Barrett's esophagus in Latinos undergoing endoscopy for gastroesophageal reflux disease symptoms.

Previous studies comparing the prevalence of Barrett's esophagus in Latinos and non-Latino whites are inconsistent. The aim of the study is to compare the prevalence of Barrett's esophagus in Latinos and non-Latino whites and to determine risk factors associated with Barrett's esophagus. Between March 2005 and January 2009, consecutive Latino and non-Latino white patients who underwent endoscopy for primary indication for symptoms of gastroesophageal reflux disease were identified by examining the internal endoscopy database at Los Angeles County + USC Medical Center. Barrett's esophagus was defined by columnar-lined distal esophagus on endoscopy confirmed by intestinal metaplasia on histology. Clinical features and endoscopic findings were retrospectively reviewed. The mean age of the 663 patients was 50 ± 12 years, 30% were male, and 92% were Latino. Compared with non-Latino whites, Latinos had more females (72% vs. 46%; P = 0.0001) and more Helicobacter pylori infection (53% vs. 24%; P = 0.003) but less tobacco use (7% vs. 17%; P = 0.01). Overall, 10% (68/663) of all patients had Barrett's esophagus whereas the prevalence was 10% (62/611) among the Latinos and 12% (6/52) among the non-Latino whites (OR 0.9, 95% CI 0.4-2.1; P = 0.75). One patient in the Latino group had high-grade dysplasia. On multivariate analysis, male gender (AOR 2.3, 95% CI 1.4-4.1; P = 0.002), diabetes (AOR 2.2, 95% CI 1.1-4.5; P = 0.03), and age ≥55 years (AOR 2.2, 95% CI 1.3-3.8; P = 0.006) were independently associated with Barrett's esophagus; Latino ethnicity remained nonsignificant (AOR 1.1, 95% CI 0.4-2.7; P = 0.88). In Latinos undergoing endoscopy for gastroesophageal reflux disease symptoms, the prevalence of Barrett's esophagus was 10%, comparable with non-Latino white controls as well as the prevalence previously reported among Caucasians. In addition to established risk factors, diabetes was associated with Barrett's esophagus.

The gene expression profile of cardia intestinal metaplasia is similar to that of Barrett's esophagus, not gastric intestinal metaplasia.

The etiology and significance of cardia intestinal metaplasia (CIM) is disputed. CIM may represent a form of Barrett's esophagus due to reflux or could reflect generalized gastric intestinal metaplasia due to Helicobacter pylori. The aim of this study was to utilize gene expression data to compare CIM to Barrett's and gastric intestinal metaplasia. Endoscopic biopsies were classified by endoscopic and histologic criteria as CIM (n= 33), Barrett's (n= 25), or gastric intestinal metaplasia of the antrum or body (n= 18). The squamocolumnar and gastroesophageal junctions were aligned in CIM patients and patients with diffuse gastric intestinal metaplasia were excluded. H. pylori was tested for in the biopsies of all patients. After laser-capture microdissection, quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the mRNA expression of a panel of nine genes that has been shown to differentiate Barrett's from other foregut mucosa. Cluster analysis with linear discriminant analysis of the expression data was used to classify each sample into groups based solely on similarity of gene expression. Cluster analysis was performed for three groups (CIM vs. Barrett's vs. gastric intestinal metaplasia) and two groups (CIM + Barrett's vs. gastric intestinal metaplasia). There was no difference in H. pylori infection among groups (P= 0.66). Clustering into three groups resulted in frequent misclassification between CIM and Barrett's while misclassification of gastric intestinal metaplasia was uncommon. The CIM and Barrett's groups were then combined for two group clustering and linear discriminant analysis correctly predicted 95% of CIM and Barrett's samples and 83% of gastric intestinal metaplasia samples based on gene expression alone. In conclusion, the gene expression profiles of CIM and Barrett's esophagus were similar in 95% of biopsies and differed significantly from that of gastric intestinal metaplasia. The indistinguishable gene expression profile of CIM and BE suggests that they may share a common etiology in the majority of patients with a similar biology, and calls into question the perception that CIM is an innocuous process.

Is intestinal metaplasia a necessary precursor lesion for adenocarcinomas of the distal esophagus, gastroesophageal junction and gastric cardia?

