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Prateek Sharma

Publications and source records attributed to Prateek Sharma.

At least 37 records · Page 2Linked to original sources
PubMed2005

Barrett's esophagus.

PURPOSE OF REVIEW: Significant advances have been made over the past year to identify individuals with Barrett's esophagus, who are at increased risk of malignant transformation. We summarize some of the important advances in that regard including: improved understanding in areas of epidemiology of those with Barrett's esophagus, identification of the pathways responsible for dysplastic and metaplastic development, selection of patient populations who would most benefit from surveillance protocols, and identification of biomarkers signifying progression of metaplastic changes. RECENT FINDINGS: Barrett's esophagus is being better recognized in patients presenting with extra-esophageal symptoms of gastroesophageal reflux such as chronic cough and asthma. Recent reports from some surgical series further suggest the importance of gastric and even duodenal reflux in the etiology of esophageal metaplastic development. In vitro experiments using acidic environments, to stimulate MAPK pathways, suggest an etiology for increased COX-2 expression. There appears to be a select group of individuals with familial predilection for the development of Barrett's esophagus. Retrospective studies continue to show apparent survival benefit in individuals with Barrett's esophagus undergoing surveillance endoscopy. Endoscopic ablative therapy may provide clinicians an attractive alternative to surgical resection in individuals with high-grade esophageal dysplasia and early adenocarcinoma. SUMMARY: The past year has brought many advances in the epidemiology, pathogenesis, surveillance, and treatment of those with Barrett's esophagus. Clinicians will benefit from review of these advances, and use of the most up-to-date data to ensure better patient outcomes.

Adenocarcinoma↗
PubMed2004

Barrett esophagus: will effective treatment prevent the risk of progression to esophageal adenocarcinoma?

Barrett esophagus is a complication of long-standing gastroesophageal reflux disease (GERD) and is the well-recognized premalignant condition for the majority of esophageal and gastroesophageal junction adenocarcinomas. Although duration of gastroesophageal reflux (GER), male sex, and, possibly, a strong family history are directly related to risk of Barrett esophagus, the role of screening in those with GERD and surveillance in those with confirmed Barrett syndrome remains controversial. Acid suppression with proton pump inhibitor (PPI) therapy plays a pivotal role in the management of symptoms in persons with chronic GER and Barrett esophagus. Although there is no conclusive evidence for the role of PPIs in regression of Barrett epithelium or prevention of dysplasia, longer-term studies that titrate the dose to normalization of esophageal pH may proffer different data in the future. Although highly touted in the literature, surgical and endoscopic ablation therapies are limited by several factors, including high rates of symptom recurrence, persistently abnormal pH values, need for repeat surgery, and, in the case of endoscopic therapy, residual Barrett metaplasia that can progress to high-grade dysplasia or cancer. These invasive interventions should only be considered after consultation with a gastroenterologist. Cancer chemoprevention strategies are just emerging, and their roles as direct chemoprotectants remain to be determined.

Adenocarcinoma↗
PubMed2004

High-resolution chromoendoscopy in the esophagus.

The major role for chromoendoscopy in the esophagus is the identification of premalignant or early cancerous lesions. In combination with high-resolution or magnification endoscopes, chromoendoscopy can potentially increase the diagnostic yield of clinically relevant lesions. Preliminary data have indicated a good correlation of findings using this technique to histopathologic readings. The ultimate goal of chromoendoscopy in combination with high resolution/magnification endoscopy is the determination of histology without obtaining tissue samples. In this article we review the different stains, the technical aspects, and current data in esophageal chromoendoscopy. We summarize possible clinical applications of these techniques and future directions of their use in esophageal diseases.

Barrett Esophagus↗
PubMed2004

Chromoendoscopy and magnification endoscopy for diagnosing esophageal cancer and dysplasia.

