Allan P. Weston

Magnification chromoendoscopy for the detection of intestinal metaplasia and dysplasia in Barrett’s oesophagus

Background: The presence of intestinal metaplasia (IM) in the columnar lined distal oesophagus defines Barrett’s oesophagus with the risk of future malignant transformation. The distribution of both IM and dysplasia (low grade (LGD) and high grade (HGD)) within the columnar lined oesophagus is patchy and mosaic requiring random biopsies. Techniques that could help target areas of high yield within Barrett’s mucosa would be helpful. Aim: To study the utility of high magnification chromoendoscopy (MCE) in the detection of IM, LGD, and HGD in patients with Barrett’s oesophagus. Methods: Consecutive patients detected with columnar mucosa in the distal oesophagus were studied using an Olympus magnification endoscope (GIF-Q16OZ, 115×). The distal oesophagus was sprayed with indigo carmine solution and the oesophageal columnar mucosa patterns were noted under high magnification and targeted for biopsy. All biopsies were read by pathologists blinded to the endoscopic findings. Results: Eighty patients with suspected Barrett’s oesophagus (that is, columnar lined distal oesophagus) were studied: mean age 62.7 years (range 35–81). Mean length of columnar mucosa was 3.7 cm (range 0.5–17). Three types of mucosal patterns were noted within the columnar mucosa after spraying indigo carmine and using MCE: ridged/villous pattern, circular pattern, and irregular/distorted pattern. The yield of IM on target biopsies according to the patterns was: ridged/villous 57/62 (97%) and circular 2/12 (17%). Six patients had an irregular/distorted pattern and all had HGD on biopsy (6/6 (100%)). Eighteen patients had LGD on target biopsies; all had the ridged/villous pattern. All patients with long segment Barrett’s were identified using MCE whereas 23/28 patients (82%) with short segment Barrett’s had the ridged/villous pattern. Conclusions: MCE helps visually identify areas with IM and HGD having specific patterns but not patients with LGD (appear similar to IM). MCE may be a useful clinical tool for the increased detection of patients with IM as well as for surveillance of patients for the detection of HGD. If these preliminary results are validated, MCE would help identify high yield areas, potentially eliminating the need for random biopsies.

Relative risk of dysplasia for patients with intestinal metaplasia in the distal oesophagus and in the gastric cardia

BACKGROUND Biopsy specimens obtained from the gastro-oesophageal junction can reveal intestinal metaplasia in patients presenting for routine upper endoscopy. The site of biopsy may play a critical role in determining the dysplasia risk of a patient. AIMS To evaluate prospectively the dysplasia risk in patients with intestinal metaplasia of the distal oesophagus or within the gastric cardia. METHODS Patients with short segment Barretts oesophagus (SSBO) and cardia intestinal metaplasia (CIM) were followed prospectively. RESULTS 177 patients with SSBO were identified (mean age 62 years, range 38–82; 91% whites). Twenty prevalence cases of dysplasia in SSBO were detected: 17 low grade dysplasia (LGD), three high grade dysplasia (HGD). Seventy six patients with CIM were identified (mean age 67 years, range 37–81; 81% whites). A single prevalence case of LGD in CIM was detected. During follow up of 78 SSBO and 34 CIM patients, dysplasia developed in nine (seven LGD, two HGD) with SSBO and in one (LGD) with CIM. There were significant differences between the two groups with respect to age, ethnicity, dysplasia prevalence, and incidence. Time to dysplasia progression was significantly longer in CIM compared with SSBO patients. Of the five patients with SSBO and HGD, one developed adenocarcinoma of the oesophagus on follow up. No HGD or cancers have been detected over this time period in CIM patients. CONCLUSIONS The dysplasia risk is significantly greater in SSBO than in CIM patients, indicating two potentially different clinical processes. Future studies should separate SSBO from CIM in order to enhance the understanding of the pathophysiology and malignant potential of each entity.

The frequency of Barrett's esophagus in high-risk patients with chronic GERD.

