Barrett's esophagus | |
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Other names | Barrett's oesophagus, Allison-Johnstone anomaly, columnar epithelium lined lower oesophagus (CELLO) |
Endoscopic image of Barrett's esophagus, which is the area of dark reddish-brown mucosa at the base of the esophagus. (Biopsies showed intestinal metaplasia.) | |
Specialty | Gastroenterology General surgery |
Symptoms | Nausea |
Barrett's esophagus is a condition in which there is an abnormal (metaplastic) change in the mucosal cells lining the lower portion of the esophagus, from stratified squamous epithelium to simple columnar epithelium with interspersed goblet cells that are normally present only in the small intestine and large intestine. This change is considered to be a premalignant condition because of its potential to further transition to esophageal adenocarcinoma, an often-deadly cancer. [1] [2]
The main cause of Barrett's esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis. [3] Barrett's esophagus is diagnosed by endoscopy: observing the characteristic appearance of this condition by direct inspection of the lower esophagus; followed by microscopic examination of tissue from the affected area obtained from biopsy. The cells of Barrett's esophagus are classified into four categories: nondysplastic, low-grade dysplasia, high-grade dysplasia, and frank carcinoma. High-grade dysplasia and early stages of adenocarcinoma may be treated by endoscopic resection or radiofrequency ablation. [4] Later stages of adenocarcinoma may be treated with surgical resection or palliation. Those with nondysplastic or low-grade dysplasia are managed by annual observation with endoscopy, or treatment with radiofrequency ablation. In high-grade dysplasia, the risk of developing cancer might be at 10% per patient-year or greater. [1]
The incidence of esophageal adenocarcinoma has increased substantially in the Western world in recent years. [1] The condition is found in 5–15% of patients who seek medical care for heartburn (gastroesophageal reflux disease, or GERD), although a large subgroup of patients with Barrett's esophagus are asymptomatic. The condition is named after surgeon Norman Barrett (1903–1979) even though the condition was originally described by Philip Rowland Allison in 1946. [5] [6] [7]
The change from normal to premalignant cells indicate Barrett's esophagus does not cause any particular symptoms. Barrett's esophagus, however, is associated with these symptoms:[ citation needed ]
The risk of developing Barrett's esophagus is increased by central obesity (vs. peripheral obesity). [8] The exact mechanism is unclear. The difference in distribution of fat among men (more central) and women (more peripheral) may explain the increased risk in males. [9]
Barrett's esophagus occurs due to chronic inflammation. The principal cause of chronic inflammation is gastroesophageal reflux disease, GERD (UK: GORD). In this disease, acidic stomach, bile, and small intestine and pancreatic contents cause damage to the cells of the lower esophagus. In turn, this provokes an advantage for cells more resistant to these noxious stimuli in particular HOXA13-expressing stem cells that are characterised by distal (intestinal) characteristics and outcompete the normal squamous cells. [10]
This mechanism also explains the selection of HER2/neu (also called ERBB2) and the overexpressing (lineage-addicted) cancer cells during the process of carcinogenesis, and the efficacy of targeted therapy against the Her-2 receptor with trastuzumab (Herceptin) in the treatment of adenocarcinomas at the gastroesophageal junction.[ citation needed ]
Researchers are unable to predict who with heartburn will develop Barrett's esophagus. While no relationship exists between the severity of heartburn and the development of Barrett's esophagus, a relationship does exist between chronic heartburn and the development of Barrett's esophagus. Sometimes, people with Barrett's esophagus have no heartburn symptoms at all.[ citation needed ]
Some anecdotal evidence indicates those with the eating disorder bulimia are more likely to develop Barrett's esophagus because bulimia can cause severe acid reflux, and because purging also floods the esophagus with acid. However, a link between bulimia and Barrett's esophagus remains unproven. [11] [12]
During episodes of reflux, bile acids enter the esophagus, and this may be an important factor in carcinogenesis. [13] Individuals with GERD and BE are exposed to high concentrations of deoxycholic acid that has cytotoxic effects and can cause DNA damage. [13] [14]
Both macroscopic (from endoscopy) and microscopic positive findings are required to make a diagnosis. Barrett's esophagus is marked by the presence of columnar epithelia in the lower esophagus, replacing the normal squamous cell epithelium—an example of metaplasia. The secretory columnar epithelium may be more able to withstand the erosive action of the gastric secretions; however, this metaplasia confers an increased risk of adenocarcinoma. [15]
