KTP laser destruction of dysplasia and early cancer in columnar-lined Barrett's esophagus

Therapeutic Upper Gastrointestinal Endoscopy in Pediatric Gastroenterology

This paper seeks to give a broad overview of pediatric upper gastrointestinal (GI) pathologies that we are now able to treat endoscopically, acquired or congenital, and we hope this delivers the reader an impression of what is increasingly available to pediatric endoscopists and their patients.

Real-time co-localized OCT surveillance of laser therapy using motion corrected speckle decorrelation

We present a system capable of real-time delivery and monitoring of laser therapy by imaging with optical coherence tomography (OCT) through a double-clad fiber (DCF). A double-clad fiber coupler is used to inject and collect OCT light into the core of a DCF and inject the therapy light into its larger inner cladding, allowing for both imaging and therapy to be perfectly coregistered. Monitoring of treatment depth is achieved by calculating the speckle intensity decorrelation occurring during tissue coagulation. Furthermore, an analytical noise correction was used on the correlation to extend the maximum monitoring depth. We also present a method for correcting motion-induced decorrelation using a lookup table. Using the value of the noise- and motion-corrected correlation coefficient in a novel approach, our system is capable of identifying the depth of thermal coagulation in real time and automatically shut the therapy laser off when the targeted depth is reached. The process is demonstrated ex vivo in rat tongue and abdominal muscles for depths ranging from 500 µm to 1000 µm with induced motion in real time.

Use of potassium titanyl phosphate (KTP) laser Dermastat in the treatment of recurrent anterior epistaxis - a new technique

OBJECTIVE

To evaluate the short- to medium-term effectiveness of potassium titanyl phosphate (KTP) laser Dermastat in patients with recurrent anterior epistaxis.

METHOD

Fifty-eight patients presenting with recurrent anterior epistaxis were treated using potassium titanyl phosphate laser Dermastat. Those with recurrent epistaxis arising from prominent vessels in Little's area, and/or those for whom treatment with silver nitrate cautery failed, were included. The main outcome measure was resolution of epistaxis at two months.

RESULTS

Fifty-eight patients were treated; 27 were under 18 years old. Thirty patients had prominent vessels. Thirty-one patients had undergone previous cautery treatment. Thirty-eight patients had treatment to the left side, 19 to the right and 1 to both. At two months, 74 per cent reported resolution of epistaxis with no complications. This increased to 78 per cent at further follow up.

CONCLUSION

Our technique is a successful, safe treatment for recurrent anterior epistaxis in an otherwise treatment-resistant group. A single procedure is effective. The handpiece and tip are reusable and sterilisable, resulting in cost-effectiveness.

Endoscopic options for treatment of dysplasia in Barrett’s esophagus

Recent advances in the endoscopic treatment of dysplasia in Barrett’s esophagus (BE) have allowed endoscopists to provide effective and durable eradication therapies. This review summarizes the available endoscopic eradication techniques for dysplasia in patients with BE including endoscopic mucosal resection, endoscopic submucosal dissection, photodynamic therapy, argon plasma coagulation, radiofrequency ablation and cryotherapy.

Hyperthermia approaches for enhanced delivery of nanomedicines to solid tumors

Drug delivery to solid tumors has received much attention in order to reduce harmful side effects and improve the efficacy of treatment. Different strategies have been utilized with nanoparticle drug delivery systems, or nanomedicines, including passive and active targeting strategies, as well as the incorporation of stimuli sensitivity. Additionally, hyperthermia has been used in combination with such systems to further improve accumulation, localization, penetration, and subsequently efficacy. Localized hyperthermia within the solid tumor tissue can be applied through different mechanisms able to trigger vascular and cellular mechanisms for enhanced delivery of nanomedicines. This review covers the use of nanoparticles in drug delivery, the different methods for inducing localized hyperthermia, combination effects of hyperthermia, and successful strategies for improving the delivery of nanomedicines using hyperthermia.