Based on preliminary reports, the use of chromoendoscopy and magnification endoscopy appears to be a valuable adjunct to standard endoscopy for the detection and classification of metaplastic and dysplastic lesions of the esophagus. Ideally, the use of this technique would enable the endoscopist to rule in or out the presence of intestinal metaplasia and dysplastic/cancerous epithelium by obtaining only a minimal number of targeted biopsy specimens--or potentially taking no biopsies at all, which could transform upper endoscopy into a much more effective screening and surveillance tool. There are several problems with the use of chromoendoscopy and magnification endoscopy in the esophagus. This technique is operator-dependent (ie, dependent on the skill and experience of the endoscopist). Studies reporting the accuracy of chromoendoscopy remain mixed, especially for Barrett's esophagus and dysplasia, which is likely explained by differences in techniques and materials used in the investigations. Staining within the esophagus is often patchy and uneven. Poor spraying technique can exaggerate irregular uptake by the mucosa. There is a high false-positive rate when staining gastric-type epithelium or in the setting of inflammation. Areas of dysplasia or cancer might take up stain in an irregular manner or might not stain at all. Magnification only allows the endoscopist to observe small areas of mucosa at a time, increasing the overall difficulty of the procedure and procedure length. Currently, the greatest body of literature exists concerning the use of Lugol's solution for the diagnosis of squamous cell dysplasia/carcinoma of the esophagus and methylene blue for diagnosing Barrett's esophagus. If used consistently by practicing physicians, the accuracy of biopsies could be improved. If endoscopic ablative therapy for high-grade dysplasia and early carcinoma (eg, photodynamic therapy and endoscopic mucosal resection) becomes accepted, sensitive methods of detecting residual metaplastic or dysplastic epithelium after ablation will be needed to help guide additional endoscopic therapy. Chromoendoscopy and magnification endoscopy could prove helpful in this setting. Further research in this field needs to be performed. As a first step, a uniform classification system for staining and magnification patterns should be devised. Future studies could then be performed using consistent terminologies. More controlled investigations with larger numbers of patients must be performed before tissue staining and magnification endoscopy become a part of day-to-day endoscopic practice. Lugol's chromoendoscopy is a simple technique for the detection of synchronous squamous dysplasia and cancer, but a substantial amount of work remains to be performed for the validation of chromoendoscopy for the detection of Barrett's esophagus and dysplasia. The ultimate aim of chromoendoscopy and magnification endoscopy in the esophagus is to show improved outcomes (ie, early detection of cancer and improved survival). These goals have not yet been realized and will require welldesigned studies in the future.

Barrett Esophagus↗
PubMed2004

The prevalence of Barrett's esophagus and erosive esophagitis in patients undergoing upper endoscopy for dyspepsia in a VA population.

The purpose of this study was to establish the prevalence of Barrett's esophagus and erosive esophagitis in a group of patients undergoing upper endoscopy for dyspepsia. Computerized endoscopy records were retrospectively evaluated to identify patients who underwent upper endoscopy for dyspepsia. Objective findings were recorded, including the presence of Barrett's esophagus, erosive esophagitis, and peptic ulcer disease. Among 264 patients, Barrett's esophagus was found in 16 (6.1%). The mean length of Barrett's was 2.0 cm, and the majority (81.3%) was short segment. Erosive esophagitis was found in 62 patients (23.%), and peptic ulcer disease was found in 25 patients (9.5%). Approximately 30% of patients undergoing endoscopy for dyspepsia had esophageal lesions. The prevalence of Barrett's in this population was 6%. Based on these results, a trial of acid suppression may benefit a third of patients with dyspepsia. Current screening practices for Barrett's in reflux patients alone may need to be reevaluated.

Adult↗
PubMed2004

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

BACKGROUND & AIMS: The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues. METHODS: A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion. RESULTS: There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia. CONCLUSIONS: Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Adenocarcinoma↗
PubMed2004

Barrett esophagus.