Screening endoscopy is recommended among males over the age of 60 who have reflux symptoms that are of long duration and not controllable with treatment. [16] Among those not expected to live more than five years screening is not recommended. [16]
The Seattle protocol is used commonly in endoscopy to obtain endoscopic biopsies for screening, taken every 1 to 2 cm from the gastroesophageal junction.[ citation needed ]
Since the COVID-19 pandemic In Scotland, the local NHS started using a swallowable sponge (Cytosponge) in hospitals to collect cell samples for diagnosis. [17] Preliminary studies have shown this diagnostic test to be a useful tool for screening people with heartburn symptoms and improved diagnosis. [18] [19]
The presence of goblet cells, called intestinal metaplasia, is necessary to make a diagnosis of Barrett's esophagus. This frequently occurs in the presence of other metaplastic columnar cells, but only the presence of goblet cells is diagnostic. The metaplasia is grossly visible through a gastroscope, but biopsy specimens must be examined under a microscope to determine whether cells are gastric or colonic in nature. Colonic metaplasia is usually identified by finding goblet cells in the epithelium and is necessary for the true diagnosis. [20] [ citation needed ]
Many histologic mimics of Barrett's esophagus are known (i.e. goblet cells occurring in the transitional epithelium of normal esophageal submucosal gland ducts, "pseudogoblet cells" in which abundant foveolar [gastric] type mucin simulates the acid mucin true goblet cells). Assessment of relationship to submucosal glands and transitional-type epithelium with examination of multiple levels through the tissue may allow the pathologist to reliably distinguish between goblet cells of submucosal gland ducts and true Barrett's esophagus (specialized columnar metaplasia). The histochemical stain Alcian blue pH 2.5 is also frequently used to distinguish true intestinal-type mucins from their histologic mimics. Recently, immunohistochemical analysis with antibodies to CDX-2 (specific for mid and hindgut intestinal derivation) has also been used to identify true intestinal-type metaplastic cells. The protein AGR2 is elevated in Barrett's esophagus [21] and can be used as a biomarker for distinguishing Barrett epithelium from normal esophageal epithelium. [22]
The presence of intestinal metaplasia in Barrett's esophagus represents a marker for the progression of metaplasia towards dysplasia and eventually adenocarcinoma. This factor combined with two different immunohistochemical expression of p53, Her2 and p16 leads to two different genetic pathways that likely progress to dysplasia in Barrett's esophagus. [23] Also intestinal metaplastic cells can be positive for CK 7+/CK20-. [24]
After the initial diagnosis of Barrett's esophagus is rendered, affected persons undergo annual surveillance to detect changes that indicate higher risk to progression to cancer: development of epithelial dysplasia (or "intraepithelial neoplasia"). [25] Among all metaplastic lesions, around 8% were associated with dysplasia. particularly a recent study demonstrated that dysplastic lesions were located mainly in the posterior wall of the esophagus. [26]
Considerable variability is seen in assessment for dysplasia among pathologists. Recently, gastroenterology and GI pathology societies have recommended that any diagnosis of high-grade dysplasia in Barrett be confirmed by at least two fellowship-trained GI pathologists prior to definitive treatment for patients. [15] For more accuracy and reproducibility, it is also recommended to follow international classification systems, such as the "Vienna classification" of gastrointestinal epithelial neoplasia (2000). [27]
Many people with Barrett's esophagus do not have dysplasia. Medical societies recommend that if a patient has Barrett's esophagus, and if the past two endoscopy and biopsy examinations have confirmed the absence of dysplasia, then the patient should not have another endoscopy within three years. [28] [29] [30]
Endoscopic surveillance of people with Barrett's esophagus is often recommended, although little direct evidence supports this practice. [1] Treatment options for high-grade dysplasia include surgical removal of the esophagus (esophagectomy) or endoscopic treatments such as endoscopic mucosal resection or ablation (destruction). [1]
The risk of malignancy is highest in the United States in Caucasian men over fifty years of age with more than five years of symptoms. Current recommendations include routine endoscopy and biopsy (looking for dysplastic changes). Although in the past physicians have taken a watchful waiting approach, newly published research supports consideration of intervention for Barrett's esophagus. Balloon-based radiofrequency ablation, invented by Ganz, Stern, and Zelickson in 1999, is a new treatment modality for the treatment of Barrett's esophagus and dysplasia and has been the subject of numerous published clinical trials. [31] [32] [33] [34] The findings demonstrate radiofrequency ablation is at least 90% effective to completely clear Barrett's esophagus and dysplasia, with durability of up to five years and a favorable safety profile. [31] [32] [33] [34]