BACKGROUNDnThe reported frequency of Barretts esophagus (BE) in patients with reflux symptoms varies from 5% to 15%. The exact frequency of long-segment BE (LSBE) (>3 cm) and short-segment BE (SSBE) (<3 cm) in patients with chronic symptoms of GERD is uncertain. The aim of this study was to determine the frequency of LSBE and SSBE in consecutive patients presenting for a first endoscopic evaluation with GERD as the indication.nnnMETHODSnConsecutive patients presenting to the endoscopy unit of a Veterans Affairs Medical Center for a first upper endoscopy with the indication of GERD were prospectively evaluated. Demographic information (gender, race, age), data on tobacco use and family history of esophageal disease, and body mass index (BMI) were recorded for all patients. Before endoscopy, all patients completed a validated GERD questionnaire. The diagnosis of BE was based on the presence of columnar-appearing mucosa in the distal esophagus, with confirmation by demonstration of intestinal metaplasia in biopsy specimens. All patients with erosive esophagitis on the initial endoscopy underwent a second endoscopy to document healing and to rule-out underlying BE. Patients with a history of BE, alarm symptoms (dysphagia, weight loss, anemia, evidence of GI bleeding), or prior endoscopy were excluded.nnnRESULTSnA total of 378 consecutive patients with GERD (94% men, 86% white; median age 56 years, range 27-93 years) were evaluated. A diagnosis of BE was made in 50 patients (13.2%). The median length of Barretts esophagus (BE) was 1.0 cm (range 0.5-15.0 cm). Of the patients with BE, 64% had short-segment BE (SSBE) (overall SSBE frequency 8.5%). The overall frequency of long-segment BE (LSBE) was 4.8%. A hiatal hernia was detected in 62% of the patients with BE. Of the 50 patients with BE (median age 62 years, range 29-81 years), 47 (94%) were men and 98% were white. Eighteen patients (36%) were using tobacco at the time of endoscopy; 23 (46%) were former users. The median body mass index (BMI) of patients with BE was 27.3 (overweight). There were no significant differences between patients with LSBE and SSBE with respect to age, gender, ethnicity, BMI, and GERD symptom duration.nnnCONCLUSIONSnThe frequency of BE in a high-risk patient group (chronic GERD, majority white men, age > 50 years) who sought medical attention is 13.2%, with the majority (64%) having SSBE. These data suggest that the frequency of BE in patients with GERD has not changed. The true prevalence of BE in the general population, including those who do not seek care, is undoubtedly lower, currently and historically. The majority of patients with BE are overweight and have a hiatal hernia. Demographic data for patients with LSBE and SSBE are similar, indicating that these are a continuum of the same process.

Detection of Barrett's esophagus after endoscopic healing of erosive esophagitis

BACKGROUND:The presence of erosive esophagitis (EE) in patients presenting for upper endoscopy may prevent the detection of underlying Barretts esophagus (BE) in the distal esophagus.AIM:To prospectively determine the proportion of patients detected with BE upon repeat endoscopy after healing of EE.METHODS:Patients with endoscopically confirmed EE without BE were treated with standard doses of acid suppression therapy and a repeat endoscopy was performed to assess the presence of BE. If columnar mucosa was visualized in the distal esophagus, targeted biopsies were obtained and all biopsies were evaluated for the presence of intestinal metaplasia. BE was defined as columnar mucosa in the distal esophagus with intestinal metaplasia on biopsy.RESULTS:A total of 172 patients with reflux symptoms were diagnosed with EE without BE on initial endoscopy. They were treated with standard doses of proton pump inhibitor therapy, and after a mean duration of 11 wk (range 8–16 wk), a repeat endoscopy was performed to confirm healing of EE and to document the presence of BE. On repeat endoscopy, EE was completely healed in 116 patients (67%), and of those, BE was suspected in 32 patients (i.e., columnar-lined distal esophagus) and was confirmed in 16 patients (13.8%). In the 56 patients with persistent EE on repeat endoscopy, columnar mucosa in areas of previously healed esophagitis was visualized in 8 and confirmed in 5 patients (8.9% of nonhealed cases). Overall, 21 (12%) patients were confirmed with BE on repeat endoscopy; all men, mean age 61 yr with a median BE length of 0.5 cm (range 0.5–5 cm, interquartile range 0.5 cm). The majority of these patients (N = 19) had short segment Barretts esophagus (SSBE) (i.e., length <3 cm).CONCLUSIONS:In patients with EE undergoing treatment with acid suppressive therapy, BE (mainly SSBE) is detected in approximately 12% of patients on repeat endoscopy. Patients with reflux symptoms undergoing endoscopy for the detection of BE (i.e., screening) should be treated with acid suppressive therapy prior to endoscopy to enhance the yield of BE. Alternatively, if the goal is to document BE and if EE is found at the initial endoscopy, then repeat endoscopy may be considered after acid suppressive therapy.

Incidence and management of esophageal stricture formation, ulcer bleeding, perforation, and massive hematoma formation from sclerotherapy versus band ligation

