Epigenetic patterns in the progression of esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) arises after normal squamous mucosa undergoes metaplasia to specialized columnar epithelium (intestinal metaplasia or Barrett's esophagus), which can then ultimately progress to dysplasia and subsequent malignancy. Epigenetic studies of this model have thus far been limited to the DNA methylation analysis of a few genes. In this study, we analyzed a panel of 20 genes using a quantitative, high-throughput methylation assay, METHYLIGHT: We used this broader approach to gain insight into concordant methylation behavior between genes and to generate epigenomic fingerprints for the different histological stages of EAC. Our study included a total of 104 tissue specimens from 51 patients with different stages of Barrett's esophagus and/or associated adenocarcinoma. We screened 84 of these samples with the full panel of 20 genes and found distinct classes of methylation patterns in the different types of tissue. The most informative genes were those with an intermediate frequency of significant hypermethylation [ranging from 15% (CDKN2A) to 60% (MGMT) of the samples]. This group could be further subdivided into three classes, according to the absence (CDKN2A, ESR1, and MYOD1) or presence (CALCA, MGMT, and TIMP3) of methylation in normal esophageal mucosa and stomach, or the infrequent methylation of normal esophageal mucosa accompanied by methylation in all normal stomach samples (APC). The other genes were less informative, because the frequency of hypermethylation was below 5% (ARF, CDH1, CDKN2B, GSTP1, MLH1, PTGS2, and THBS1), completely absent (CTNNB1, RB1, TGFBR2, and TYMS1), or ubiquitous (HIC1 and MTHFR), regardless of tissue type. Each class undergoes unique epigenetic changes at different steps of disease progression of EAC, suggesting a step-wise loss of multiple protective barriers against CpG island hypermethylation. The aberrant hypermethylation occurs at many different loci in the same tissues, suggestive of an overall deregulation of methylation control in EAC tumorigenesis. However, we did not find evidence for a distinct group of tumors with a CpG island methylator phenotype. Finally, we found that normal and metaplastic tissues from patients with evidence of associated dysplasia or cancer had a significantly higher incidence of hypermethylation than similar tissues from patients with no further progression of their disease. The fact that the samples from these two groups of patients were histologically indistinguishable, yet molecularly distinct, suggests that the occurrence of such hypermethylation may provide a clinical tool to identify patients with premalignant Barrett's who are at risk for further progression.

Evaluation of the intestinal microflora in the rat model for esophageal adenocarcinoma

Surgically induced duodenal reflux results in cancer development in the rat esophagus. One proposed mechanism of carcinogenesis relies on the production of carcinogens in the presence of bacterial overgrowth. Against this background, intestinal microflora in the rat jejunum was analyzed before and after reflux-inducing surgery. Total gastrectomy and esophagojejunostomy were performed on Sprague-Dawley rats to produce esophageal reflux of duodenal juice (n = 12). Three days before surgery they were randomized into three groups: animals which received tap water; animals which received acidified water at pH 1.8; and animals subjected to oral decontamination with triple antibiotics. During surgery and at autopsy after 2 weeks, intestinal juice was aspirated and analyzed immediately for bacterial content. The physiologic microflora of the rat jejunum contained Lactobacillus spp. and Bacteroides spp., both of which were resistant to the antibiotic regimen. Bacterial overgrowth with fecal bacteria was found following surgery. Acidified water did not alter the intestinal microflora. Triple antibiotics eliminated Escherichia coli and Proteus spp. and reduced the concentration of Enterococcus spp. Bacterial overgrowth by bacteria of the fecal flora occurs in the rat model of esophageal adenocarcinoma with the potential to catalyze the production of carcinogens.

Upregulation of ornithine decarboxylase mRNA expression in Barrett's esophagus and Barrett's-associated adenocarcinoma