Anti-reflux surgery has not been proven to prevent esophageal cancer. However, the indication[ who? ] is that proton pump inhibitors are effective in limiting the progression of esophageal cancer[ citation needed ]. Laser treatment is used in severe dysplasia, while overt malignancy may require surgery, radiation therapy, or systemic chemotherapy. A recent five-year random-controlled trial has shown that photodynamic therapy using photofrin is statistically more effective in eliminating dysplastic growth areas than sole use of a proton pump inhibitor. [35]
There is presently no reliable way to determine which patients with Barrett's esophagus will go on to develop esophageal cancer, although a recent study found the detection of three different genetic abnormalities was associated with as much as a 79% chance of developing cancer in six years. [36]
Endoscopic mucosal resection has also been evaluated as a management technique. [37] Additionally an operation known as a Nissen fundoplication can reduce the reflux of acid from the stomach into the esophagus. [38]
In a variety of studies, nonsteroidal anti-inflammatory drugs (NSAIDS) such as low-dose aspirin (75–300 mg/day) have shown evidence of preventing esophageal cancer in people with Barrett's esophagus. [39] [40] [41] [42]
Barrett's esophagus is a pre-malignant condition, not a cancerous one.[ citation needed ]
A small subset of patients with Barrett's esophagus will eventually develop malignant esophagogastric junctional adenocarcinoma, which has a mortality rate of over 85%. [43]
The risk of developing esophageal adenocarcinoma increases based on how severe the Barrett's esophagus has become. [44] Longer length of the Barrett's esophagus region is also associated with increased risk of developing cancer. [44] [45]
Progression and severity of Barrett's esophagus is measured by amount of dysplasia the cells show. Dysplasia is scored on a five-tier system: [45]
A 2016 study found that the rate of progression to esophageal adenocarcinoma in Barrett's esophagus patients with no dysplasia, low-grade dysplasia, and high-grade dysplasia are around 0.6%, 13.4%, and 25%, respectively. [46]
However, for low-grade dysplasia, the true yearly rate of progression to cancer remains difficult to estimate, as results are highly variable from study to study, from 13.4% down to 0.84%. [44] This is partly due to each study having a different mix of intermediate disease states being combined under the umbrella diagnosis of LGD. [45]
The incidence in the United States among Caucasian men is eight times the rate among Caucasian women and five times greater than African American men. Overall, the male to female ratio of Barrett's esophagus is 10:1. [47] Several studies have estimated the prevalence of Barrett's esophagus in the general population to be 1.3% to 1.6% in two European populations (Italian [48] and Swedish [49] ), and 3.6% in a Korean population. [50]
The condition is named after Australian thoracic surgeon Norman Barrett (1903–1979), who in 1950 argued that "ulcers are found below the squamocolumnar junction ... represent gastric ulcers within 'a pouch of stomach ... drawn up by scar tissue into the mediastinum' ... representing an example of a 'congenital short esophagus'". [51] [52] In contrast, Philip Rowland Allison and Alan Johnstone argued that the condition related to the "esophagus lined with gastric mucous membrane and not intra-thoracic stomach as Barrett mistakenly believed." [53] [6] Philip Allison, cardiothoracic surgeon and Chair of Surgery at the University of Oxford, suggested "calling the chronic peptic ulcer crater of the esophagus a 'Barrett's ulcer'", but added this name did not imply agreement with "Barrett's description of an esophagus lined with gastric mucous membrane as stomach." [53] [6] Bani-Hani KE and Bani-Hani KR argue that the terminology and definition of Barrett's esophagus is surrounded by extraordinary confusion unlike most other medical conditions and that "[t]he use of the eponym 'Barrett's' to describe [the condition] is not justified from a historical point of view". [6] Bani-Hani KE and Bani-Hani KR investigated the historical aspects of the condition and found they could establish "how little Norman Barrett had contributed to the core concept of this condition in comparison to the contributions of other investigators, particularly the contribution of Philip Allison". [6]
A further association was made with adenocarcinoma in 1975. [54]
Gastroenterology is the branch of medicine focused on the digestive system and its disorders. The digestive system consists of the gastrointestinal tract, sometimes referred to as the GI tract, which includes the esophagus, stomach, small intestine and large intestine as well as the accessory organs of digestion which include the pancreas, gallbladder, and liver.