OBJECTIVES:The aim of this study was to compare the incidence and endoscopic management of esophageal stricture formation, significant ulcer bleeding, massive esophageal hematoma, and perforation resulting from endoscopic band ligation or sclerotherapy of esophageal varices.METHODS:Consecutive esophagogastroduodenoscopies in which band ligation or sclerotherapy was performed for acute or obliterative therapy were entered into a computerized endoscopy database during a 7-yr period. Patients were excluded if they died within 72 h of treatment session from complications unrelated to the procedure. Sclerotherapy was performed using a 25-gauge needle with 1.5% sodium tetradecyl sulfate and banding was primarily performed with a Wilson-Cook 6 or 10 shooter. Complications were assessed at scheduled endoscopy and outpatient clinic visits, review of quality assurance data tallied on a monthly basis, and patient records.RESULTS:Two hundred twenty-one cases of sclerotherapy were performed in 59 patients compared to 110 cases of band ligation in 52 patients. Five patients were excluded because of death within 72 h of the procedure. The incidence of complications from sclerotherapy:banding on a per patient basis included: esophageal stricture formation 25.6%:1.9%, ulcer bleed 25.4%:5.7%, esophageal perforation 2.2%:0%, and massive esophageal hematoma 1.6%:0%. A significant difference in complications between sclerotherapy and band ligation was noted for both stricture formation (p < 0.0005) and ulcer bleeding (p < 0.0001). The majority of ulcer bleeds required no therapeutic intervention, whereas stricture formation required multiple dilation sessions.CONCLUSIONS:Band ligation has a significantly lower incidence of stricture formation and ulcer bleeding compared to sclerotherapy. The majority of complications can be managed with endoscopic interventions.

Yield of intestinal metaplasia in patients with suspected short-segment Barrett's esophagus (SSBE) on repeat endoscopy.

Biopsies from short segments of columnar appearing mucosa in the distal esophagus often fail to reveal intestinal metaplasia (IM). The yield of IM on repeat upper endoscopy (EGD) and biopsy in these patients is not known. Our aim was to prospectively evaluate the yield of IM on repeat EGD in patients with suspected SSBE (negative for IM on first EGD). Forty-three patients with suspected SSBE underwent repeat EGD with biopsy. This included 42 men and 1 woman, mean age 53 years (range: 45–90) with a mean columnar mucosa length of 1.26 cm (range: 0.5–2.5). On repeat EGD, 10 of 43 patients (23.2%) had evidence of IM. There was no statistically significant difference between the patients with proven SSBE on repeat EGD compared to those with persistent negative IM with regards to age, ethnicity, length of columnar mucosa, GERD symptoms, and hiatal hernia size. In conclusion, more than 20% of patients with suspected SSBE have evidence of IM (ie, proven SSBE) on repeat EGD. Thus repeat EGD with biopsy may be warranted in patients with tongues of columnar mucosa in the distal esophagus but no IM on the first biopsy to confirm the diagnosis of SSBE.

Biphasic estrogen response on bovine adrenal medulla capillary endothelial cell adhesion, proliferation and tube formation

Abnormal angiogenesis underlies many pathological conditions and is critical for the growth and maintenance of various types of tumors, including hormone-dependent cancers. Since estrogens are potent carcinogens in humans and rodents, and are involved in regulating angiogenesis, this study was designed to examine the effect of estrogen on the behavior of an established bovine capillary endothelial cell line, a simple and physiologically relevant model of the capillary wall. The results demonstrate that 17β-estradiol (E2), at different conditions, exerts both stimulatory and inhibitory effects on endothelial cell adhesion, proliferation and tube formation in vitro. Utilizing a cellular attachment assay, chronic exposure to nanomolar concentrations of E2 (i.e. 1 and 10 nM) increased endothelial cell adhesion significantly compared to vehicle treated controls. Cellular adhesion was inhibited by micromolar concentrations of E2. Cell count, PCNA immunohistochemistry and Western blot analysis demonstrated enhanced cell proliferation at low E2 concentration in estrogen-deplete medium. Inhibition of cellular proliferation was observed in both estrogen-replete and deplete medium at higher E2 concentrations (i.e. 1 and 10 µM). Furthermore, in vitro tube formation increased up to 3.0 fold in the presence of 10 nM and higher E2 concentrations. The present observations indicate that in vitro regulation of capillary endothelial cell adhesion, proliferation and capillary tube formation by estrogen, are dose dependent.

Expression of Cdc2 and Cyclin B1 in Helicobacter pylori-Associated Gastric MALT and MALT Lymphoma: Relationship to Cell Death, Proliferation, and Transformation