PURPOSE OF REVIEW: Strides have been made in the past year to identify means of decreasing mortality from esophageal adenocarcinoma. This requires a thorough understanding of the risk factor for its development, Barrett esophagus. This article summarizes the most up-to-date and important advancements involving the epidemiology, screening, pathogenesis, surveillance, and treatment of Barrett esophagus over the past year. RECENT FINDINGS: Much of the literature over the past year involving Barrett esophagus centered on selecting subsets of patients who would benefit most from screening and surveillance protocols. Risk factors such as increasing age, heartburn symptoms, increasing length of Barrett's segment, and male sex are increasingly identified as increasing the risk for malignant esophageal transformation. New technologies, using smaller endoscopes, may allow more cost-effective screening in selected patient populations. Methylene blue continues to grow in acceptance for its utility in assisting identification of Barrett esophagus during endoscopy. Some concern has been raised recently about DNA damage secondary to the use of methylene blue, but the clinical significance of this is unknown. High-magnification endoscopy to identify certain mucosal patterns suggesting Barrett esophagus is also gaining acceptance, perhaps allowing more accurate surveillance in patients with this condition. Much controversy continues regarding the treatment of Barrett esophagus to prevent the development of esophageal adenocarcinoma. Data reports may show some advantage of surgical antireflux therapy in reducing the risk of adenocarcinoma, but a recent meta-analysis disputes this claim. Chromosomal abnormalities resulting in tumor suppressor dysfunction continue to be revealed. SUMMARY: The past year has brought many new advances involving the diagnosis, surveillance, and treatment of Barrett esophagus. It is important for physicians to be aware of these developments, to identify individuals in whom interventions may be undertaken to decrease the risk of the development of esophageal adenocarcinoma.

Journal Article↗
PubMed2004

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

OBJECTIVES: Prospective evaluation of Barrett's esophagus (BE) in order to determine what demographic, endoscopic, and histologic features are predictive of the prevalence and incidence of Barrett's high-grade dysplasia (HGD) and adenocarcinoma (Ca). METHODS: Newly diagnosed BE patients were entered into and followed in a standardized surveillance protocol. The following features were examined using either forward, stepwise multiple regression analysis, or Cox proportional hazards to determine their ability to predict the presence of HGD or Ca at index BE diagnosis as well as their ability to predict progression of BE during follow-up: age, race, gender, length of BE in cm, size of a hiatal hernia, severity of dysplasia at index diagnosis as well as during surveillance, gastric Helicobacter pylori infection status, and type of medical acid-reflux treatment. RESULTS: A total of 550 patients were diagnosed with BE over the study period. Stepwise multiple regression analysis showed three factors significantly associated with index diagnosis of HGD or Ca: hiatal hernia (larger size), Barrett's length (longer length), and absence of H. pylori infection. Three hundred and twenty-four BE entered the surveillance protocol. Cox proportional hazards models revealed a significant and independent association for five factors predictive of the time to progression of BE: presence of dysplasia at index diagnosis (p < 0.001), severity of dysplasia during surveillance (p < 0.001), length of Barrett's epithelium (p= 0.012), size of hiatal hernia (p= 0.006), and gastric H. pylori infection status (p= 0.023). CONCLUSIONS: Endoscopic and histologic features of BE at initial diagnosis are predictive of index HGD and cancer as well as with risk of BE progression.

Adenocarcinoma↗
PubMed2004

Development of Barrett's esophagus six months after total gastrectomy.

Barrett's 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 report's 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.

Adenocarcinoma↗
PubMed2004

Detection of cardia intestinal metaplasia: do the biopsy number and location matter?