The esophagus or oesophagus, colloquially known also as the food pipe, food tube, or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about 25 cm (10 in) long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word oesophagus is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω + ἔφαγον.
Esophageal achalasia, often referred to simply as achalasia, is a failure of smooth muscle fibers to relax, which can cause the lower esophageal sphincter to remain closed. Without a modifier, "achalasia" usually refers to achalasia of the esophagus. Achalasia can happen at various points along the gastrointestinal tract; achalasia of the rectum, for instance, may occur in Hirschsprung's disease. The lower esophageal sphincter is a muscle between the esophagus and stomach that opens when food comes in. It closes to avoid stomach acids from coming back up. A fully understood cause to the disease is unknown, as are factors that increase the risk of its appearance. Suggestions of a genetically transmittable form of achalasia exist, but this is neither fully understood, nor agreed upon.
Heartburn, also known as pyrosis, cardialgia or acid indigestion, is a burning sensation in the central chest or upper central abdomen. Heartburn is usually due to regurgitation of gastric acid into the esophagus. It is the major symptom of gastroesophageal reflux disease (GERD).
Gastroesophageal reflux disease (GERD) or gastro-oesophageal reflux disease (GORD) is a chronic upper gastrointestinal disease in which stomach content persistently and regularly flows up into the esophagus, resulting in symptoms and/or complications. Symptoms include dental corrosion, dysphagia, heartburn, odynophagia, regurgitation, non-cardiac chest pain, extraesophageal symptoms such as chronic cough, hoarseness, reflux-induced laryngitis, or asthma. In the long term, and when not treated, complications such as esophagitis, esophageal stricture, and Barrett's esophagus may arise.
Esophageal cancer is cancer arising from the esophagus—the food pipe that runs between the throat and the stomach. Symptoms often include difficulty in swallowing and weight loss. Other symptoms may include pain when swallowing, a hoarse voice, enlarged lymph nodes ("glands") around the collarbone, a dry cough, and possibly coughing up or vomiting blood.
Stomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lymphomas and mesenchymal tumors may also develop in the stomach. Early symptoms may include heartburn, upper abdominal pain, nausea, and loss of appetite. Later signs and symptoms may include weight loss, yellowing of the skin and whites of the eyes, vomiting, difficulty swallowing, and blood in the stool, among others. The cancer may spread from the stomach to other parts of the body, particularly the liver, lungs, bones, lining of the abdomen, and lymph nodes.
Metaplasia is the transformation of a cell type to another cell type. The change from one type of cell to another may be part of a normal maturation process, or caused by some sort of abnormal stimulus. In simplistic terms, it is as if the original cells are not robust enough to withstand their environment, so they transform into another cell type better suited to their environment. If the stimulus causing metaplasia is removed or ceases, tissues return to their normal pattern of differentiation. Metaplasia is not synonymous with dysplasia, and is not considered to be an actual cancer. It is also contrasted with heteroplasia, which is the spontaneous abnormal growth of cytologic and histologic elements. Today, metaplastic changes are usually considered to be an early phase of carcinogenesis, specifically for those with a history of cancers or who are known to be susceptible to carcinogenic changes. Metaplastic change is thus often viewed as a premalignant condition that requires immediate intervention, either surgical or medical, lest it lead to cancer via malignant transformation.
Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The symptoms relate to the organ affected and can include obstruction, abnormal bleeding or other associated problems. The diagnosis often requires endoscopy, followed by biopsy of suspicious tissue. The treatment depends on the location of the tumor, as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere. These factors also determine the prognosis.