Mucosa-associated lymphoid tissue (MALT) may accumulate within gastric mucosa as a result of long standing Helicobacter pylori infection, and this acquired MALT may eventually develop into low-grade B-cell MALT lymphoma. To determine the possible association of cell cycle regulatory proteins and apoptotic cell death in the transformation of H. pylori gastritis to MALT lymphoma, the extent of cell proliferation, cell viability, expression of Cdc2/Cdk1 and cyclin B in gastric mucosal from patients with H. pylori-positive chronic gastritis (n = 7), MALT (n = 12), or MALT lymphoma (n = 12) were undertaken. Control tissue was obtained from H. pylori- negative patients (n = 5). Proliferating cell nuclear antigen (PCNA), Cdc2, and cyclin B1 were examined in paraffin embedded tissue by immunohistochemistry, while the apoptotic index (AI) was determined using the TUNEL assay. H&E staining for histology and modified Giemsa staining for the detection of H. pylori was conducted simultaneously. When compared to chronic gastritis tissue, those with MALT or MALT lymphoma had an increase in PCNA labeling index of 3.3- and 2.7-fold, while that for Cdc2/Cdk1 increased 2.3- and 3.1-fold, respectively. cyclin B1 labeling was 1.9 and 3.0 fold, while the AI was 3.4- and 1.4-fold higher in MALT and MALT lymphoma tissue, respectively, in the same comparison. On the other hand, the AI index of MALT lymphoma was 2. 5-fold lower than that for MALT tissues. The labeling scores for Cdc2/Cdk1 and cyclin B1 were significantly higher in the germinal center when compared to the mantle and marginal zones of MALT tissues. Using chi(2) and Pearson/Spearmans rho correlation coefficient with regression analyses, there was an inverse correlation between the AI and Cdc2/Cdk1 or cyclin B1 in MALT and MALT lymphoma tissues. There was no correlation between AI and PCNA labeling in any of the tissues. These results suggest that Cdc2/Cdk1 and cyclin B1 expression may be actively associated in the modulation of cellular death by apoptosis, as well as cellular proliferation and transformation during the evolution of H. pylori-associated gastritis to MALT lymphoma. Subclassification of high labeling score (>/=40) for Cdc2/Cdk1 and cyclin B1 and low labeling index (<0.6) for apoptotic cells in H. pylori-associated MALT may help in identifying a population of patients with an increased risk of developing MALT lymphoma.

A Two-Step Enriched-Nested PCR Technique Enhances Sensitivity for Detection of Codon 12 K-ras Mutations in Pancreatic Adenocarcinoma

Mutations at codon 12 of the K-ras gene have been detected in pancreatic adenocarcinomas by a variety of techniques. A few of these techniques are very sensitive, identifying the mutations in 96–100% of cases. However, these sensitive techniques are labor intensive, utilizing multistep processing and radioactive material. Much simpler techniques, involving nonradioactive single-step polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) have been employed to detect K-ras mutations at codon 12 in pancreatic adenocarcinomas. However, the low sensitivity of these single-step PCR/RFLP techniques is unacceptable. A simple and nonradioactive PCR/RFLP-based method for detection of K-ras codon 12 mutations in formalin-fixed, paraffin-embedded tissue sections of pancreatic adenocarcinoma is described and compared to the traditional PCR technique. K-ras gene mutations at codon 12 were detected by a modified two-step enrich-nested PCR (EN-PCR)/RFLP method, and their existence was confirmed by direct DNA sequencing analysis of the product. When the two-step EN-PCR/RFLP technique was compared to the single-step PCR/RFLP method, K-ras codon 12 mutations were detected in 100% of pancreatic adenocarcinomas (15/15) with the EN-PCR/RFLP method, while half as many (9/15) were detected with the single-step PCR/RFLP method. This study demonstrates that the sensitivity of the simple two-step EN-PCR/RFLP technique is comparable to that of the more complex methods for detecting K-ras mutations at codon 12 in formalin-fixed, paraffin-embedded tissue sections of pancreatic adenocarcinoma and its sensitivity is superior to that of the single-step technique.

Development of Barrett's Esophagus Six Months after Total Gastrectomy

Barretts esophagus (BE) is an acquired disease of the esophagus, in which esophageal squamous epithelium is changed by injury from reflux to metaplastic intestinal type columnar epithelium. BE is the premalignant lesion of adenocarcinoma of the esophagus. It is widely accepted that the long-standing reflux of gastric acid is a catalyst for the development of BE. More recent work points toward the reflux of duodenal secretions as a catalyst in this disease process as well. Moreover, the time course for the development of BE once a patient has reflux is not known. Our case challenges the currently defined time course of “long-standing” reflux symptoms for the development of BE, and supports the role of duodenal secretions alone in the development of BE. A 68-yr-old Caucasian man was admitted with weight loss, left upper quadrant pain, a hemoglobin of 6.8, and heme-positive stool. Esophagogastroduodenoscopy (EGD) revealed normal esophageal mucosa and a mass in the gastric cardia. Biopsies showed moderately differentiated gastric adenocarcinoma. The patient underwent a total gastrectomy, distal esophagectomy, and a Roux-en-Y esophagojejunostomy. Pathology confirmed gastric adenocarcinoma (T1 N0 Mx). The distal esophagus and gastroesophageal junction in the resected specimen were grossly and microscopically normal. Six months later an EGD, prompted by new complaints of regurgitation and dyspepsia, revealed distal esophageal mucosa lined by red-colored columnar tissue. Biopsies showed intestinal type epithelium. Thus, our case reports contribution to the current literature is twofold. It provides evidence of development of BE solely from duodenal reflux, and it documents a relatively short time span to development of BE.