reported to predict progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA). Here, we evaluated genome-wide chromosomal instability in multiple stages of BE and EA in whole biopsies. Forty-two patients were selected to represent different stages of progression from BE to EA. Whole BE or EA biopsies were minced, and aliquots were processed for flow cytometry and genotyped with a paired constitutive control for each patient using 33,423 single nucleotide polymorphisms (SNP). Copy gains, losses, and LOH increased in frequency and size between early- and late-stage BE (P < 0.001), with SNP abnormalities increasing from <2% to >30% in early and late stages, respectively. A set of statistically significant events was unique to either early or late, or both, stages, including previously reported and novel abnormalities. The total number of SNP alterations was highly correlated with DNA content aneuploidy and was sensitive and specific to identify patients with concurrent EA (empirical receiver operating characteristic area under the curve = 0.91). With the exception of 9p LOH, most copy gains, losses, and LOH detected in early stages of BE were smaller than those detected in later stages, and few chromosomal events were common in all stages of progression. Measures of chromosomal instability can be quantified in whole biopsies using SNP-based genotyping and have potential to be an integrated platform for cancer risk stratification in BE.

The hippo pathway in human upper gastrointestinal dysplasia and carcinoma: a novel oncogenic pathway

BACKGROUND

The Hippo (Hpo) pathway is highly conserved in humans and was originally uncovered in Drosophila as a potent regulator of inhibiting cell growth and promoting apoptosis. The Hippo pathway consists of a tumor suppressor kinase cascade that negatively regulates growth and results in inactivation of a transcriptional co-activator, Yorkie (yki). The human ortholog of Yki, the yes-associated protein (YAP), has a 31% sequence identity and similar biologic activity. The potential role of YAP in tumorigenesis was also reported in a murine genetic screen which identified a genomic amplification of YAP in hepatocellular carcinoma.

AIM

Given this pathway's critical control of cell growth, survival, proliferation, and amplification in malignancy, we wanted to explore the possible role of the Hippo pathway in human esophageal and gastric tumorigenesis.

METHOD

The expression of YAP was evaluated with immunolabeling of esophageal and gastric tissue microarrays from 169 patients, with nondysplastic, dysplastic, and malignant foci represented. Cytoplasmic and nuclear staining were scored as 0 = none, 1 < 10%, 2 = 10-50%, and 3 > 50% for the nonneoplastic, dysplastic, and malignant epithelium. Multiple scores were averaged for each patient. Expression of YAP could be seen in the proliferating compartments of nonneoplastic tissue.

RESULTS

Compared to nonneoplastic epithelium, there was a significant increase in YAP cytoplasmic and nuclear localization in high-grade dysplastic epithelium and adenocarcinoma of the esophagus. There was also a significant increase in YAP cytoplasmic and nuclear staining of gastric carcinoma and metastatic gastric disease compared to nonneoplastic gastric tissue.

CONCLUSIONS

YAP expression in the cytoplasm and nucleus is significantly increased in high-grade dysplasia and adenocarcinoma of the esophagus as well as gastric adenocarcinoma and metastatic gastric disease, suggesting a role for this recently uncovered pathway in esophageal and gastric epithelial tumorigenesis.

Management of high-grade dysplasia

High-grade dysplasia is the last stage before the development of adenocarcinoma. Despite the fact that the lesion is not yet invasive, it has tremendous potential to become malignant. The approach to the disease has clinicians divided between immediate intervention with surgical resection or continued endoscopic surveillance proof of the unclear natural history. Much knowledge has been acquired recently regarding application of surveillance and outcomes of esophageal resection. Also, many endoscopic techniques for treating high-grade dysplasia have been studied in depth. Results on their safety, efficacy, and complication rates have recently become available. This review analyzes the progress in the understanding and treatment of high-grade dysplasia during the past 24 to 36 months and examines how this new information plays a role in the disease's treatment algorithm.

HER-2 overexpression/amplification in Barrett's oesophagus predicts early transition from dysplasia to adenocarcinoma: a clinico-pathologic study

Barrett's oesophagus (BO) is the primary precursor lesion for oesophageal adenocarcinoma (ADC). The natural history of metaplasia-dysplasia-carcinoma sequence remains largely unknown. HER2/neu oncogene results overexpressed/amplified in preneoplastic lesions and in ADC of the oesophagus and it has been associated with poor prognosis. Our aim was to evaluate the role of HER2 overexpression/amplification in predicting the conversion from precursor lesions to ADC. We retrospectively evaluated by univariate analysis of single variables clinical records and histological specimens of 21 patients with a confirmed diagnosis of BO and/or oesophageal dysplasia. Clinical variables included age, gender, alcohol and smoking intake, presence of symptoms (pyrosis, disphagia) and endoscopic features (length). HER2 status was studied by immunohistochemistry and fluorescence in situ hybridization (FISH) on paraffin-embedded tissue. The end-points were the occurrence of progression and the time-to-progression (TTP) from the initial histologic lesion to the worst pathological pattern. Median age at diagnosis was 63 years (range 37-84). BO median length was 4.5 cm. Progression occurred in 11 of 21 patients and median TTP was 24 months. HER2 was overexpressed/amplified in 8 of 21 (38%) patients. HER2 overexpression/ amplification and the presence of dysplasia were statistically associated with progression (P= 0.038). This study provides evidence for a possible role of HER2 in the transition from dysplasia to ADC of the oesophagus. This fact could help in identifying patients at high risk of malignant transformation.