The Barrett's multistage process is characterized histopathologically by progression from Barrett's intestinal metaplasia to Barrett's esophagus with dysplasia and ultimately adenocarcinoma. Understanding the cellular and molecular events in this multistage process may contribute to improved diagnosis and treatment. Ornithine decarboxylase (ODC) is the first enzyme in the biosynthesis of polyamines. Elevated ODC activity has been found to be associated with progression during Barrett's esophagus, but the regulation of ODC gene expression in the development of Barrett's-associated adenocarcinoma has not been reported. The aim of this study was to assess the prevalence and timing of ODC mRNA expression in the Barrett's metaplasia-dysplasia-adenocarcinoma sequence. ODC mRNA expression levels, relative to the stably expressed internal reference gene beta-actin, were measured using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method (ABI 7700 Sequence Detector System) in 104 specimens from 19 patients with Barrett's esophagus without carcinoma and 22 patients with Barrett's-associated adenocarcinoma. The median ODC mRNA expression levels were significantly increased in Barrett's esophagus tissues compared to matched normal tissues in patients without adenocarcinoma of the esophagus (P = 0.002; Wilcoxon test). A significant progressive increase in ODC mRNA expression was detectable through the stages of the metaplasia-dysplasia-carcinoma sequence in patients with Barrett's-associated adenocarcinoma (r = 0.719; P < or = 0.001; Spearman's rho test). These findings show that upregulation of ODC mRNA expression is an early event in the development and progression of Barrett's-associated adenocarcinoma of the esophagus, and they suggest that high ODC mRNA expression levels may be a clinically useful biomarker for the detection of occult adenocarcinoma

Retinoic acid receptor-alpha messenger RNA expression is increased and retinoic acid receptor-gamma expression is decreased in Barrett's intestinal metaplasia, dysplasia, adenocarcinoma sequence

BACKGROUND

Expression levels of the retinoic acid receptors (RAR-alpha, RAR-beta, and RAR-gamma) are significantly different in neoplastic tissues compared with non-neoplastic tissues for some tumors. This study investigated whether retinoic acid receptor messenger RNA (mRNA) expression levels are altered in Barrett's esophagus and Barrett's adenocarcinoma tissues.

METHODS

Relative mRNA expression levels of the RARs were quantified by using the ABI 7700 Sequence Detector (Taqman) system in Barrett's intestinal metaplasia (n = 15), dysplasia (n = 6), adenocarcinoma (n = 17), and matching normal esophagus tissues (n = 36).

RESULTS

RAR-alpha expression was significantly increased, and RAR-gamma expression was significantly decreased, at higher stages in the Barrett's sequence. There was almost complete loss of RAR-gamma expression (relative expression level < or = 1) in a majority (70%) of the dysplasia and adenocarcinoma tissues. There were significant differences in RAR-alpha and RAR-gamma expression in histopathologically normal tissues in patients with cancer versus patients without cancer. RAR-beta expression levels were significantly elevated in adenocarcinoma versus normal esophagus tissues. The RAR expression profile was similar for cancers arising within the esophagus and for cancers arising at the gastroesophageal junction.

CONCLUSIONS

RAR mRNA expression levels are significantly different in Barrett's tissues compared with normal esophagus tissues, and these levels are significantly different in Barrett's dysplasia and adenocarcinoma tissues compared with nondysplastic tissues. These results suggest that RAR mRNA levels may be useful biomarkers for this disease and that gastroesophageal junction adenocarcinomas are genetically similar to esophageal adenocarcinomas. These results also suggest that a cancer field is present in the esophagus in patients with cancer and that genetic alterations can precede histopathologic alterations in this disease.

Biomaterial properties and biocompatibility in cell culture of a novel self-inflating hydrogel tissue expander

The aim of this study was to investigate the swelling properties and the biocompatibility of a novel tissue expander material. The self-inflating material is a hydrogel consisting of a modified copolymer of methylmethacrylate and N-vinyl-2-pyrrolidone, which takes up water by osmosis. To increase the swelling volume, the primarily neutral gel material was modified by converting it into an ionized gel. To study the swelling and pressure behavior of the material, the anhydrous gel cylinders were equilibrated in distilled water, saline, and sugar solutions. The biocompatibility was investigated in cell culture. We tested the hydrogel eluate after swelling for cytotoxicity and mutagenicity using the cell lines MRC-5 and P3X63 Ag8 653 (Ag8). Furthermore, particles of the material were added to cell cultures to induce foreign body reactions and to verify its influence on monocyte differentiation. The material has a swelling capacity (Q = maximum swelling volume/anhydrous volume) of 5 to 50 depending on the degree of ionization of the polymer network. In this study, two polymer modifications with a swelling equilibrium of Q = 11.1 and 30 in water were tested. The swelling ratio also depends on concentration and ion content of the equilibration medium. The highest swelling capacity was found in water, the lowest in Ringer's solution. The swelling of the anhydrous material with the swelling capacity of Q = 11.1 fits best the average purpose of material properties for tissue expansion and generates a maximal hydrostatic pressure of approximately 235 mmHg. Effects on cell proliferation were detected only at the highest eluate concentration tested (i.e., eluate: culture medium = 1:1), which was far beyond physiological values, whereas mutagenicity was absent. Monocytes neither migrated nor tightly attached to the hydrogel. They neither phagocytose the material nor did they show any sign of a foreign body reaction, e.g., formation of multinucleated giant cells or monocyte proliferation. In the presence of hydrogel material, the differentiation processes of monocytes to macrophages or dendritic cells, respectively, were found to be undisturbed. From these results, we conclude that there is a high biocompatibility of the expander material, which may be a favorable and interesting candidate for further clinical applications.