Eosinophilic esophagitis (EoE) is an allergic inflammatory condition of the esophagus that involves eosinophils, a type of white blood cell. In healthy individuals, the esophagus is typically devoid of eosinophils. In EoE, eosinophils migrate to the esophagus in large numbers. When a trigger food is eaten, the eosinophils contribute to tissue damage and inflammation. Symptoms include swallowing difficulty, food impaction, vomiting, and heartburn.
Esophageal dysphagia is a form of dysphagia where the underlying cause arises from the body of the esophagus, lower esophageal sphincter, or cardia of the stomach, usually due to mechanical causes or motility problems.
Stretta is a minimally invasive endoscopic procedure for the treatment of gastroesophageal reflux disease (GERD) that delivers radiofrequency energy in the form of electromagnetic waves through electrodes at the end of a catheter to the lower esophageal sphincter (LES) and the gastric cardia – the region of the stomach just below the LES. The energy heats the tissue, ultimately causing it to swell and stiffen; the way this works was not understood as of 2015, but it was thought that perhaps the heat causes local inflammation, collagen deposition and muscular thickening of the LES and that it may disrupt the nerves there.
Norman Rupert Barrett CBE FRSA was an Australian-born British thoracic surgeon who is widely yet mistakenly remembered for describing what became known as Barrett's oesophagus.
Therapeutic endoscopy is the medical term for an endoscopic procedure during which treatment is carried out via the endoscope. This contrasts with diagnostic endoscopy, where the aim of the procedure is purely to visualize a part of the gastrointestinal, respiratory or urinary tract in order to aid diagnosis. In practice, a procedure which starts as a diagnostic endoscopy may become a therapeutic endoscopy depending on the findings, such as in cases of upper gastrointestinal bleeding, or the finding of polyps during colonoscopy.
Intestinal metaplasia is the transformation (metaplasia) of epithelium into a type of epithelium resembling that found in the intestine. In the esophagus, this is called Barrett's esophagus. Chronic inflammation caused by H. pylori infection in the stomach and GERD in the esophagus are seen as the primary instigators of metaplasia and subsequent adenocarcinoma formation. Initially, the transformed epithelium resembles the small intestine lining; in the later stages it resembles the lining of the colon. It is characterized by the appearance of goblet cells and expression of intestinal cell markers such as the transcription factor, CDX2.
Chromoendoscopy is a medical procedure wherein dyes are instilled into the gastrointestinal tract at the time of visualization with fibre-optic endoscopy. The purpose of chromoendoscopy is chiefly to enhance the characterization of tissues, although dyes may be used for other functional purposes. The detail achieved with chromoendoscopy can often allow for identification of the tissue type or pathology based upon the pattern uncovered.
Oesophagogastric junctional adenocarcinoma is a cancer of the lower part of the oesophagus with a rising incidence in Western countries. This disease is often linked to Barrett's oesophagus.
Gastrointestinal intraepithelial neoplasia is also known as gastrointestinal dysplasia. Gastrointestinal dysplasia refers to abnormal growth of the epithelial tissue lining the gastrointestinal tract including the esophagus, stomach, and colon. Pancreatic, biliary, and rectal Intraepithelial Neoplasia are discussed separately. The regions of abnormal growth are confined by the basement membrane adjacent to the epithelial tissue and are thought to represent pre-cancerous lesions.
Prateek SharmaFACG, FACP, FASGE is an Indian American gastroenterologist that specializes in esophageal diseases and endoscopic treatments.
Confocal endoscopy, or confocal laser endomicroscopy (CLE), is a modern imaging technique that allows the examination of real-time microscopic and histological features inside the body. In the word "endomicroscopy", endo- means "within" and -skopein means "to view or observe". CLE, also known as "optical biopsy", can analyse histology and cytology features of a tissue which otherwise is only possible by tissue biopsy. Similar to confocal microscopy, the laser in CLE filtered by the pinhole excites the fluorescent dye through a beam splitter and objective lens. The fluorescent emission then follows similar paths into the detector. A pinhole is used to select emissions from the desired focal plane. Two categories of CLE exist, namely probe-based (pCLE) and the less common endoscopy-based endoscopy (eCLE).