Barrett's esophagus and the increasing role of endoluminal therapy

Barrett's esophagus, or the presence of specialized intestinal mucosa in the esophagus that has a malignant potential, has experienced a rapid increase in diagnosis and prevalence over the past few decades. Once thought to progress to adenocarcinoma in an orderly sequence of increasing dysplasia, recent data suggest the process can be more random. In combination with targeted surveillance endoscopy, recent improvements in technology have aided endoluminal therapy in becoming a cost-effective adjunct to medication. When used in combination, in particular, these ablative therapies have become suitable, if not preferable, alternatives to surgery in many patients.

Utility of biomarkers in prediction of response to ablative therapy in Barrett's esophagus

BACKGROUND & AIMS

Photodynamic therapy (PDT) has been shown to be effective in the treatment of high-grade dysplasia (HGD)/mucosal carcinoma in Barrett's esophagus (BE). Substantial proportions of patients do not respond to PDT or progress to carcinoma despite PDT. The role of biomarkers in predicting response to PDT is unknown. We aimed to determine if biomarkers known to be associated with neoplasia in BE can predict loss of dysplasia in patients treated with ablative therapy for HGD/intramucosal cancer.

METHODS

Patients with BE and HGD/intramucosal cancer were studied prospectively from 2002 to 2006. Biomarkers were assessed using fluorescence in situ hybridization performed on cytology specimens, for region-specific and centromeric probes. Patients were treated with PDT using cylindric diffusing fibers (wavelength, 630 nm; energy, 200 J/cm fiber). Univariate and multiple variable logistic regression was performed to determine predictors of response to PDT.

RESULTS

A total of 126 consecutive patients (71 who underwent PDT and 55 patients who did not undergo PDT and were under surveillance, to adjust for the natural history of HGD), were included in this study. Fifty (40%) patients were responders (no dysplasia or carcinoma) at 3 months after PDT. On multiple variable analysis, P16 allelic loss (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.10-0.96) predicted decreased response to PDT. BE segment length (OR, 0.71; 95% CI, 0.59-0.85), and performance of PDT (OR, 7.17; 95% CI, 2.50-20.53) were other independent predictors of loss of dysplasia.

CONCLUSIONS

p16 loss detected by fluorescence in situ hybridization can help predict loss of dysplasia in patients with BE and HGD/mucosal cancer. Biomarkers may help in the selection of appropriate therapy for patients and improve treatment outcomes.

Correlation of histology with biomarker status after photodynamic therapy in Barrett esophagus

BACKGROUND

Currently, histology is used as the endpoint to define success with photodynamic therapy (PDT) in patients with high-grade dysplasia (HGD). Recurrences despite 'successful' ablation are common. The role of biomarkers in assessing response to PDT remains undefined. The objectives of the current study were 1) to assess biomarkers in a prospective cohort of patients with HGD/mucosal cancer before and after PDT and 2) to correlate biomarker status after PDT with histology.

METHODS

Patients who underwent PDT for HGD/mucosal cancer were studied prospectively. All patients underwent esophagogastroduodenoscopy, 4-quadrant biopsies every centimeter, endoscopic mucosal resection of visible nodules, and endoscopic ultrasound. Cytology samples were obtained by using standard cytology brushes. Biomarkers were assessed by using fluorescence in situ hybridization (FISH). The biomarkers that were assessed included loss of 9p21 (site of the p16 gene) and 17p13.1 (site of the p53 gene) loci; gains of the 8q24(c-myc), 17q (HER2-neu), and 20q13 loci; and multiple gains. Patients received PDT 48 hours after the administration of sodium porfimer. Demographic and clinical variables were collected prospectively. Patients were followed with endoscopy and repeat cytology for biomarkers. The McNemar test was used to compare biomarker proportions before and after PDT.

RESULTS

Thirty-one patients were studied. The median patient age was 66 years (interquartile range [IQR], 56-73 years), and 28 patients (88%) were men. The mean Barrett segment length was 5 cm (standard error of the mean, 0.5 cm). Post-PDT biomarkers were obtained after a median duration of 9 months (IQR, 3-12 months). There was a statistically significant decrease in the proportion of several biomarkers assessed after PDT. Six patients without HGD after PDT still had positive FISH results for 1 or more biomarkers: of these, 2 patients (33%) developed recurrent HGD.