Meta-analysis of endoscopic therapy for low-grade dysplasia in Barrett's oesophagus

Background

The optimal management of patients with Barrett's-associated low-grade dysplasia (LGD) is unclear. The objective of this study was to identify systematically all reports of endoscopic treatment of LGD, and to assess outcomes in terms of disease progression, eradication of dysplasia and intestinal metaplasia, and complication rates.

Methods

A systematic review of articles reporting endoscopic treatment of LGD was conducted in accordance with PRISMA guidelines. MEDLINE and Embase databases were searched to identify the relevant literature. Rates of complete eradication of intestinal metaplasia (CE-IM) and dysplasia (CE-D) were reported. The pooled incidence of progression to cancer was calculated following endoscopic therapy.

Results

Thirty-seven studies met the inclusion criteria, reporting outcomes of endoscopic therapy for 521 patients with LGD. The pooled incidence of progression to cancer was 3·90 (95 per cent confidence interval (c.i.) 1·27 to 9·10) per 1000 patient-years. CE-IM and CE-D were achieved in 67·8 (95 per cent c.i. 50·2 to 81·5) and 88·9 (83·9 to 92·5) per cent of patients respectively. The commonest adverse event was stricture formation.

Conclusion

Reports of endoscopic therapy were heterogeneous and follow-up periods were short. There is a high likelihood of historical overdiagnosis of LGD. Endoscopic therapy, particularly radiofrequency ablation, appears safe and effective at eradicating LGD, but does not eliminate the risk of progression to cancer.

Endoluminal MR-guided ultrasonic applicator embedding cylindrical phased-array transducers and opposed-solenoid detection coil

PURPOSE

MR-guided high-intensity contact ultrasound (HICU) was suggested as an alternative therapy for esophageal and rectal cancer. To offer high-quality MR guidance, two prototypes of receive-only opposed-solenoid coil were integrated with 64-element cylindrical phased-array ultrasound transducers (rectal/esophageal).

METHODS

The design of integrated coils took into account the transducer geometry (360° acoustic window within endoluminal space). The rectal coil was sealed on a plastic support and placed reversibly on the transducer head. The esophageal coil was fully embedded within the transducer head, resulting in one indivisible device. Comparison of integrated versus external coils was performed on a clinical 1.5T scanner.

RESULTS

The integrated coils showed higher sensitivity compared with the standard extracorporeal coil with factors of up to 7.5 (rectal applicator) and 3.3 (esophageal applicator). High-resolution MR images for both anatomy (voxel 0.4 × 0.4 × 5 mm(3)) and thermometry (voxel 0.75 × 0.75 × 8 mm(3), 2 s/image) were acquired in vivo with the rectal endoscopic device. The temperature feedback loop accurately controlled multiple control points over the region of interest.

CONCLUSION

This study showed significant improvement of MR data quality using endoluminal integrated coils versus standard external coil. Inframillimeter spatial resolution and accurate feedback control of MR-guided HICU thermotherapy were achieved.

Advances in endoluminal therapy for esophageal cancer

Advances in endoscopic therapy have resulted in dramatic changes in the way early esophageal cancer is managed as well as in the palliation of dysphagia related to advanced esophageal cancer. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are effective therapies for accurate histopathologic staging and provide a potential for complete cure. Mucosal ablative techniques (radiofrequency ablation and cryotherapy) are effective adjuncts to EMR and ESD and reduce the occurrence of synchronous and metachronous lesions within the Barrett esophagus. The successes of these techniques have made endoscopic therapy the primary means of management of early esophageal cancer.

Endoscopic management of Barrett's esophagus: advances in endoscopic techniques

Barrett's esophagus (BE) is a well-known premalignant condition that can be associated with the development of dysplasia and adenocarcinoma. In the past, esophagectomy was the standard treatment for patients with BE with high grade dysplasia (HGD) and early cancer (EC). However, esophagectomy is not necessarily the only treatment response to HGD and EC anymore. Over the past decade, a number of endoscopic therapies have been developed for management of BE. These include endoscopic mucosal resection, thermal ablation techniques that use laser irradiation, multipolar electrocoagulation, argon plasma coagulation, photodynamic therapy, and the recently developed cryotherapy and radiofrequency ablation.