Fields of aberrant CpG island hypermethylation in Barrett's esophagus and associated adenocarcinoma

Esophageal adenocarcinoma (EAC) is thought to develop through a multistage process in which Barrett's metaplasia progresses through low- and high-grade dysplasia to invasive cancer. Transcriptional silencing of tumor suppressor genes by promoter CpG island hypermethylation has been observed in many types of human cancer. Analysis of CpG island hypermethylation in EAC has thus far been limited to the CDKN2A (p16) gene. In this study, we extend the methylation analysis of EAC to include three other genes, APC, CDH1 (E-cadherin), and ESR1 (ER, estrogen receptor alpha), in addition to CDKN2A. Molecular analysis can provide insight into the complex relationships between tissues with different histologies in Barrett's esophagus and associated adenocarcinoma. Therefore, we have mapped the spatial distribution of methylation patterns in six esophagectomy cases in detail. Hypermethylation of the four CpG islands was analyzed by the MethyLight technique in 107 biopsies derived from these six patients for a total of 428 methylation analyses. Our results show that normal esophageal squamous epithelium is unmethylated at all four CpG islands. CDH1 is unmethylated in most other tissue types as well. Hypermethylation of ESR1 is seen at high frequency in inflammatory reflux esophagitis and at all subsequent stages, whereas APC and CDKN2A hypermethylation is found in Barrett's metaplasia, dysplasia, and EAC. When it occurs, hypermethylation of APC, CDKN2A, and ESR1 is usually found in a large contiguous field, suggesting either a concerted methylation change associated with metaplasia or a clonal expansion of cells with abnormal hypermethylation.

Laparoscopic esophageal surgery

In its 9-year history, laparoscopic esophageal surgery has become second only to gallbladder surgery in the frequency of minimally invasive procedures performed in routine surgical practice. Laparoscopic fundoplication has assumed a central role in the surgical treatment of gastroesophageal reflux. Laparoscopic myotomy has emerged as the optimal form of therapy for achalasia, and staging laparoscopy has been identified as an important adjunct to the preoperative evaluation of esophageal and gastroesophageal junction carcinoma. Laparoscopic paraesophageal hernia repair and remedial laparoscopic antireflux surgery currently are gaining acceptance. Laparoscopic gastroplasty, esophagectomy, and diverticulectomy are undergoing clinical trials, and their roles remain to be defined.

Surgery, radiotherapy, and chemotherapy in carcinoma of the esophagus

Esophageal carcinoma remains a highly lethal disease that has shown a recent profound increase in prevalence and an equally dramatic epidemiologic shift. There is a well recognized causal association between gastroesophageal reflux disease and adenocarcinoma of the esophagus, and the molecular events underlying this progression from mucosal injury, to metaplasia, to dysplasia, to carcinoma are now becoming clear. Current diagnostic modalities and preoperative staging systems all have significant limitations. Fortunately, chemoprevention strategies and the identification of clinically useful molecular biomarkers that may be used to stage disease and select appropriate therapy are on the horizon. The extent of surgical resection for esophageal carcinoma remains an area of great controversy. Disease that is confined to the mucosa is being diagnosed more commonly, and endoscopic ablative techniques have been proposed. To date, however, preoperative discrimination of tumor depth and presence of regional nodal metastases remains inadequate in these very early lesions, and caution is urged before adopting therapies that may compromise cure. For disease penetrating the mucosa, the extent of surgical therapy must be tailored by the objectives of treatment (cure vs palliation) and preoperative stage. Surgical resection is the current standard of care, with combined-modality therapy reserved for prohibitive surgical candidates. No clear survival benefit has been documented for neoadjuvant radiotherapy or chemotherapy alone. The results of preoperative combined-modality therapy, including three prospective, randomized trials, are encouraging but to date have not shown a definite benefit.