CONCLUSIONS

In this initial study, histologic downgrading of dysplasia after PDT was associated with the loss of biomarkers that have been associated with progression of neoplasia in Barrett esophagus. Patients with persistently positive biomarkers appeared to be at a higher risk of recurrent HGD. These findings should be confirmed in a larger study.

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

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

Systematic four-quadrant biopsy detects Barrett's dysplasia in more patients than nonsystematic biopsy

AIMS

To compare detection of Barrett's dysplasia and adenocarcinoma by systematic versus nonsystematic surveillance biopsy protocols.

METHODS

Upper GI consultation and open-access endoscopy are provided jointly at Glasgow Royal Infirmary by medical and surgical teams. The surgical team adopted annual systematic four-quadrant biopsy Barrett's surveillance in 1995. The medical team continued annual Barrett's surveillance with nonsystematic biopsy until 2004. We compare detection of Barrett's dysplasia and esophageal adenocarcinoma in unselected patients by these two biopsy strategies over 10 yr. All patients had > or = 3 cm Barrett's esophagus and histological proof of intestinal metaplasia. Patients referred for dysplasia management or with prevalent adenocarcinoma were excluded. Cohort A (N = 180) had four-quadrant biopsy every 2 cm while cohort B (N = 182) had nonsystematic biopsies.

RESULTS

Cohort A versus cohort B: Median number of biopsies per endoscopy: 16 versus 4. Prevalence of low-grade dysplasia (per patient): 18.9% versus 1.6% (P << 0.001). Prevalence of high-grade dysplasia: 2.8% versus 0% (P = 0.03). Incidence of low-grade dysplasia: 2.2% versus 6.6% (NS). Incidence of high-grade dysplasia: 2.8% versus 0% (P = 0.03). Nine cohort A patients (total 5%, 1.4% per patient-year) were treated for HGD (eight endoscopically, one by esophagectomy). Two had intramucosal adenocarcinoma. No cohort A patient developed advanced cancer but three cohort B patients developed and died of invasive Barrett's adenocarcinoma (0.6% per patient-year).

CONCLUSIONS

Patient age, gender, Barrett's segment length, and follow-up were similar (though not identical) in both cohorts, but confounding seems unlikely to account for a 13-fold difference in detection of prevalent dysplasia between the two groups. Our data support the hypothesis that systematic four-quadrant biopsy is considerably more effective than nonsystematic biopsy sampling in detecting Barrett's dysplasia and early adenocarcinoma. Greater biopsy numbers and the systematic pattern of biopsy taking may both contribute to this greater effectiveness.

Dietary supplement use and risk of neoplastic progression in esophageal adenocarcinoma: a prospective study

The incidence of esophageal adenocarcinoma (EA) and its precursor condition, Barrett's esophagus, has risen rapidly in the United States for reasons that are not fully understood. Therefore, we evaluated the association between use of supplemental vitamins and minerals and risk of neoplastic progression of Barrett's esophagus and EA. The Seattle Barrett's Esophagus Program is a prospective study based on 339 men and women with histologically confirmed Barrett's esophagus. Participants underwent baseline and periodic follow-up exams, which included endoscopy and self-administered questionnaires on diet, supplement use, and lifestyle characteristics. Use of multivitamins and 4 individual supplements was calculated using time-weighted averages of reported use over the observational period. Cox proportional-hazards models were used to calculate hazard ratios (HR) for each endpoint: EA, tetraploidy, and aneuploidy. During a mean follow-up of 5 yr, there were 37 cases of EA, 42 cases of tetraploidy, and 34 cases of aneuploidy. After controlling for multiple covariates including diet, nonsteroidal anti-inflammatory drug use, obesity, and smoking, participants who took 1 or more multivitamin pills/day had a significantly decreased risk of tetraploidy [HR = 0.19; 95% confidence interval (CI) = 0.08-0.47) and EA (HR = 0.38; 95% CI = 0.15-0.99] compared to those not taking multivitamins. Significant inverse associations were also observed between risk of EA and supplemental vitamin C (> or = 250 mg vs. none: HR = 0.25; 95% CI = 0.11-0.58) and vitamin E (> or = 180 mg vs. none: HR = 0.25; 95% CI = 0.10-0.60). In this cohort study, use of multivitamins and single antioxidant supplements was associated with a significantly reduced risk of EA and markers of neoplastic progression among individuals with Barrett's esophagus.

Barrett's Esophagus: Diagnosis, Screening, Surveillance, and Controversies

Barrett's esophagus (BE) is a frequent complication of gastroesophageal reflux disease, an acquired condition resulting from persistent mucosal injury to the esophagus. The incidence of Barrett's metaplasia and Barrett's adenocarcinoma has been increasing, but the prognosis of Barrett's adenocarcinoma is worse because individuals present at a late stage. Attempts have been made to intervene at early stage using surveillance programmes, although proof of efficacy of endoscopic surveillance is lacking. There is much to be learned about BE. Whether adequate control of gastroesophageal reflux early in the disease alters the natural history of Barrett's change once it has developed remains unanswered. Thus there is great need for carefully designed large randomised controlled trials to address these issues in order to determine how best to manage patients with BE. The AspECT and BOSS clinical trials proride this basis.