Adenocarcinoma of the distal esophagus and gastroesophageal junction are believed to arise in Barrett's esophagus with intestinal metaplasia. Whether adenocarcinoma can arise in columnar lined esophagus without intestinal metaplasia is in doubt. Whether adenocarcinoma of the gastric cardia arises in intestinal metaplasia of the gastric cardia is also in doubt. We aim to evaluate the relationship of size and stage of adenocarcinoma of the distal esophagus, gastroesophageal junction and gastric cardia to intestinal metaplasia and other types of columnar epithelium. Seventy-four patients who had esophagogastrectomy for adenocarcinomas in this region were examined histologically to assess the frequency of residual intestinal metaplasia in the surrounding epithelium. Tumors without residual intestinal metaplasia were evaluated for the presence of other columnar epithelia and correlated with tumor size and stage. Cardiac mucosa was present around all tumors. Residual intestinal metaplasia was present in 48 (65%) tumors, including 33/38 (87%) distal esophageal, 10/25 (45%) junctional and 5/11 (45%) gastric cardia tumors. The prevalence of intestinal metaplasia was 100% in all tumors that were less than 1 cm in maximum diameter and all intramucosal tumors. The prevalence of residual intestinal metaplasia decreased with increasing tumor size and stage. These data strongly support the contention that adenocarcinomas of this region, including those in the gastric cardia, arise in intestinal metaplastic epithelium. The absence of residual intestinal metaplasia in larger tumors is the result of tumor overgrowing the intestinal metaplasia from which it arose.

Cdx-2 expression in squamous and metaplastic columnar epithelia of the esophagus.

The molecular pathogenesis of Barrett's esophagus is poorly understood. Evidence suggests that at a phenotypic level, the metaplastic process begins with the transformation of squamous epithelium in the distal esophagus to cardiac mucosa, which subsequently becomes intestinalized. The homeobox gene Cdx-2 has been shown to be an important transcriptional regulator of embryonic differentiation and maintenance of adult intestinal type epithelium. We hypothesized that Cdx-2 gene expression levels increase with the phenotypic transformation of normal squamous mucosa to the intestinalized columnar mucosa of Barrett's esophagus. Endoscopic biopsies were obtained at the gastroesophageal junction in patients with symptoms of gastroesophageal reflux disease and classified according to histology: normal squamous mucosa (n = 62), cardiac mucosa (n = 19), oxynto-cardiac mucosa (n = 14), and intestinal metaplasia (n = 15). Duodenal biopsies (n = 26) served as the columnar control. After laser capture microdissection and RNA isolation, gene expression levels of Cdx-2 were measured in each tissue type by quantitative reverse transcription polymerase chain reaction. Consistent with its known function, Cdx-2 gene expression levels were highest in duodenal mucosa and nearly absent in squamous epithelium. There was a stepwise increase in Cdx-2 gene expression from cardiac to Barrett's epithelium (P < 0.001). Expression levels of Cdx-2 in cardiac and oxynto-cardiac mucosa were 40-70 times higher and Barrett's mucosa 400 times higher than that found in squamous epithelium. Relative expression of the homeobox gene Cdx-2, known to induce differentiation of intestinal type epithelium, increases in a stepwise fashion during the phenotypic transformation of distal esophageal squamous mucosa to cardiac columnar mucosa and to the intestinalized columnar mucosa of Barrett's esophagus. Therefore, Cdx-2 may be a potential biomarker to detect the early transition to Barrett's esophagus.

Gland ducts and multilayered epithelium in mucosal biopsies from gastroesophageal-junction region are useful in characterizing esophageal location.

SUMMARY. There is controversy as to whether oxynto-cardiac mucosa (OCM), cardiac mucosa (CM) and intestinal metaplasia (IM) found in the gastroesophageal-junction region line the anatomic stomach, esophagus or both. A total of 785 retroflex biopsies taken at the endoscopic gastroesophageal junction in 244 patients were evaluated for the presence of gland ducts and multilayered epithelium which are two recognized markers of esophageal mucosa. Oxyntic mucosa was found in 287 biopsies, OCM in 283, CM in 158, IM in 30 and squamous epithelium in 53 (some biopsies had more than one epithelial type). Esophageal gland ducts and multilayered epithelium were absent in all biopsies with oxyntic mucosa. Sixty-four (13.6%) of 471 biopsies with OCM, CM and IM contained esophageal gland ducts, and 68 of 471 (14.4%) contained multilayered epithelium. Ninety-eight of 471 (20.8%) biopsies contained either gland ducts or multilayered epithelium. This study shows that 20.8% of biopsies at the gastroesophageal junction with OCM, CM and IM can be definitively characterized as lining the anatomic esophagus by the finding of gland ducts and multilayered epithelium. The absence of these markers in oxyntic mucosa confirms this epithelium as gastric. The presence of gland ducts and multilayered epithelium can be used by pathologists to objectively ascribe an esophageal or gastric location to a biopsy from the gastroesophageal junction.

