What is it?|
A precancerous condition in which cells which are very similar to cancer cells grow in an organ but have not yet acquired the ability to invade into tissue or metastasize (spread to areas distant from where they started). This is a stage which can be cured.
Treatment for Varying Degrees of Dysplasia:
|Barrett's esophagus with:
Commonly Recommended Treatment:|
Atypia indefinite for dysplasia
Patients will need to undergo a repeat endoscopic examination after an 8- to 12-week course of intensive acid suppression.
Low-grade dysplasia (pre-cancerous change)
Antireflux therapy (either medical or surgical) is recommended, followed by endoscopic surveillance every 1-3 years.|
(severe precancerous change)
Antireflux therapy plus additional therapy prescribed individually on the basis of histologic findings, coexistent disease, and the operative risks (see below). Additional therapy may include surveillance endoscopy every 3-6 months, photodynamic therapy, endoscopic mucosal resection, or surgery. |
Identifying Dysplasia using Endoscopy
Surveillance endoscopy for Barrett's Esophagus - Regular endoscopic surveillance for dysplasia is recommended for patients with Barrett's esophagus. Early identification and therapy of dysplasia and adenocarcinoma has been associated with improved survival, although there is some controversy about the frequency of endoscopic surveillance needed.
Methylene blue chromoendoscopy
This technique, which involves spraying a blue dye in the esophagus, is used to improve identification of suspicious areas of the esophageal mucosa. The methylene blue temporarily stains the mucosa, helping identify areas of dysplasia and early cancers to help identify the best places to obtain biopsies. Research studies have showed variable success using this technique to identify dysplasia but may be effective when used by experienced endoscopists.
Confocal laser endomicroscopy
Confocal laser endomicroscopy (CLE) is a new method for examining mucosal histology in real-time during an endoscopic procedure. The confocal endomicroscope is a standard endoscope with a microscope built into the tip. It magnifies the mucosa 1000 times normal, so microscopic pictures of cells can be obtained. Normal esophageal cells can be distinguished from Barret's esophagus, dysplasia, and cancers. One study has shown that confocal endomicroscopy may provide accurate in vivo imaging and targeted biopsy of Barrett's esophagus and associated neoplasia and further studies are planned.
Optical coherence tomography
Optical coherence tomography (OCT) relies on light scattering by tissues. It has been used in research studies to identify high grade dysplasia and early cancers in Barrett's esophagus. Further work is ongoing to improve the ability to identify dysplasia and small cancers in Barrett's esophagus.
Autofluorescence imaging (AFI) involves using laser light during endoscopy to stimulate the natural fluorescence of the esophageal mucosa. The fluorescence is captured and processed by a computer showing the difference between normal and abnormal mucosa that can be seen during the endoscopic procedure. AFI has a may prove to be an excellent method for scanning large areas of mucosa for neoplasia. In a single center prospective study, there was a small but significant benefit of AFI over standard white light endoscopy. The standard endoscopy image and autofluorescence image could potentially allow the endoscopist to identify the most suspicious areas to biopsy and further research is ongoing.
Narrow Band Imaging
Narrow band imaging (NBI) is a method that uses special filters on the endoscope to narrow the color spectrum of red, green, and blue light and increase the intensity of the blue light. When NBI is combined with high magnification or high resolution endoscopy, the detailed pattern of the mucosa and blood vessels can be seen in Barrett's esophagus. Some studies have shown small, but significant benefit to adding NBI to high resolution endoscopy for identifying high grade dysplasia and early cancers in Barrett's esophagus. Additional studies are looking at the benefit of NBI.
Treatment of High Grade Dysplasia
When high-grade dysplasia has been identified, the patient's Barrett's esophagus is "mapped" to localize the areas of dysplasia and look for very small adenocarcinomas. Four biopsies around the esophagus are generally taken every 1-2 centimeters. Other techniques to help identify dysplasia, such as chromoendoscopy, AFI, high resolution endoscopy, NBI, may be used to help locate the areas to biopsy. This Barrett's esophagus map can be used as a reference for subsequent surveillance procedures.
Endoscopic Surveillance for High-Grade Dysplasia
Endoscopic surveillance for high-grade dysplasia consists of repeat endoscopy with many mucosal biopsies every 3 months until a cancer is detected. This may be an option for patients who have only a small area of high-grade dysplasia. The incidence of adenocarcinoma in patients with confirmed high-grade dysplasia treated only with omeprazole was 20% in a prospective multicenter trial. In some cases, "watchful waiting" may be appropriate but only if endoscopic surveillance is frequent.
Medications that suppress acid production and reduce reflux may help reduce inflammation and decrease futher development of dysplasia. Some research studies have suggested that dysplasia and Barrett's Esophagus may regress (decrease) with proton pump inhibitors, but often other therapies are recommended. Most patients with Barrett's Esophagus undergoing surveillance endoscopy or other therapy for high-grade dysplasia will be treated with medications to reduce acid reflux.
Photodynamic therapy with profimer sodium
Photodynamic therapy (PDT) involves intravenous administration of a photosensitizing agent, porfimer sodium, which is an inactive compound until it is exposed to light. Another agent that is used is 5-aminolevulinic acid which is given orally. The light-sensitive molecules accumulate in the skin and in the lining of the esophagus, particularly in areas of Barrett's esophagus and neoplastic cells. When exposed to a certain wavelength of laser light, the agents produce cytotoxic oxygen free radicals that kill nearby cells. Patients treated with porfimer sodium need to avoid direct sunlight for about 4-6 weeks after treatment as their skin will be very sensitive to sunburn. The main complication of PDT is esophageal strictures, which occur in 10-30% of treated patients, depending on the depth of tissue damage. Additionally, some patients have incomplete eradication of their neoplastic cells, so Barrett's lesions may recur and continued surveillance endoscopy is indicated after treatment.
Argon plasma coagulation
Argon plasma coagulation (APC) is a method that uses ionized argon gas to conduct a high-frequency electrical current to tissues. APC causes necrosis of the surface tissues and has been used to ablate high grade dysplasia.
Other ablative therapies
Two new ablative therapies still under evaluation are radiofrequency ablation and cryotherapy. Both devices are approved for clinical use by the Food and Drug Administration but there is little published evidence of their long-term safety and efficacy for treating Barrett's esophagus and associated neoplasia.
Endoscopic Mucosal Resection
Endoscopic mucosal resection (EMR) is a technique for removing cancers or areas of high grade dysplasia from the esophagus by removing the mucosal layer of the esophagus around the area of concern. The goal of EMR is to completely remove the diseased area and all samples are examined in detail by a pathologist. This technique can be used in combination with other ablation techniques, such as PDT or APC with excellent results. EMR may also be used in the staging of BE-associated cancers and may help predict the chance of local recurrence of cancers.
Patients with high-grade dysplasia or esophageal adenocarcinoma can be treated with esophagectomy (surgical removal of the esophagus) and esophagogastric anastomosis (hooking up the remaining esophagus to the stomach). Surgical resection (removal) is reserved for patients in whom there is the prospect for cure. Appropriate extensive resection may be justified when high-grade dysplasia has been confirmed but when invasive adenocarcinoma has not been identified by biopsy. Prolonged delay of resection may result in undue risk of spread of tumor to a degree which is no longer curable. Besides esophagectomy, patients may also require additional antireflux therapy with intensive endoscopic surveillance. Results have shown that early detection of adenocarcinoma and subsequent esophageal resection preferably at the stage of high-grade dsyplasia is important in terms of survival