Barrett's esophagus: Incidence, etiology, pathophysiology, prevention and treatment

Barrett's esophagus is a metaplastic alteration of the normal esophageal epithelium that is detected on endoscopic examination and pathologically confirmed by the presence of intestinal metaplasia on biopsy. Its major significance is as a predisposing factor for esophageal adenocarcinoma, which carries a high mortality rate and a rapidly growing incidence in the United States. Detection of Barrett's esophagus allows for endoscopic surveillance in order to detect the potential development of dysplasia and early cancer before symptoms develop, and thereby significantly increases treatment options and may lower mortality from esophageal adenocarcinoma. Much current work in the field is aimed at reducing the risk of progression from Barrett's esophagus to cancer, and in the identification of biomarkers that may predict progression towards cancer. Barrett's esophagus is present in 10%-20% of patients with gastroesophageal reflux disease (GERD) and has also been detected in patients who deny classic GERD symptoms and are undergoing endoscopy for other indications. We used an evidence-based approach to describe treatment options for patients with Barrett's esophagus.

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

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

Endoscopic mucosal resection of Barrett's oesophagus containing dysplasia or intramucosal cancer

Barrett's oesophagus is premalignant. Oesophagectomy is traditionally regarded as the standard treatment option in the presence of high grade intraepithelial neoplasia or intramucosal cancer. However, oesophagectomy is associated with high rates of mortality and morbidity. Endoscopic ablative therapies are limited by the lack of tissue for histological assessment, and the ablation may be incomplete. Endoscopic mucosal resection is an alternative to surgery in the management of high grade intraepithelial neoplasia and intramucosal cancer. It is less invasive than surgery and, unlike ablative treatments, provides tissue for histological assessment. This review will cover the indications, techniques and results of endoscopic mucosal resection.

Molecular changes in the progression of Barrett's oesophagus

Barrett's oesophagus is a frequent complication of gastro-oesophageal reflux disease predicting oesophageal adenocarcinoma. The majority of Barrett's patients will not develop cancer, so that specific methods of identification of those at risk are required. Recent molecular studies have identified a selection of candidate biomarkers that need validation in prospective studies. They reflect various changes in cell behaviour during neoplastic progression. The ASPECT trial in the UK aims to establish whether chemoprevention with aspirin and a proton pump inhibitor will reduce adenocarcinoma development and mortality in patients with Barrett's oesophagus. It will also validate biomarkers for progression and clinical response and further study disease pathogenesis.

Grading of dysplasia in Barrett's oesophagus: substantial interobserver variation between general and gastrointestinal pathologists

AIMS

To determine interobserver variation in grading of dysplasia in Barrett's oesophagus (BO) between non-expert general pathologists and expert gastrointestinal pathologists on the one hand and between expert pathologists on the other hand.

METHODS AND RESULTS

In this prospective multicentre study, non-expert and expert pathologists graded biopsy specimens of 920 patients with endoscopic BO, which were blindly reviewed by one member of a panel of expert pathologists (panel experts) and by a second panel expert in case of disagreement on dysplasia grade. Agreement between two of three pathologists was established as the final diagnosis. Analysis was performed by kappa statistics. Due to absence of intestinal metaplasia, 127/920 (14%) patients were excluded. The interobserver agreement for dysplasia [no dysplasia (ND) versus indefinite for dysplasia/low-grade dysplasia (IND/LGD) versus high-grade dysplasia (HGD)/adenocarcinoma (AC)] between non-experts and first panel experts and between initial experts and first panel experts was fair (kappa = 0.24 and kappa = 0.27, respectively), and substantial for differentiation of HGD/AC from ND/IND/LGD (kappa = 0.62 and kappa = 0.58, respectively).

CONCLUSIONS

There was considerable interobserver variability in the interpretation of ND or IND/LGD in BO between non-experts and experts, but also between expert pathologists. This suggests that less subjective markers are needed to determine the risk of developing AC in BO.

How light dosimetry influences the efficacy of photodynamic therapy with 5-aminolaevulinic acid for ablation of high-grade dysplasia in Barrett's esophagus

Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) is a novel treatment for high-grade dysplasia (HGD) in Barrett's esophagus (BE). Our aim was to evaluate the effectiveness of differing light doses. Patients with HGD in BE received oral ALA (60 mg/kg) activated by low (500 J/cm), medium (750 J/cm), high (1,000 J/cm), or highest (1,000 J/cm x2) light dose at 635 nm. Follow-up was by regular endoscopy with quadrantic biopsies. Twenty-four patients were treated. Successful eradication of HGD was significantly correlated with light dose (log rank, p < 0.01). Six of eight patients (75%) treated with the highest light dose, one of two treated with high dose (50%), two of nine (22%) receiving medium light dose, and zero of five receiving low light dose had successful eradication of HGD (median follow-up 45 months, range 1-78 months). No skin photosensitivity or esophageal strictures occurred. The efficacy of ALA-PDT for eradication of HGD in BE is closely related to the light dose used. With a drug dose of 60 mg/kg and light at 635 nm, we recommend a minimum light dose of 1,000 J/cm of esophagus. This dose appears safe.