Endoscopic Resection with Ligation Using a Multi-Band Mucosectomy System in Barrett's Esophagus with High-Grade Dysplasia and Intramucosal Carcinoma

BACKGROUND

Endoscopic therapy for early neoplasia in Barrett's esophagus (BE) is evolving. Endoscopic resection has an increasing role. We wanted to evaluate the safety and efficacy of multi-band ligation/resection [ER-L] without pre-injection in BE with high-grade dysplasia [HGD] and intramucosal carcinoma [IMCA].

METHODS

A cohort of 65 consecutive patients from a single academic medical center, who underwent ER-L as part of endoscopic eradication therapy for BE with HGD/IMCA were studied. ER-L was performed afterendoscopic mapping and endoscopic ultrasound (EUS). Subsequently, adjunctive ablative therapies including photodynamic therapy, argon plasma coagulation and radiofrequency ablation were applied to achieve complete eradication of all BE. Thereafter biopsy surveillance was performed per protocol. All patients were prescribed a proton-pump inhibitor.

MAIN OUTCOME MEASUREMENTS

Change in histopathological stage; eradication of BE and HGD/IMCA; adverse events.

RESULTS

The median number of ER-L applications in each session was 4 (range 1-6) and the mean total number of ER-L sessions was 1.5. Compared with prior forceps biopsy, histopathology from the ER-L specimen changed in 24 (37.5%, p = <0.0001). With median follow-up of 15 months (range 8-42), complete and durable BE eradication was achieved with ER-L alone in 36 (60%) and the remainder with adjunctive ablation therapies. There were nine complications (four (6%) acute bleeding, five (7.5%) strictures, zero perforations).

CONCLUSIONS

ER-L without submucosal (SM) pre-injection is safe and effective when applied selectively for eradication of BE with HGD/IMCA. There is significant change in pathological stage after ER-L conferring a diagnostic and staging advantage. ER-L may be used adjunctively with ablation therapies.

Extensive (8 to 12 cm2) noncircumferential endoscopic mucosal resection for early esophageal cancer

BACKGROUND

Endoscopic mucosal resection (EMR) is an appealing method for treating intramucosal esophageal cancer but must comply with the following stringent requirements: proper preoperative staging, complete resection of the lesion, obtaining a resected specimen for histologic analysis of safety margins, and squamous reepithelialization without stricture formation.

METHODS

A rigid esophagoscope was created to resect up to 12 cm(2) of esophageal mucosa in a single specimen and at a constant depth through the submucosa. Under visual control, the esophageal mucosa is sucked into a transparent window and resected with a thin diathermy wire loop in 10 seconds. After extensive preclinical studies in a sheep model, this article reports our early experience in humans.

RESULTS

Twenty-one hemi-circumferential EMRs were performed for 11 dysplastic Barrett's esophagi and 10 early squamous cell carcinomas with no perforation, one hemorrhage controlled by embolization of the left gastric artery, and one incomplete resection. Deep safety margins were clear in 19 of 21 resected specimens (2 patients, unfit for operations, had submucosal invasion of squamous cell carcinoma and adenocarcinoma, respectively). Lateral margins were not clear by definition in 7 circumferential Barrett's esophagi, but were clear in 4 incomplete Barrett's esophagi and 10 early squamous cell carcinomas.

CONCLUSIONS

Large EMRs of 12 cm(2) can safely be performed at the submucosal level in the esophagus. Although feasible in one session, circumferential EMR in humans is not yet advisable because of the risk of stricture formation during the healing phase. The rate of complications of this series of 21 EMRs in humans is acceptable.