Minimally invasive approaches to antireflux surgery

Gastroesophageal reflux disease is one of the most common disorders affecting western civilization. Historically, surgical antireflux therapy was reserved for patients who had failed medical therapy, typically in the presence of refractory ulcers or difficult-to-manage strictures. More recently, with improvements in acid control, these acid-pepsin-related complications of reflux have been replaced by the malignant complications of reflux disease, with emphasis now on total control of reflux. Recent developments in surgical technique and the demonstrated effectiveness of a variety of minimally invasive treatment options have changed our approach to these patients. This article summarizes the recommended diagnostic evaluation of patients with reflux symptoms and the current indications for antireflux surgery. The techniques of commonly performed minimally invasive antireflux procedures are described along with a review of the results to be expected. Future prospects for improving the management of reflux are discussed; these include recently described nonsurgical methods for restoring competency to the lower esophageal sphincter.

Is adenocarcinoma following esophagoduodenostomy without carcinogen in the rat reflux-induced?

BACKGROUND

A widely used rat model for reflux-induced esophageal adenocarcinoma in the absence of carcinogens involves induction of duodenoesophageal reflux by performance of esophagoduodenostomy. The aim of this study was to test the hypothesis that acid reflux reduces the incidence of adenocarcinoma in this animal model.

METHODS

One hundred ninety 8-week-old male Sprague-Dawley rats were studied. The animals were randomly divided into four groups with a different type of reflux established in each group. Group 1 had an esophagoduodenostomy for duodenogastroesophageal reflux (n = 59), group 2 had an esophagoduodenostomy and a total gastrectomy for duodenoesophageal reflux (n = 54), group 3 had an esophagoduodenostomy and a total gastrectomy with acid supplementation with acidified water to control for the effect of the gastrectomy (n = 50), and group 4 had a total gastrectomy with Roux-en-Y reconstruction to eliminate all reflux (n = 25). One hundred eighty-eight surviving animals were sacrificed at 36 weeks of age and the resected esophagi were examined.

RESULTS

All animals except the no reflux control group had severe reflux esophagitis. The frequency of tumor development was similar in all study groups. All of the tumors were well-differentiated adenocarcinomas that were located on the external surface of the bowel either at or immediately distal to the esophagoenteric anastomosis. The tumors appeared to arise from the submucosa and did not involve the overlying mucosa. There was no definite evidence of columnar lining of the esophagus but an admixture of squamous and columnar epithelium was found microscopically in all groups. This finding was unrelated to the presence and composition of reflux.

CONCLUSIONS

Adenocarcinomas in this animal model are not reflux-induced and do not arise from the mucosa. Despite previous reports to the contrary, we suggest that this model may not be valid for the study of reflux-induced esophageal adenocarcinoma.

Determinants of intestinal metaplasia within the columnar-lined esophagus

HYPOTHESIS

The clinical and physiological features of patients with short segments of columnar-lined esophagus (CLE) with and without intestinal metaplasia (IM) are distinct.

DESIGN

Retrospective case series.

SETTING

University tertiary referral center.

PATIENTS

Sixty-five consecutive patients with a 2-cm or shorter length of endoscopically visible CLE.

INTERVENTIONS

The type of CLE and the presence of Helicobacter pylori were determined by histopathologic examination of esophageal and gastric antrum biopsy specimens. All patients underwent esophageal manometry and simultaneous 24-hour pH and bilirubin monitoring.

MAIN OUTCOME MEASURES

Clinical and physiological data were compared in patients with and without IM.

RESULTS

Thirty-six patients had IM and 29 had cardiac-type mucosa without IM in biopsy specimens from the CLE. There was no significant difference in age or sex distribution, but the duration of symptoms was significantly longer in patients with IM (10 vs 5 years; P = .03). Abnormal esophageal acid exposure was found in 30 (83%) of 36 patients with IM and 23 (79%) of 29 patients without IM. The prevalence of abnormal bilirubin exposure was significantly higher in patients with IM (75% [27/36]) than in those without IM (41% [12/29]; P = .01). There was no significant difference in the prevalence of H pylori infection between the 2 groups (8% vs 10%; P >.99).

CONCLUSIONS

Patients with short segments of CLE and IM have similar esophageal acid exposure but significantly higher frequency of abnormal bilirubin exposure and longer median duration of reflux symptoms than patients without IM. Therefore, CLE, regardless of histological type, is a manifestation of gastroesophageal reflux disease. The presence of duodenoesophageal reflux and the duration of reflux seem to be important in the pathogenesis of IM.