Long-term survival following endoscopic and surgical treatment of high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Photodynamic therapy (PDT) for high-grade dysplasia (HGD) in Barrett's esophagus is a Food and Drug Administration-approved alternative to esophagectomy. Critical information regarding overall survival of patients followed up long-term after these therapies is lacking. Our aim was to compare the long-term survival of patients treated with PDT with patients treated with esophagectomy.

METHODS

We reviewed records of patients with HGD seen at our institution between 1994 and 2004. PDT was performed 48 hours following the intravenous administration of a photosensitizer using light at 630 nm. Esophagectomy was performed by either transhiatal or transthoracic approaches by experienced surgeons. We excluded all patients with evidence of cancer on biopsy specimens. Vital status and death date information was queried using an institutionally approved Internet research and location service. Statistical analysis was performed using Kaplan-Meier curves and Cox proportional hazards ratios.

RESULTS

A total of 199 patients were identified. A total of 129 patients (65%) were treated with PDT and 70 (35%) with esophagectomy. Overall mortality in the PDT group was 9% (11/129) and in the surgery group was 8.5% (6/70) over a median follow-up period of 59 +/- 2.7 months for the PDT group and 61 +/- 5.8 months for the surgery group. Overall survival was similar between the 2 groups (Wilcoxon test = 0.0924; P = .76). Treatment modality was not a significant predictor of mortality on multivariate analysis.

CONCLUSIONS

Overall mortality and long-term survival in patients with HGD treated with PDT appears to be comparable to that of patients treated with esophagectomy.

Extent of low-grade dysplasia is a risk factor for the development of esophageal adenocarcinoma in Barrett's esophagus

OBJECTIVES

Previous studies that evaluated extent of high-grade dysplasia (HGD) as a risk factor for esophageal adenocarcinoma (EA) in Barrett's esophagus (BE) were conflicting, and no prior study has evaluated extent of low-grade dysplasia (LGD) as a risk factor. The aim of this discovery study was to evaluate the hypothesis that extent of LGD and HGD are risk factors for progression to EA.

METHODS

We evaluated baseline biopsies from 77 BE patients with dysplasia including 44 who progressed to EA and 33 who did not progress during follow-up. The total numbers of LGD and HGD crypts were determined separately by counting all crypts and the extent of LGD, HGD, and total dysplasia were correlated with EA outcome.

RESULTS

Thirty-one and 46 patients had a maximum diagnosis of LGD and HGD, respectively. When the crypts were stratified by dysplasia grade, the mean number of LGD crypts per patient was borderline higher in progressors (93.9) compared with nonprogressors (41.2, P= 0.07), and the mean proportion of LGD crypts per patient was significantly higher in progressors (46.4%vs 26.0%, P= 0.037). Neither the mean number of HGD crypts per patient (P= 0.14) nor the mean proportion of HGD crypts per patient (P= 0.20) was significantly associated with EA outcome.

CONCLUSIONS

The extent of LGD is a significant risk factor for the development of EA in BE in this study. Although the presence of HGD is significantly associated with a greater relative risk for development of EA, the extent of HGD was not an independent risk factor for progression.

Extent of low-grade dysplasia in Barrett's esophagus: is it useful for risk stratification?

Low-grade dysplasia remains one of the great enigmas of Barrett's esophagus. Limited information is available on the natural history of this lesion, and studies suggest that cancer risk in patients with low-grade dysplasia is intermediate between that of intestinal metaplasia without dysplasia and high-grade dysplasia. Natural history studies of low-grade dysplasia are hampered by problems with interobserver variability among pathologists and sampling variability among endoscopists. To date, the extent of low-grade dysplasia has not been examined as a potential risk factor for the subsequent development of adenocarcinoma. Srivastava et al., in this issue of the American Journal of Gastroenterology, found that the extent of low-grade dysplasia, as measured by several different methods, was a risk factor for progression to cancer. While these findings are novel and provocative, it is premature to request your pathologist to count the number of crypts or biopsies with low-grade dysplasia just yet. However, these findings, if confirmed by studies utilizing a simpler measure of the extent of low-grade dysplasia, may help us determine the prognostic significance of this lesion in the future.

NSAIDs modulate CDKN2A, TP53, and DNA content risk for progression to esophageal adenocarcinoma

BACKGROUND

Somatic genetic CDKN2A, TP53, and DNA content abnormalities are common in many human cancers and their precursors, including esophageal adenocarcinoma (EA) and Barrett's esophagus (BE), conditions for which aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) have been proposed as possible chemopreventive agents; however, little is known about the ability of a biomarker panel to predict progression to cancer nor how NSAID use may modulate progression. We aimed to evaluate somatic genetic abnormalities with NSAIDs as predictors of EA in a prospective cohort study of patients with BE.