Endoluminal therapy for esophageal disease: an introduction

This introductory article summarizes decades of research from many dedicated gastrointestinal endoscopists. It provides a background to Barrett esophagus (BE), exploring the risk of progression to dysplasia and esophageal adenocarcinoma. Two premalignant conditions, BE and colon adenoma, are compared, including their progression to esophageal adenocarcinoma and colon and rectal carcinoma, respectively. A comparison of the risks of surgical treatment and post-surgical complications of these cancers and of the strikingly different paradigms for their prevention is presented. The article concludes with the rationale for endoscopic treatment of Barrett disease.

An open-label, prospective trial of cryospray ablation for Barrett's esophagus high-grade dysplasia and early esophageal cancer in high-risk patients

BACKGROUND

Endoscopic ablation of Barrett's esophagus (BE) is a treatment option for patients with high-grade dysplasia (HGD) and intramucosal carcinoma (IMCA).

OBJECTIVE

To assess the safety and efficacy of a unique noncontact method of liquid nitrogen cryoablation as measured by histologic response rate and cancer-free survival.

DESIGN

Single-center, nonrandomized cohort study.

SETTING

Referral center, conducted between September 2005 and September 2008.

PATIENTS

Patients with BE and HGD or IMCA who were deemed inoperable or who refused esophagectomy. Age, length of BE, and previous ablation were not exclusion criteria.

INTERVENTION

Cryoablation every 6 weeks until endoscopic resolution. EMR was used for pathologic staging of nodular areas before cryoablation and focal residual areas during the follow-up period.

MAIN OUTCOME MEASUREMENTS

Histologic response was defined by the worst pathology obtained at any level of the esophagus or gastric cardia in 1 of 3 categories: (1) incremental = absence of HGD and IMCA in all biopsy specimens, (2) partial = residual IMCA with absence of any dysplasia, and (3) complete = absence of any intestinal metaplasia or dysplasia.

RESULTS

Thirty patients underwent ablation; 9 had undergone previous ablation or mucosectomy. Twenty-seven of 30 patients (90%) had downgrading of pathology stage after treatment. Elimination of cancer or downgrading of HGD at last follow-up was 68% for HGD and 80.0% for IMCA, with a median follow-up period of 12 months (25th percentile, 6; 75th percentile, 24). Minor adverse events included mild pain (n = 7), a low incidence of mild strictures (n = 3), and lip ulcer (n = 1). One major adverse event (perforation) in a patient with Marfan syndrome occurred with the prototype system. During follow-up, 3 of 6 patients with complete response had recurrence of dysplasia or cancer in the gastric cardia.

LIMITATIONS

A nonrandomized, single-center study with a heterogeneous cohort of patients.

CONCLUSIONS

Patients with BE and HGD or IMCA have a positive response to endoscopic cryotherapy at 1-year follow-up.

Cost effectiveness of ulcerative colitis surveillance in the setting of 5-aminosalicylates

OBJECTIVES

Colorectal cancer (CRC) is a feared complication of chronic ulcerative colitis (UC). Annual endoscopic surveillance is recommended for the detection of early neoplasia. 5-Aminosalicylates (5-ASAs) may prevent some UC-associated CRC. Therefore, in patients prescribed 5-ASAs for maintenance of remission, annual surveillance might be overly burdensome and inefficient. We aimed to determine the ideal frequency of surveillance in patients with UC maintained on 5-ASAs.

METHODS

We performed systematic reviews of the literature, and created a Markov computer model simulating a cohort of 35-year-old men with chronic UC, followed until the age of 90 years. Twenty-two strategies were modeled: natural history (no 5-ASA or surveillance), surveillance without 5-ASA at intervals of 1-10 years, 5-ASA plus surveillance every 1-10 years, and 5-ASA alone. The primary outcome was the ideal interval of surveillance in the setting of 5-ASA maintenance, assuming a third-party payer was willing to pay $100,000 for each quality-adjusted life-year (QALY) gained.