Laparoscopic repair of large type III hiatal hernia: objective followup reveals high recurrence rate

BACKGROUND

Recent studies based on symptomatic outcomes analyses have shown that laparoscopic repair of large type III hiatal hernias is safe, successful, and equivalent to open repair. These outcomes analyses were based on a relatively short followup period and lack objective confirmation that the hernia has not recurred. The aim of this study was to compare the outcomes of laparoscopic and open repair of large type III hiatal hernia using both symptomatic evaluation and barium study to assess the integrity of the repair.

STUDY DESIGN

Fifty-four patients underwent repair of a large type III hiatal hernia between 1985 and 1998. The surgical approach was laparotomy in 13, thoracotomy in 14, and laparoscopy in 27. An antireflux procedure was included in all patients. Symptomatic outcomes were assessed using a structured questionnaire at a median of 24 months and was complete in 51 of 54 patients (94%). A single radiologist, without knowledge of the operative procedure, assessed the integrity of the repair using video esophagram. Videos were performed at a median of 27 months (35 months open and 17 laparoscopic) and were completed in 41 of 54 patients (75%).

RESULTS

Symptomatic outcomes were similar in both groups with excellent or good outcomes in 76% of the patients after laparoscopic repair and 88% after an open repair. Reherniation was present in 12 patients and was asymptomatic in 7. A recurrent hernia was present in 12 of the 41 patients (29%) who returned for a followup video esophagram. Forty-two percent (9 of 21) of the laparoscopic group had a recurrent hernia compared with 15% (3 of 20) of the open group (p < 0.001 log-rank value on recurrence-free followup).

CONCLUSIONS

Laparoscopic repair of type III hiatal hernias is associated with a disturbingly high (42%) prevalence of recurrent hernia. More than half such recurrences have few, if any, symptoms.

Alkaline phosphatase expression during monocyte differentiation. Overlapping markers as a link between monocytic cells, dendritic cells, osteoclasts and osteoblasts

Human monocytes (Mo) in culture can be differentiated into macrophages (M phi), dendritic cells (DC) and osteoclasts. In addition, we have established a Mo-derived in vitro granuloma model which here was compared with ex-vivo isolated foreign body granuloma cells. In these models overlapping phenotypes developed between monocyte-derived dendritic cells (MoDC), osteoclasts, M phi, and osteoblasts. In Mo cultures granulomas were induced by immobilized particulate material. AP activity (osteoblast marker) was found to be co-expressed with cytoplasmic tartrate resistant acid phosphatase (TRAP) as a marker of osteoclasts. While proliferating, the number of AP+ cells decreased, being replaced by cells co-expressing the osteoclast markers vitronectin receptor (VNR) and TRAP. Coexpression of the Mo/M phi marker CD68 with AP or VNR confirmed the monocytic origin of the cells. When Mo were treated with interleukin-4 (IL-4), the number of AP+ cells markedly increased and remained stably expressed over 12 days. In explants from ex vivo granulomas obtained from endoprosthetic revisions the major cell type was the AP+ cell co-expressing CD68. The bone-specific alkaline phosphatase (BAP) as a marker of osteoblasts was detected by FACS analysis in the ex vivo granuloma cells. By RT-PCR the mRNA for osteocalcin, which is a highly specific marker for osteoblasts, was detected. From our results we conclude an ontogenetic relationship between macrophages, DC and osteoclasts. Furthermore, the data suggest a transdifferentiation between Mo and osteoblasts.

Feasibility of planar myocardial carbon 11-acetate imaging

BACKGROUND

Myocardial oxygen consumption can be determined by using carbon 11-acetate (11C-acetate) and positron emission tomography (PET). The aim of this study was to validate planar 11C-acetate scintigraphy in healthy individuals by relating the myocardial clearance rate of dynamic 11C-acetate scintigraphy with the rate-pressure product, which is used as a measure of cardiac work. Also, the optimal curve-fitting procedure of the time-activity curve and the intraobserver and interobserver variation of determining the clearance rates were assessed.