BACKGROUND AND AIM: Presence of intestinal metaplasia in the gastric cardia (cardia intestinal metaplasia, CIM) has been reported in 5-34% of patients undergoing upper endoscopy and is a topic of interest given the rising incidence of cancer in this location. The aim of this article is to determine the prevalence of CIM in biopsies obtained from two separate locations within the gastric cardia. METHODS: Patients presenting to the endoscopy unit for upper endoscopy for any symptoms were invited to participate in the study. The biopsy protocol included: eight biopsies from the gastric cardia, four from upper cardia (forceps across the squamocolumnar junction), four from lower cardia (within 1 cm of upper cardia), and four each from the gastric body and antrum. All cardia biopsies were stained with hematoxylin and eosin (H&E) and alcian blue at pH 2.5 for the presence of goblet cells and the body/antrum biopsies were stained with Steiner silver stain for Helicobacter pylori detection. In patients testing negative for H. pylori by histology, a serology test was performed. RESULTS: Sixty-five patients have been evaluated by this protocol; median age 54 yr (range: 34-81 yr), 63 males, 53 Caucasians, and 12 African Americans. The detection of CIM was as follows: upper cardia only, 7, both upper and lower cardia, 5, and lower cardia only, 7. Thus, CIM was detected in 12 patients (18%) in the upper cardia biopsies, in 12 patients (18%) in the lower cardia; overall prevalence of CIM was 29% (19 patients). Fifty-eight percent of CIM patients tested positive for H. pylori by either histology or serology. The addition of serology allowed for the detection of eight additional H. pylori-positive CIM patients. CONCLUSIONS: The prevalence of CIM in this study was similar (18%, four biopsies) at each location; however, if both locations were considered (eight biopsies), the prevalence increased to 29%. Thus, CIM prevalence may vary depending on the number of biopsies obtained as well as on the location of biopsies. Use of additional testing detects more patients who are H. pylori positive and should be performed if association of CIM with H. pylori is contemplated. Future endoscopic studies of the gastric cardia should specify the location of biopsies, the number of biopsies obtained, and the tests used to diagnose H. pylori.

Adult↗
PubMed2003

Chromoendoscopy and magnification endoscopy in Barrett's esophagus.

Chromoendoscopy and magnification endoscopy appear to be a valuable adjuncts for the detection and classification of BE. These techniques may also prove to be useful aids in surveillance protocols for identifying dysplastic epithelium or early cancer within a segment of BE. Ideally, the use of these techniques would enable the endoscopist to rule in or out the presence of IM and of dysplastic or cancerous epithelium by obtaining only a minimal number of targeted biopsy specimens, or potentially performing no biopsies at all. This could transform upper endoscopy into a much more effective screening and surveillance tool for BE. Several problems currently exist for the use of chromoendoscopy for BE. Results of studies reporting the accuracy of chromoendoscopy remain mixed,and are likely explained by the wide range of techniques and materials used in the investigations. Staining adds several steps, and likely several minutes, to an upper endoscopy. Staining within the esophagus is often patchy and uneven. In addition, poor spraying technique exaggerates the irregular uptake by the mucosa. There is a high false-positive rate when staining gastric-type epithelium and denuded epithelium. Areas of dysplasia or cancer may take up stain in an irregular manner, or may not stain at all. Chromoendoscopy is a relatively new technique in the management of BE and depends on the skill and experience of the endoscopist. Magnification, however, only allows the endoscopist to observe small areas of mucosa at a time, increasing the overall complexity and length of the procedure. The learning curve for this procedure is relatively short, however, and endoscopists can usually become proficient in the technique quickly. Currently, the greatest body of literature exists concerning the use of methylene blue for diagnosing BE. At the present time, chromoendoscopy and magnification endoscopy appear to be most beneficial in detecting IM in short segments of esophageal columnar-appearing mucosa. If used consistently by practicing physicians, the accuracy of biopsies for IM could be improved. If endoscopic ablative therapy for HGD and early adenocarcinoma becomes accepted, sensitive methods of detecting residual BE after ablation will be needed to help guide additional endoscopic therapy. Chromoendoscopy and magnification endoscopy could prove helpful in this setting. Further research in this field remains to be performed. As a first step, a uniform classification system for staining and magnification patterns should be devised. If investigators can reach a consensus, and validate classification, terminology, and pattern-types, future studies could be performed using "common and similar language." More controlled investigations with larger numbers of patients must be performed before tissue staining and magnification endoscopy become a part of the practicing endoscopist's armamentarium. The ultimate aims of chromoendoscopy and magnification endoscopy in the setting of BE are to show improved outcomes--namely, early detection of cancer and improved survival rates. These goals have not yet been realized and meeting them will require well-designed studies in the future.