METHODS AND FINDINGS

Esophageal biopsies from 243 patients with BE were evaluated at baseline for TP53 and CDKN2A (p16) alterations, tetraploidy, and aneuploidy using sequencing; loss of heterozygosity (LOH); methylation-specific PCR; and flow cytometry. At 10 y, all abnormalities, except CDKN2A mutation and methylation, contributed to EA risk significantly by univariate analysis, ranging from 17p LOH (relative risk [RR] = 10.6; 95% confidence interval [CI] 5.2-21.3, p < 0.001) to 9p LOH (RR = 2.6; 95% CI 1.1-6.0, p = 0.03). A panel of abnormalities including 17p LOH, DNA content tetraploidy and aneuploidy, and 9p LOH was the best predictor of EA (RR = 38.7; 95% CI 10.8-138.5, p < 0.001). Patients with no baseline abnormality had a 12% 10-y cumulative EA incidence, whereas patients with 17p LOH, DNA content abnormalities, and 9p LOH had at least a 79.1% 10-y EA incidence. In patients with zero, one, two, or three baseline panel abnormalities, there was a significant trend toward EA risk reduction among NSAID users compared to nonusers (p = 0.01). The strongest protective effect was seen in participants with multiple genetic abnormalities, with NSAID nonusers having an observed 10-y EA risk of 79%, compared to 30% for NSAID users (p < 0.001).

CONCLUSIONS

A combination of 17p LOH, 9p LOH, and DNA content abnormalities provided better EA risk prediction than any single TP53, CDKN2A, or DNA content lesion alone. NSAIDs are associated with reduced EA risk, especially in patients with multiple high-risk molecular abnormalities.

Beyond Field Effect: Analysis of Shrunken Centroids in Normal Esophageal Epithelia Detects Concomitant Esophageal Adenocarcinoma

BACKGROUND AND AIMS: Because of the extremely low neoplastic progression rate in Barrett's esophagus, it is difficult to diagnose patients with concomitant adenocarcinoma early in their disease course. If biomarkers existed in normal squamous esophageal epithelium to identify patients with concomitant esophageal adenocarcinoma, potential applications would be far-reaching. The aim of the current study was to identify global gene expression patterns in normal esophageal epithelium capable of revealing simultaneous esophageal adenocarcinoma, even located remotely in the esophagus. METHODS: Tissues comprised normal esophageal epithelia from 9 patients with esophageal adenocarcinoma, 8 patients lacking esophageal adenocarcinoma or Barrett's, and 6 patients with Barrett's esophagus alone. cDNA microarrays were performed, and pattern recognition in each of these subgroups was achieved using shrunken nearest centroid predictors. RESULTS: Our method accurately discriminated normal esophageal epithelia of 8/8 patients without esophageal adenocarcinoma or Barrett's esophagus and of 6/6 patients with Barrett's esophagus alone from normal esophageal epithelia of 9/9 patients with Barrett's esophagus and concomitant esophageal adenocarcinoma. Moreover, we identified genes differentially expressed between the above subgroups. Thus, based on their corresponding normal esophageal epithelia alone, our method accurately diagnosed patients who had concomitant esophageal adenocarcinoma. CONCLUSIONS: These global gene expression patterns, along with individual genes culled from them, represent potential biomarkers for the early diagnosis of esophageal adenocarcinoma from normal esophageal epithelia. Genes discovered in normal esophagus that are differentially expressed in patients with vs. without esophageal adenocarcinoma merit further pursuit in molecular genetic, functional, and therapeutic interventional studies.

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.

Diagnosis and grading of dysplasia in Barrett's oesophagus

This review focuses on the pathological features of dysplasia in Barrett's oesophagus. Two categorisation schemes are used for grading dysplasia in the gastrointestinal tract, including Barrett's oesophagus. The inflammatory bowel disease dysplasia morphology study group system is the one most commonly used in the USA. However, some European and most far Eastern countries use the Vienna classification system, which uses the term "non-invasive neoplasia" instead of low-grade dysplasia (LGD) or high-grade dysplasia (HGD) and also uses the term "suspicious for invasive carcinoma" for lesions that show equivocal cytological or architectural features of tissue invasion. The degree of dysplasia is based on a combination of cytological and architectural atypia. However, the precise number of HGD crypts that is necessary to upgrade a biopsy from LGD to HGD has never been investigated and varies widely among expert gastrointestinal pathologists. The extent of dysplasia, particularly LGD, has also been recognised recently as an important prognostic parameter in Barrett's oesophagus. Other problematic areas of dysplasia interpretation include differentiation of regenerating epithelium versus LGD and separating HGD from carcinoma. Dysplasia associated with macroscopically visible lesions, such as ulcers, nodules or polyps, carry a high risk of synchronous or metachronous adenocarcinoma. Recently, immunostaining for alpha-methylacyl-CoA-racemase has been shown to have a high degree of specificity for detection of dysplasia in Barrett's oesophagus and may be used to help distinguish negative from positive biopsies in this condition. In this review, the problematic areas in dysplasia interpretation are outlined and a specific approach to these issues is discussed.