METHODS AND RESULTS

Six subjects were studied at rest, and seven subjects were studied during dobutamine stimulation. Imaging was performed with a planar camera equipped with high-energy collimators for 45 minutes after the injection of 185 MBq of 11C-acetate. Myocardial time-activity curves were corrected for decay. During the study, heart rates and blood pressures were measured to calculate the rate-pressure product. Myocardial time-activity curves showed a clear biphasic pattern. Clearance rates were expressed in k values. The best fitting procedure, as assessed by means of the lowest error of k and the best correlation with the rate-pressure product, proved to be a monoexponential fit on the first part of the time-activity curve (kmono). Subjects studied during dobutamine infusion had significantly higher rate-pressure product (15.0 +/- 2.1*10(3) vs 8.6 +/- 1.2*10(3), P < .001) and 11C-acetate clearance rates (kmono = 0.0657 +/- 0.0110 vs 0.0313 +/- 0.0056, P < .0001) than subjects studied at rest. There was low intraobserver and interobserver variation in determining kmono values. A significant correlation between the rate-pressure product and the monoexponential clearance rate was found (kmono = 5.11*10(-6)*RPP-0.012; r = 0.94, P < .001).

CONCLUSIONS

The estimation of myocardial oxygen consumption is feasible with planar 11C-acetate scintigraphy. Clearance rates and the relation with the rate-pressure product are similar to those reported in PET studies. This technique may be used for the assessment and follow-up of global myocardial metabolic abnormalities, eg, in patients with hypertensive heart disease, cardiomyopathy, myocarditis, and valvular disease.

Telomerase reverse transcriptase expression is increased early in the Barrett's metaplasia, dysplasia, adenocarcinoma sequence

Barrett's esophagus is a multistage polyclonal disease that is associated with the development of adenocarcinoma of the esophagus and esophagogastric junction. Telomerase activation is associated with cellular immortality and carcinogenesis, and increased expression of the telomerase reverse transcriptase catalytic subunit (hTERT) has been used for the early detection of malignant diseases. To identify biomarkers associated with each stage of the Barrett's process, relative mRNA expression levels of hTERT were measured using a quantitative reverse transcription-polymerase chain reaction method (ABI 7700 Sequence Detector (TaqMan system) in Barrett's intestinal metaplasia (n = 14), Barrett's dysplasia (n = 10), Barrett's adenocarcinoma (n = 14), and matching normal squamous esophagus tissues (n = 32). hTERT expression was significantly increased at all stages of Barrett's esophagus, including the intestinal metaplasia stage, compared to normal tissues from patients without cancer (intestinal metaplasia vs. normal esophagus, P <0.0001; dysplasia, P = 0.001; adenocarcinoma, P = 0.007; all Mann-Whitney U test ). hTERT expression levels were significantly higher in adenocarcinoma tissues than in intestinal metaplasia tissues (P = 0.003), and were higher in dysplasia compared with intestinal metaplasia tissues (P = 0.056). hTERT levels were also significantly higher in histologically normal squamous esophagus tissues from cancer patients than in normal esophagus tissues from patients with no cancer (P = 0.013). Very high expression levels ([hTERT x 100: beta-actin] >20) were found only in patients with cancer. These findings suggest that telomerase activation is an important early event in the development of Barrett's esophagus and esophageal adenocarcinoma, that very high telomerase levels may be a clinically useful biomarker for the detection of occult adenocarcinoma, and that a widespread cancer "field" effect is present in the esophagus of patients with Barrett's cancer.

Definition of histopathologic changes in gastroesophageal reflux disease

A series of 71 patients with multiple measured biopsies of the gastroesophageal junctional region permitting assessment of the presence and length of different glandular epithelial types is presented. All but nine of 53 patients in whom a 24-hour pH study was performed had abnormal reflux, suggesting that endoscopic recognition of an abnormal columnar mucosa at the gastroesophageal junction sufficient to precipitate multiple-level biopsies indicates a high probability of abnormal reflux. All patients had cardiac mucosa (CM) or oxyntocardiac mucosa (OCM). CM was present in 68 of 71 patients. The prevalence of intestinal metaplasia increased with increasing CM+OCM length, and was present in all 22 patients with a CM+OCM length >2 cm and in 20 of 49 patients with a CM+OCM length <2 cm. Patients with a CM+OCM length >2 cm had a markedly higher acid exposure than patients with a CM+OCM length <2 cm. The findings suggest that the presence of CM and OCM in the junctional region are predictive of abnormal acid exposure, and that increasing OCM+CM length correlates strongly with the amount of acid exposure. The histologic finding of CM and OCM represents a sensitive histologic criterion for gastroesophageal reflux rather than normal epithelia. These diagnostic criteria represent the first useful histologic definitions for assessing the presence and severity of reflux.