Barrett Esophagus↗
PubMed2003

Barrett esophagus.

PURPOSE: The importance of an in-depth understanding about Barrett esophagus is ultimately to decrease the mortality and morbidity from esophageal adenocarcinoma cancer by early detection of metaplasia and dysplasia and appropriate therapy. This review summarizes several publications in the past year related to the epidemiology, pathogenesis, screening and surveillance, new methods for detection of metaplasia/dysplasia, and advances in the treatment of Barrett esophagus. RECENT FINDINGS: Patients with Barrett esophagus are characterized by the presence of risk factors usually indicative of severe types of gastroesophageal reflux disease. Recent insights into epidemiology and pathogenesis have shown that the risk of high-grade dysplasia and adenocarcinoma may be related to the increasing length of Barrett esophagus, size of hiatus hernia, and severity of acid reflux. The role of smoking and alcohol consumption remains controversial. Increasing the number of biopsies by repeat standard endoscopy can enhance the yield of intestinal metaplasia in patients with suspected short-segment Barrett esophagus. Costs of surveillance using standard endoscopy and random biopsies would be very high and using special techniques to target specific areas could ultimately help in cost reduction. Emerging data on new techniques and technology such as vital staining with methylene blue and protoporphyrin fluorescence can increase the yield of metaplasia and dysplasia. Biomarkers studies have revealed that p53 mutation by the loss of heterozygosity can help detect patients with low and high risk for cancer progression. Studies thus far have been unclear whether acid suppression alone can impact the malignant progression in Barrett esophagus patients. Inhibition of cyclooxygenase by aspirin or nonsteroidal anti-inflammatory drugs may be a promising chemoprevention strategy against dysplasia and esophageal adenocarcinoma development as shown in some recent studies. Nonsurgical treatment by photodynamic therapy or mucosal resection may be a less invasive and organ-sparing option for some patients with high-grade dysplasia and early adenocarcinoma. SUMMARY: In the past year we have made major strides in our knowledge of this premalignant lesion. Recent studies have shed light in a better understanding of the epidemiology of Barrett esophagus, including clinical and endoscopic factors associated with high-grade dysplasia or esophageal adenocarcinoma and various biomarkers that would identify patient subsets with low and high risk for cancer progression. This will eventually have significant implications on the screening, surveillance, and treatment of the disease. Advanced endoscopic therapies including mucosectomy or photodynamic therapy may be emerging options in patients with intraepithelial neoplasia.

Journal Article↗
PubMed2002

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.

Barrett Esophagus↗
PubMed2002

Barrett esophagus.

A number of publications have provided valuable insight into and data on the epidemiology, pathogenesis, diagnosis, risk factor evaluation, and treatment of patients with Barrett esophagus. Although the incidence of esophageal adenocarcinoma has rapidly increased over the past two decades, it is not clear whether there has been a parallel increase in the frequency of Barrett esophagus. The issue of surveillance endoscopy in patients with Barrett esophagus remains controversial; prospective data are still lacking. Bile reflux plays an important role in the pathogenesis of Barrett esophagus; however, this usually occurs in the presence of acid. Newer technology and techniques, including chromoendoscopy, magnification endoscopy, optical coherence tomography, and spectroscopy, have opened the field by providing a more accurate and "nonbiopsy" diagnosis of intestinal metaplasia and dysplasia. The field of biomarkers remains continues to expand and is providing insight into risk stratification of patients with Barrett esophagus. The exact role of acid suppression in patients with this premalignant disease remains controversial, and endoscopic therapies appear promising.

Journal Article↗