Endoscopic mucosal resection of large hyperplastic polyps in 3 patients with Barrett’s esophagus

AIM: To report the endoscopic treatment of large hyperplastic polyps of the esophagus and esophago-gastric junction (EGJ) associated with Barrett’s esophagus (BE) with low-grade dysplasia (LGD), by endoscopic mucosal resection (EMR).

METHODS: Cap fitted EMR (EMR-C) was performed in 3 patients with hyperplastic-inflammatory polyps (HIPs) and BE.

RESULTS: The polyps were successfully removed in the 3 patients. In two patients, with short segment BE (SSBE) (≤ 3 cm), the metaplastic tissue was completely excised. A 2 cm circumferential EMR was performed in one patient with a polyp involving the whole EGJ. A simultaneous EMR-C of a BE-associated polypoid dysplastic lesion measuring 1 cm x 10 cm, was also carried out. In the two patients, histologic assessment detected LGD in BE. No complications occurred. Complete neosquamous re-epithelialization occurred in the two patients with SSBE. An esophageal recurrence occurred in the remaining one and was successfully retreated by EMR.

CONCLUSION: EMR-C appears to be a safe and effective method for treating benign esophageal mucosal lesions, allowing also the complete removal of SSBE.

Reproducible two-dimensional capillary electrophoresis analysis of Barrett's esophagus tissues

We have constructed a high-speed, two-dimensional capillary electrophoresis system with a compact and high-sensitivity fluorescence detector. This instrument is used for the rapid and reproducible separations of Barrett's esophagus tissue homogenates. Proteins and biogenic amines are labeled with the fluorogenic reagent 3-(2-furoyl)quinoline-2-carboxaldehyde. Labeled biomolecules are separated sequentially in two capillaries. The first capillary employs capillary sieving electrophoresis using a replaceable sieving matrix. Fractions are successively transferred to a second capillary where they undergo additional separation by micellar electrokinetic capillary chromatography. The comprehensive two-dimensional separation requires 60 min. Within-day migration time reproducibility is better than 1% in both dimensions for the 50 most intense features. Between-day migration time precision is 1.3% for CSE and better than 0.6% for MECC. Biopsies were obtained from the squamous epithelium in the proximal tubular esophagus, Barrett's epithelium from the distal esophagus, and fundus region of the stomach from each of three Barrett's esophagus patients with informed consent. We identified 18 features from the homogenate profiles as biogenic amines and amino acids. For each of the patients, Barrett's biopsies had more than 5 times the levels of phenylalanine and alanine as compared to squamous tissues. The patient with high-grade dysplasia shows the highest concentrations for 13 of the amino acids across all tissue types. Concentrations of glycine are 40 times higher in squamous biopsies compared to Barrett's and fundal biopsies from the patient with high-grade dysplasia. These results suggest that two-dimensional capillary electrophoresis may be of value for the rapid characterization of endoscopic and surgical biopsies.

Photodynamic therapy in Barrett's esophagus: results of treatment of 17 patients

BACKGROUND

Barrett's esophagus (BE) with dysplasia may progress to esophageal adenocarcinoma. Photodynamic therapy is a promising treatment for BE.

OBJECTIVE

To determine if photodynamic therapy is an acceptable alternative to esophagectomy in BE patients with high-grade dysplasia or early adenocarcinoma.

METHODS

Seventeen patients were treated with photodynamic therapy for BE and high-grade dysplasia or early esophageal adenocarcinoma. Patients with residual Barrett's epithelium were treated with supplemental argon plasma coagulation or potassium titanyl phosphate laser. Patients underwent follow-up endoscopy three, six, nine and 12 months post-treatment, then every six to 12 months. Mean follow-up was 21 months.

RESULTS

High-grade dysplasia or early adenocarcinoma was completely eliminated in nine of 15 (60%) patients. High-grade dysplasia was downgraded in one patient, persisted in one patient and progressed in four patients. Two patients with early esophageal adenocarcinoma were nonresponders. Complications included stricture, sunburn, urticaria, small pleural effusions, esophageal spasm and transient atrial fibrillation.

CONCLUSIONS

Photodynamic therapy with supplemental ablation is a good, noninvasive therapy for elimination of high-grade dysplasia and early adenocarcinoma in BE. Failure to eliminate dysplastic epithelium occurred in 40% of the patients, thereby necessitating careful follow-up.