Ki67 expression in different epithelial types in columnar lined oesophagus indicates varying levels of expanded and aberrant proliferative patterns.

AIMS: To evaluate proliferative patterns in metaplastic columnar epithelia of the oesophagus, classified as oxynto-cardiac (n = 43), cardiac (n = 45) intestinal without dysplasia (n = 41), dysplastic intestinal epithelium (n = 25), and adenocarcinoma (n = 15) by Ki67 immunohistochemistry. METHODS AND RESULTS: Abnormal patterns of Ki67 immunoreactivity were classified into (i) expanded proliferation, characterized by increased levels of Ki67 expression in the deep and mid third of the foveolar pit; and (ii) aberrant proliferation, characterized by positive staining in the surface epithelium and superficial third of the foveolar pit. A significant step-wise increase in the frequency of expanded proliferation was seen in oxynto-cardiac, cardiac, intestinal and dysplastic intestinal epithelium indicative of increasing levels of damage. Aberrant proliferation was absent in oxynto-cardiac mucosa, present at a low and similar level in cardiac, intestinal and low-grade dysplastic epithelia and at a significantly increased frequency in high-grade dysplasia. CONCLUSIONS: These findings suggest that oxynto-cardiac mucosa occurs in a low damage environment and intestinal metaplasia in a high damage environment along the length of the columnar lined oesophageal segment. Aberrant proliferative patterns with Ki67 staining are not useful in differentiating reactive epithelia from low-grade dysplasia, but may prove useful in the diagnosis of high-grade dysplasia.

Controversies of the cardiac mucosa and Barrett's oesophagus.

Confusion regarding the diagnosis of Barrett's oesophagus exists because of a false dogma that cardiac mucosa is normally present in the gastro-oesophageal junctional region. Recent data indicate that the only normal epithelia in the oesophagus and proximal stomach are squamous epithelium and gastric oxyntic mucosa. When this fact is recognized, it becomes easy to develop precise histological definitions for the normal state (presence of only squamous and oxyntic mucosa), metaplastic oesophageal columnar epithelium (cardiac mucosa with and without intestinal metaplasia, and oxynto-cardiac mucosa), the gastro-oesophageal junction (the proximal limit of gastric oxyntic mucosa), the oesophagus (that part of the foregut lined by squamous and metaplastic columnar epithelium), reflux disease (the presence of metaplastic columnar epithelium), and Barrett's oesophagus (cardiac mucosa with intestinal metaplasia). It is also possible to assess accurately the severity of reflux which is directly proportional to the amount of metaplastic columnar epithelium, and the risk of adenocarcinoma which is related to the amount of dysplasia in intestinal metaplastic epithelium present within the columnar lined segment of the oesophagus. Histopathological precision cannot be matched by any other modality and can convert the confusion that exists regarding diagnosis of Barrett's oesophagus to complete lucidity in a manner that is simple, accurate, and reproducible.

Distribution and significance of epithelial types in columnar-lined esophagus.

An abnormal columnar-lined esophagus (CLE) is characterized by the presence of cardiac mucosa (CM) oxynto-cardiac mucosa (OCM), and intestinal metaplastic epithelium (IM) between gastric oxyntic mucosa and esophageal squamous epithelium. Thirty-two patients with CLE measuring 2-16 cm long had 5-37 biopsies per patient that showed CM, OCM, or IM for a total of 424 biopsies. Detailed mapping of the distribution of epithelial types within the CLE showed a distinct zonation of epithelial types; CM was present throughout the CLE, whereas OCM and IM tended to occur in the distal and proximal part of the CLE, respectively. All 32 patients (64 of 68 biopsies) showed IM at the most proximal level, compared with 22 of 32 patients (40 of 102 biopsies) in the most distal level biopsies. The density of goblet cells was highest in the most proximal level. The differences in prevalence and density of goblet cells between most proximal and most distal level biopsies were highly significant. These data suggest that for a given number of biopsies within the CLE, the likelihood of finding IM is greatest when the biopsies are concentrated in the most proximal area of the CLE. We suggest that glandular transformation of squamous epithelium results in CM. which evolves into OCM and IM by development of specialized parietal cells and goblet cells, respectively. The severity and nature of reflux cause these epithelial transformations in a constant and predictable manner. Recognition of these changes permits the development of morphologic definitions of reflux disease and the characterization of the sequence of epithelial changes that represent the reflux-adenocarcinoma sequence.