Gastroesophageal reflux disease in asthma: effects of medical and surgical antireflux therapy on asthma control

OBJECTIVE

To critique the English-language reports describing the effects of medical and surgical antireflux therapy on respiratory symptoms and function in patients with asthma.

METHODS

The Medline computerized database (1959-1999) was searched, and all publications relating to both asthma and gastroesophageal reflux disease were retrieved.

RESULTS

Seven of nine trials of histamine-receptor antagonists showed a treatment-related improvement in asthma symptoms, with half of the patients benefiting. Only one study identified a beneficial effect on objective measures of pulmonary function. Three of six trials of proton pump inhibitors documented improvement in asthma symptoms with treatment; benefit was seen in 25% of patients. Half of the studies reported improvement in pulmonary function, but the effect occurred in fewer than 15% of patients. In the one study that used optimal antisecretory therapy, asthma symptoms were improved in 67% of patients and pulmonary function was improved in 20%. Combined data from 5 pediatric and 14 adult studies of anti-reflux surgery indicated that almost 90% of children and 70% of adults had improvement in respiratory symptoms, with approximately one third experiencing improvements in objective measures of pulmonary function.

CONCLUSIONS

Fundoplication has been consistently shown to ameliorate reflux-induced asthma; results are superior to the published results of antisecretory therapy. Optimal medical therapy may offer similar results, but large studies providing support for this assertion are lacking.

Clinical significance of p53 mutations in adenocarcinoma of the esophagus and cardia

OBJECTIVE

To compare the frequency and spectrum of p53 gene mutations in adenocarcinomas of the esophagus and cardia and to compare clinical and pathologic features in patients with p53 mutant and nonmutant cancers.

SUMMARY BACKGROUND DATA

The p53 gene is commonly mutated in human cancers, and a p53 mutation is reported to be present in more than 50% of esophageal adenocarcinomas. Although many studies have investigated the frequency of p53 protein overexpression in adenocarcinomas of the esophagus or esophagogastric junction, few studies have assessed the frequency and clinical significance of p53 mutations in these tumors. In particular, the prognostic importance of p53 mutation is uncertain. Adenocarcinomas of the esophagus and cardia share many epidemiologic and pathologic features, but it is controversial whether they represent the same tumor. A comparison of the frequency and spectrum of mutations in adenocarcinomas of the esophagus and cardia would test whether these tumors are also similar at the molecular level.

METHODS

DNA was isolated from microdissected paraffin-embedded tumor tissues of patients who underwent esophagogastrectomy for adenocarcinoma of the esophagus (n = 19), cardia (esophagogastric junction, n = 12), or subcardia (n = 6). Exons 5 to 8 of the p53 gene were analyzed for the presence of mutations using the polymerase chain reaction with single-strand conformation polymorphism and DNA sequencing of bands showing abnormal mobility. The presence of mutation was confirmed by selective hybridization of a mutant-specific oligonucleotide to DNA isolated from the tumor.

RESULTS

p53 mutations were identified in 18 of 37 (48.6%) tumors. Patients with p53 mutant tumors were significantly younger and had a significantly poorer prognosis. There was a similar prevalence of p53 mutations in adenocarcinomas of the esophagus (53%) and cardia (58%). In contrast, mutations were relatively uncommon in subcardia adenocarcinomas (one mutant tumor [17%]). The types of mutations found in the esophageal and the cardia cancers were also similar.

CONCLUSIONS

Adenocarcinomas of the esophagus and cardia have a similar frequency and spectrum of p53 gene mutations, suggesting that these tumors have a common pathogenesis. Patients with mutations are younger, have signs of more advanced disease, and have a poorer prognosis than patients without mutations.