Elastic scattering spectroscopy accurately detects high grade dysplasia and cancer in Barrett's oesophagus

BACKGROUND AND AIMS

Endoscopic surveillance of Barrett's oesophagus currently relies on multiple random biopsies. This approach is time consuming, has a poor diagnostic yield, and significant interobserver variability. Elastic scattering spectroscopy is a real time in vivo optical technique which detects changes in the physical properties of cells. The aim of this study was to assess the potential for elastic scattering to detect high grade dysplasia or cancer within Barrett's oesophagus.

METHODS

Elastic scattering spectroscopy measurements collected in vivo were matched with histological specimens taken from identical sites within Barrett's oesophagus. All biopsies were reviewed by three gastrointestinal pathologists and defined as either "low risk" (non-dysplastic or low grade dysplasia) or "high risk" (high grade dysplasia or cancer). Two different statistical approaches (leave one out and block validation) were used to validate the model.

RESULTS

A total of 181 matched biopsy sites from 81 patients, where histopathological consensus was reached, were analysed. There was good pathologist agreement in differentiating high grade dysplasia and cancer from other pathology (kappa = 0.72). Elastic scattering spectroscopy detected high risk sites with 92% sensitivity and 60% specificity and differentiated high risk sites from inflammation with a sensitivity and specificity of 79%. If used to target biopsies during endoscopy, the number of low risk biopsies taken would decrease by 60% with minimal loss of accuracy. A negative spectroscopy result would exclude high grade dysplasia or cancer with an accuracy of >99.5%.

CONCLUSIONS

These preliminary results show that elastic scattering spectroscopy has the potential to target conventional biopsies in Barrett's surveillance saving significant endoscopist and pathologist time with consequent financial savings. This technique now requires validation in prospective studies.

The effects of esomeprazole combined with aspirin or rofecoxib on prostaglandin E2 production in patients with Barrett's oesophagus

BACKGROUND

Reducing mucosal cyclo-oxygenase-2 and prostaglandin E(2) production and suppressing intraoesophageal acid may be effective chemopreventive strategies in patients with Barrett's oesophagus.

AIM

To compare the effects of aspirin and rofecoxib when administered with esomeprazole on prostaglandin E(2) production, cyclo-oxygenase-2 expression and proliferating cell nuclear antigen expression in patients with Barrett's oesophagus.

METHODS

This exploratory, multicentre, randomized, open-label, four-way crossover study in 45 patients with Barrett's oesophagus evaluated prostaglandin E(2) content, proliferating cell nuclear antigen expression, and cyclo-oxygenase-2 expression after 10 days of sequential treatments with: esomeprazole 40 mg twice daily plus aspirin 325 mg once daily (E40 b.d. + A325); E40 b.d. plus rofecoxib 25 mg once daily (E40 b.d. + R25); E40 b.d.; and rofecoxib 25 mg once daily (R25).

RESULTS

Prostaglandin E(2) content reduction in Barrett's oesophagus tissue was significantly greater with E40 b.d. + A325 compared with E40 b.d. + R25, E40 b.d. or R25 (P < 0.05). All treatments containing E40 b.d. significantly decreased proliferating cell nuclear antigen expression from baseline (P < 0.05). None of the treatments significantly reduced cyclo-oxygenase-2 expression.

CONCLUSIONS

The combined treatment of esomeprazole 40 mg b.d. and aspirin 325 mg significantly decreased mucosal prostaglandin E(2) content and all treatments containing esomeprazole significantly reduced proliferating cell nuclear antigen expression in patients with Barrett's oesophagus.

Biomarkers in the molecular pathogenesis of esophageal (Barrett) adenocarcinoma

Since the early 1970s, a dramatic change has occurred in the epidemiology of esophageal malignancy in both North America and Europe: the incidence of adenocarcinomas of the lower esophagus and esophagogastric junction is increasing. Several lifestyle factors are implicated in this change, including gastroesophageal reflux disease (GERD). Primary esophageal adenocarcinomas are thought to arise from Barrett esophagus, an acquired condition in which the normal esophageal squamous epithelium is replaced by a specialized metaplastic columnar-cell-lined epithelium.Today, gerd is recognized as an important risk factor in Barrett esophagus. Progression of Barrett esophagus to invasive adenocarcinoma is reflected histologically by the metaplasia-dysplasia-carcinoma sequence. Although several molecular alterations associated with progression of Barrett esophagus to invasive adenocarcinoma have been identified, relatively few will ultimately have clinical application. Currently, the histologic finding of high-grade dysplasia remains the most reliable predictor of progression to invasive esophageal adenocarcinoma. However other promising molecular biomarkers include aneuploidy; 17p loss of heterozygosity, which implicates the TP53 tumour suppressor gene; cyclin D1 protein overexpression; and p16 alterations. It is anticipated that models incorporating combinations of objective scores of sociodemographic and lifestyle risk factors (that is, age, sex, body mass index), severity of gerd, endoscopic and histologic findings, and a panel of biomarkers will be developed to better identify patients with Barrett esophagus at increased risk for malignant progression, leading to more rational endoscopic surveillance and screening programs.

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.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.