Curative resection for esophageal adenocarcinoma: analysis of 100 en bloc esophagectomies.

OBJECTIVE: To document what can be accomplished with surgical resection done according to the classical principles of surgical oncology. METHODS: One hundred consecutive patients underwent en bloc esophagectomy for esophageal adenocarcinoma. No patient received pre- or postoperative chemotherapy or radiation therapy. Tumor depth and number and location of involved lymph nodes were recorded. A lymph node ratio was calculated by dividing the number of involved nodes by the total number removed. Follow-up was complete in all patients. The median follow-up of surviving patients was 40 months, with 23 patients surviving 5 years or more. RESULTS: The overall actuarial survival rate at 5 years was 52%. Survival rates by American Joint Commission on Cancer (AJCC) stage were stage 1 (n = 26), 94%; stage 2a (n = 11), 65%; stage 2b (n = 13), 65%; stage 3 (n = 32), 23%; and stage 4 (n = 18), 27%. Sixteen tumors were confined to the mucosa, 16 to the submucosa, and 13 to the muscularis propria, and 55 were transmural. Tumor depth and the number and ratio of involved nodes were predictors of survival. Metastases to celiac (n = 16) or other distant node sites (n = 26) were not associated with decreased survival. Local recurrence was seen in only one patient. Latent nodal recurrence outside the surgical field occurred in 9 patients and systemic metastases in 31. Tumor depth, the number of involved nodes, and the lymph node ratio were important predictors of systemic recurrence. The surgical death rate was 6%. CONCLUSION: Long-term survival from adenocarcinoma of the esophagus can be achieved in more than half the patients who undergo en bloc resection. One third of patients with lymph node involvement survived 5 years. Local control is excellent after en bloc resection. The extent of disease associated with tumors confined to the mucosa and submucosa provides justification for more limited and less morbid resections.

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.

Carditis: a manifestation of gastroesophageal reflux disease.

This series consists of 141 patients in whom cardiac mucosa (CM) was present in biopsy samples from the gastroesophageal junctional region. Inflammation of CM, irrespective of its exact anatomic location, was defined as carditis and classified as acute or chronic based on the number of inflammatory cells present. In all cases, CM showed significant chronic inflammation. One hundred and eleven (79%) of the 141 patients with carditis showed no evidence of gastritis in biopsy samples from the gastric antrum and body. Helicobacter pylori was present in 20 of 141 (14%) patients; of these, 17 had evidence of a pangastritis, with 15 of these patients also showing H. pylori in CM. Patients with severe chronic inflammation in CM had a significantly higher acid exposure of the lower esophagus as quantitated by a 24-hour pH test than those with mild chronic inflammation in CM. Acute inflammation was uncommon in CM; it was present in only 26 of 141 (18.4%) patients. There was no significant difference in acid exposure of the lower esophagus between patients with and without acute inflammation in CM. The presence of acute inflammation in CM was significantly associated with distal gastritis and H. pylori infection. Men with carditis had quantitatively higher acid exposure of the lower esophagus than did women with this disorder. This difference was greatest in men with severe inflammation in CM who had no evidence of distal gastritis. These findings provide evidence that chronic inflammation in CM is strongly associated with acid reflux and that H. pylori is not a significant etiologic factor in carditis. They also show that in patients with CM in whom H. pylori gastritis develops, the infection frequently spreads to involve CM, resulting in acute inflammation with neutrophils that is superimposed on the chronic inflammation already present.

Laparoscopic ultrasonic epithelial ablation of the lower esophagus after nissen fundoplication in a porcine model: assessment of tissue damage and healing process.