RESULTS

In the natural history strategy, the CRC incidence was 30%. Without 5-ASA, annual surveillance was the ideal strategy, preventing 89% of CRC and costing $69,100 per QALY gained compared with surveillance every 2 years. 5-ASA alone prevented 49% of CRC. In the setting of 5-ASA, surveillance every 3 years was ideal, preventing 87% of CRC. 5-ASA with surveillance every 2 years cost an additional $147,500 per QALY gained, and 5-ASA with annual surveillance cost nearly $1 million additional per QALY gained compared with every 2 years. In Monte Carlo simulations, surveillance every 2 years or less often was ideal in 95% of simulations.

CONCLUSIONS

If 5-ASA is efficacious chemoprevention for UC-associated CRC, endoscopic surveillance might be safely performed every 2 years or less often. Such practice could decrease burdens to patients and on endoscopic resources with a minimal decrease in quality-adjusted length of life, because 5-ASA with annual surveillance may cost nearly $1 million per additional QALY gained.

A histologically defined subset of high-grade dysplasia in Barrett mucosa is predictive of associated carcinoma

To ascertain the prevalence of carcinoma in esophagi resected for high-grade dysplasia (HGD) using current criteria and to evaluate histologic features that may predict concurrent carcinoma, we studied specimens from 127 esophagectomies performed for HGD, or HGD "suspicious" for carcinoma (HGD/S) in Barrett mucosa. Corresponding biopsy specimens in 69 cases were reviewed and reclassified. Based on original diagnoses, carcinoma was present in 15 (17%) of 89 HGD and 28 (74%) of 38 HGD/S cases. By reclassification, only 1 (5%) of 21 cases with HGD had carcinoma in the resection specimen. Of 25 cases reclassified as HGD/S, 18 (72%) had carcinoma in the resection specimen, as did 17 (74%) of 23 reclassified as adenocarcinoma. With 1 additional select histologic feature, the risk of carcinoma was 39%; with 2 or more features, the risk increased to 83% to 88%. Based on current criteria, no more than 5% of esophagectomies performed for a biopsy diagnosis of Barrett HGD harbor carcinoma. When HGD/S is diagnosed based on certain additional features, carcinoma is found in nearly 40% of cases with 1 feature and more than 80% with 2 or more features. Our findings highlight the evolution of diagnostic criteria for Barrett dysplasia.

Mucosal ablation of Barrett esophagus

The management of Barrett esophagus is evolving with the emergence of new endoscopic technologies. Traditionally, patients with high-grade dysplasia or cancer were referred for esophagectomy. However, with the advent of endoscopic ablative therapies for Barrett esophagus, the treatment paradigm has shifted. Patients with high-grade dysplasia and intramucosal carcinoma are increasingly offered esophagus-sparing therapies. Endoscopic ablative therapies can be categorized into tissue-acquiring and non-tissue-acquiring modalities. Visible lesions in the setting of dysplasia should be treated with a tissue-acquiring modality to stage and resect the lesion appropriately. One or more modalities may be used to eradicate the entire region of affected esophagus totally. Total eradication treats all of the at-risk epithelium and, therefore, treats any metachronous or synchronous lesions. Success of treatment may be gauged by complete remission of cancer, dysplasia, or Barrett esophagus. In addition to procedure-related complications, the risk of residual Barrett esophagus or subsquamous Barrett esophagus remains to be addressed. Endoscopic surveillance and acid suppression is still currently required after ablation.

Esophageal adenocarcinoma in Barrett's esophagus after endoscopic ablative therapy: a meta-analysis and systematic review

OBJECTIVES

The extent of reduction of esophageal adenocarcinoma (EAC) incidence in Barrett's esophagus (BE) patients after endoscopic ablation is not known. The objective of this study was to determine the cancer incidence in BE patients after ablative therapy and compare these rates to cohort studies of BE patients not undergoing ablation.