Suppression of gastric acid secretion in patients with gastroesophageal reflux disease results in gastric bacterial overgrowth and deconjugation of bile acids

The aim of this study was to test the hypothesis that gastric bacterial overgrowth is a side effect of acid suppression therapy in patients with gastroesophageal reflux disease (GERD) and that the bacteria-contaminated gastric milieu is responsible for an increased amount of deconjugated bile acids. Thirty patients with GERD who were treated with 40 mg of omeprazole for at least 3 months and 10 patients with GERD who were off medication for at least 2 weeks were studied. At the time of upper endoscopy, 10 ml of gastric fluid was aspirated and analyzed for bacterial growth and bile acids. Bacterial overgrowth was defined by the presence of more than 1000 bacteria/ml. Bile acids were quantified via high-performance liquid chromatography. Eleven of the 30 patients taking omeprazole had bacterial overgrowth compared to one of the 10 control patients. The median pH in the bacteria-positive patients was 5.3 compared to 2.6 in those who were free of bacteria and 3.5 in the control patients who were off medication. Bacterial overgrowth only occurred when the pH was >3.8. The ratio of conjugated to unconjugated bile acids changed from 4:1 in the patients without bacterial overgrowth to 1:3 in those with bacterial growth greater than 1000/ml. Proton pump inhibitor therapy in patients with GERD results in a high prevalence of gastric bacterial overgrowth. The presence of bacterial overgrowth markedly increases the concentration of unconjugated bile acids. These findings may have implications in the pathophysiology of gastroesophageal mucosal injury.

Current state, techniques, and results of laparoscopic antireflux surgery

The introduction of laparoscopic fundoplication has dramatically changed the face of antireflux surgery. Central to the success of laparoscopic fundoplication is careful preoperative patient evaluation and attention to surgical technique. Emerging evidence has questioned the long-term durability of laparoscopic partial fundoplications underscoring the place of laparoscopic Nissen fundoplication as the procedure of choice for most patients. The technique of laparoscopic Nissen fundoplication should incorporate crural closure, complete fundic mobilization by short gastric vessel division, and the creation of a short, loose fundoplication by enveloping the anterior and posterior fundic walls around the esophagus. Relief of typical reflux symptoms can be anticipated in over 90% of patients. The outcome of atypical reflux symptoms is less predictable, on average two thirds of patients benefiting. The cost of laparoscopic fundoplication compares favorably to long-term medical therapy and open fundoplication. Current trends indicate that laparoscopic fundoplication is being used increasingly as an alternative to long-term medical therapy.

Endoscopic grading of the gastroesophageal valve in patients with symptoms of gastroesophageal reflux disease (GERD)

BACKGROUND

It has been suggested that endoscopic grading of the gastroesophageal flap valve is a good predictor of the reflux status.

METHODS

To test this hypothesis, 268 symptomatic patients underwent endoscopic grading of the gastroesophageal valve using Hill's classification, with grades I through IV. Esophageal acid exposure, lower esophageal sphincter characteristics, and the degree of esophageal mucosal injury were compared among the groups.

RESULTS

The prevalence of a mechanically defective sphincter, abnormal esophageal acid exposure, erosive esophagitis, and Barrett's esophagus increased with increasing alteration of the gastroesophageal valve. The presence of a grade IV valve indicated increased esophageal acid exposure in 75% of patients. As a predictor, this is similar to lower esophageal sphincter pressure but not as good as the presence of esophageal mucosal injury.

CONCLUSIONS

Endoscopic grading of the gastroesophageal valve provides useful information about the reflux status but is less useful as an indicator of gastroesophageal reflux disease (GERD) than the presence of esophageal mucosal injury.

Abnormal esophageal body function: radiographic-manometric correlation

Stationary manometry is the gold standard for the evaluation of patients with suspected esophageal motility disorders. Comparison of videoesophagram in the evaluation of esophageal motility disorders with stationary motility has not been objectively studied. Two hundred two patients with foregut symptoms underwent stationary motility and videoesophagram. Radiographic assessment of esophageal motility was done by video recording of five 10-cc swallows of barium. Abnormal esophageal body function was defined by stasis of barium in the middle third of the esophagus on at least four swallows or stasis on at least three swallows in the distal third. Stationary manometry was performed using a five-channel water perfused system. Contraction amplitudes <25 mm Hg in any of the last two channels or the presence of simultaneous or interrupted waves in 10 per cent or more were considered to be abnormal. Sixty-two patients had abnormal manometry. Thirty-four patients also demonstrated abnormal videoesophagrams for an overall sensitivity of 55 per cent. The positive predictive value was 53 per cent; specificity was 79 per cent; and negative predictive value was 80 per cent. Sensitivity was greatest in patients with achalasia (94%) and scleroderma (100%) and in patients presenting with dysphagia (89%). Sensitivity was poor for nonspecific esophageal motility disorders. A videoesophagram is relatively insensitive in detecting motility disorders. It seems most useful in the detection of patients with esophageal dysfunction, for which surgical treatment is beneficial, and in those patients presenting with dysphagia.