A substantial population of patients with Barrett's esophagus has undergone antireflux surgery but still requires annual surveillance endoscopy. These patients would benefit from a definitive ablation of the Barrett's mucosa, which would remove the malignant potential of this disease. This study evaluates the efficacy of applying ultrasonic energy to remove the epithelium of the lower esophagus in a porcine model with prior Nissen fundoplication. Four Yakutan minipigs underwent laparoscopic Nissen fundoplication. After 2 weeks they underwent transgastric Cavitron ultrasonic surgical aspirator (CUSA; Valleylab, Boulder, CO) ablation of the lower esophageal epithelium. Healing of the mucosa was assessed by endoscopy at 2 weeks and pathological examination at 4 weeks after ablation. All pigs underwent successful laparoscopic Nissen fundoplication. Complete lower esophageal epithelial ablation was accomplished through the fundoplication in three animals. One pig developed a bezoar that prohibited ablation. At 2 weeks endoscopy showed patchy squamous epithelial regeneration, which was confirmed histologically. Esophageal specimens at 4 weeks showed complete regeneration of squamous epithelium with a partially healed small ulcer in one animal. No stricture formation was seen. We conclude that the CUSA technique can completely ablate Barrett's mucosa in the setting of a prior antireflux procedure. Healing with squamous mucosal regeneration is rapid and complete.

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.

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.

Histology of the gastroesophageal junction: an autopsy study.

Current diagnostic criteria for reflux disease and Barrett's esophagus are based on the belief that the gastroesophageal junction normally contains 2 cm of cardiac mucosa composed of mucous glands devoid of parietal cells. This autopsy study disproves this belief. Even when the entire circumference of the gastroesophageal junction is examined, pure cardiac mucosa was completely absent in 56% of patients. All patients had oxyntocardiac mucosa, in which glands contained a mixture of mucous and parietal cells. Cardiac and oxyntocardiac mucosae were present only in part of the circumference of the junction in 50% of patients. The measured maximum length of cardiac plus oxyntocardiac mucosa was less than 0.5 cm in 76% of patients. There was a tendency for the presence and extent of cardiac mucosa to increase with age. Cardiac mucosa at the junction is therefore frequently absent, has considerable individual variation, is very small in extent when present, is commonly absent from some part of the circumference of the junction, and increases in prevalence and length with age. These characteristics of cardiac mucosa make it highly unlikely that it is a normal structure. We develop the hypothesis that cardiac mucosa represents an early histologic manifestation of gastroesophageal reflux.

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.

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.

Loss of function of Trp53, but not Apc, leads to the development of esophageal adenocarcinoma in mice with jejunoesophageal reflux.

INTRODUCTION: APC and TP53 are tumor suppressor genes known to be altered frequently in human esophageal adenocarcinoma (EAC), which arises as a complication of reflux disease. To determine the functional role of these genes in the development of EAC, we have created reflux in mice gene-targeted for either Trp53 or Apc. METHODS: Wild-type (WT), p53-knockout (Trp53-/-), or Apc-mutated (ApcMin/+) mice were generated in our breeding colony. Total gastrectomy with esophagojejunostomy was performed at 6 weeks of age, creating jejunoesophageal reflux. Unoperated control mice were maintained under identical conditions. Mice were sacrificed at 30 weeks of age. Histology of the esophagus and jejunal anastamosis or gastroesophageal junction was reviewed by a single pathologist blinded to the genotype of the animal. RESULTS: The esophagus was normal in all of the unoperated mice (6 ApcMin/+, 6 WT, and 6 Trp53-/-). All operated mice (6 ApcMin/+, 12 WT, and 4 Trp53-/-) had esophagitis, with squamous hyperplasia and early focal ulceration. Barrett's metaplasia was identified in 33% of the operated ApcMin/+ (2/6) and 25% of the Trp53-/- (1/4) mice, but not in the WT mice. Of 4 operated Trp53-/- mice, all developed severe dysplasia of the squamous epithelium and 2 (50%) had EAC on histology, although no gross tumors were seen. No severe dysplasia or carcinoma was identified in any of the ApcMin/+ or WT mice. CONCLUSIONS: Loss of either Trp53 or Apc leads to the development of columnar metaplasia, whereas loss of Trp53, but not Apc, leads to development of cancer in mice with jejunoesophageal reflux.