METHODS

A MEDLINE search of the literature on the natural history and ablative modalities in BE patients was performed. Patients with nondysplastic BE (NDBE), low-grade dysplasia (LGD), or high-grade dysplasia (HGD) and follow-up of at least 6 months were included. The rate of cancer in patients undergoing ablation and from the natural history data was calculated using weighted-average incidence rates (WIR).

RESULTS

A total of 53 articles met the inclusion criteria for the natural history data. Pooled natural history data showed cancer incidence of 5.98/1,000 patient-years (95% CI 5.05-6.91) in NDBE; 16.98/1,000 patient-years (95% CI 13.1-20.85) in LGD; and 65.8/1,000 patient-years (95% CI 49.7-81.8) in HGD patients. A total of 65 articles met the inclusion criteria for BE patients undergoing ablation (1,457 patients, NDBE; 239 patients, LGD; and 611 patients, HGD). The WIR for cancer was 1.63/1,000 patient-years (95% CI 0.07-3.34) for NDBE; 1.58/1,000 patient-years (95% CI 0.66-3.84) for LGD; and 16.76/1,000 patient-years (95% CI 10.6-22.9) for HGD patients.

CONCLUSIONS

Compared to historical reports of the natural history of BE, ablation may be associated with a reduction in cancer incidence, although such a comparison is limited by likely heterogeneity between treatment and natural history studies. The greatest benefit of ablation was observed in BE patients with HGD.

Squamous overgrowth is not a safety concern for photodynamic therapy for Barrett's esophagus with high-grade dysplasia

BACKGROUND & AIMS

Photodynamic therapy with porfimer sodium combined with acid suppression (PHOPDT) is used to treat patients with Barrett's esophagus (BE) with high-grade dysplasia (HGD). A 5-year phase 3 trial was conducted to determine the extent of squamous overgrowth of BE with HGD after PHOPDT.

METHODS

Squamous overgrowth was compared in patients with BE with HGD randomly assigned (2:1) to receive PHOPDT (n=138) or 20 mg omeprazole twice daily (n=70). Patients underwent 4-quadrant jumbo esophageal biopsies every 2 cm throughout the pretreatment length of BE until 4 consecutive quarterly follow-up results were negative for HGD and then biannually up to 5 years or treatment failure. Endoscopies were reviewed by blinded gastroenterology pathologists.

RESULTS

Histologic assessment of 33,658 biopsies showed no significant difference (P> .05) in squamous overgrowth between groups when compared per patient (30% vs 33%) or per biopsy (0.5% vs 1.3%), or when the average number of biopsies with squamous overgrowth were compared per patient (0.48 vs 0.66). The highest grade of neoplasia per endoscopy was not found exclusively beneath squamous mucosa in any patient.

CONCLUSIONS

No difference was observed in squamous overgrowth between patients given PHOPDT plus omeprazole compared with only omeprazole. Squamous overgrowth did not obscure the most advanced neoplasia in any patient. Treatment of HGD with PHOPDT in patients with BE does not present a long-term risk of failure to detect subsquamous dysplasia or carcinoma.

Endoscopic ablation of Barrett's esophagus: a multicenter study with 2.5-year follow-up

BACKGROUND

For patients with Barrett's esophagus (BE), life-long surveillance endoscopy is recommended because of an elevated risk for developing dysplasia and esophageal adenocarcinoma. Various endoscopic therapies have been used to eradicate BE. Recently circumferential radiofrequency ablation has been used with encouraging short-term results.

OBJECTIVE

To provide longer follow-up and to assess the long-term safety and efficacy of step-wise circumferential ablation with the addition of focal ablation for BE.

DESIGN

Prospective, multicenter clinical trial (NCT00489268).

SETTING

Eight U.S. centers, between May 2004 and February 2007.

PATIENTS

Seventy subjects with 2 to 6 cm of BE and histologic evidence of intestinal metaplasia (IM).

INTERVENTIONS

Circumferential ablation was performed at baseline and repeated at 4 months if there was residual IM. Follow-up biopsy specimens were obtained at 1, 3, 6, 12, and 30 months. Specimens were reviewed by a central pathology board. Focal ablation was performed after the 12-month follow-up for histological evidence of IM at the 12-month biopsy (absolute indication) or endoscopic appearance suggestive of columnar-lined esophagus (relative indication). Subjects received esomeprazole for control of esophageal reflux.

MAIN OUTCOME MEASUREMENTS

Complete absence of IM per patient from biopsy specimens obtained at 12 and 30 months, defined as complete remission-IM (CR-IM).

RESULTS

At 12 months, CR-IM was achieved in 48 of 69 available patients (70% per protocol [PP], 69% intention to treat [ITT]). At 30 months after additional focal ablative therapy, CR-IM was achieved in 60 of 61 available patients (98% PP, 97% ITT). There were no strictures or buried glandular mucosa detected by the standardized biopsy protocol at 12 or 30 months, and there were no serious adverse events.

LIMITATIONS

This was an uncontrolled clinical trial with 2.5-year follow-up.

CONCLUSION

Stepwise circumferential and focal ablation resulted in complete eradication of IM in 98% of patients at 2.5-year follow-up.

Early Barrett's carcinoma with "low-risk" submucosal invasion: long-term results of endoscopic resection with a curative intent

BACKGROUND

Endoscopic therapy (ET) has become a less risky alternative to open surgery in mucosal Barrett's cancer (BC) because of the very low risk of lymph node (LN) metastasis. Recently published surgical series demonstrated that even in case of minimal submucosal invasion of BC, the risk for LN metastasis is very low. In consequence, also these patients might be eligible for curative ET. The aim of this study was to prospectively evaluate the efficacy and safety of endoscopic resection (ER) in these patients.

METHODS

From September 1996 to September 2003, the suspicion or definite diagnosis of submucosal BC was made in 80 patients referred to our department. Of those, 21 patients (20 male [95.2%], mean age 62 +/- 9 yr, range 47-78) fulfilled the definition of "low-risk" submucosal cancer: invasion of the upper submucosal third (sm1), absence of infiltration into lymph vessels/veins, histological grade G1/2, and macroscopic type I/II. ET was carried out using ER with the suck-and-cut technique with or without an additive ablation of non-neoplastic remnants of Barrett's esophagus.

RESULTS

One of the 21 patients was referred to surgery directly after the detection of sm1 invasion at the beginning of the study. One patient died (not tumor-related) before completion of ET. Using definitive ET, complete remission (CR) was achieved in 18 of 19 patients (95%) after a mean of 5.3 months (range 1-18) and a mean of 2.9 resections (range 1-9). Only one minor complication (bleeding without drop in hemoglobin level >2 g/dL) occurred (5% of patients). During a mean follow-up (FU) of 62 months (range 45-89), recurrent or metachronous carcinomas were found in 5 patients (28%). Repeat ET was carried out successfully using ER (4 patients) and argon plasma coagulation (1 patient). In one of the 19 patients (5%), tumor freedom had not been achieved after a total of 2 ER. This patient died of a heart attack before surgery could be performed. The calculated 5-yr survival rate of all 21 patients was 66%. No tumor-related death occurred.

CONCLUSIONS

As in mucosal BC, ER is associated with favorable outcomes even in case of "low-risk" submucosal BC. Further and larger clinical trials are required before a general recommendation for ER as the treatment of choice in "low-risk" submucosal BC can be given.

Barrett's esophagus and the increasing role of endoluminal therapy

Barrett's esophagus, or the presence of specialized intestinal mucosa in the esophagus that has a malignant potential, has experienced a rapid increase in diagnosis and prevalence over the past few decades. Once thought to progress to adenocarcinoma in an orderly sequence of increasing dysplasia, recent data suggest the process can be more random. In combination with targeted surveillance endoscopy, recent improvements in technology have aided endoluminal therapy in becoming a cost-effective adjunct to medication. When used in combination, in particular, these ablative therapies have become suitable, if not preferable, alternatives to surgery in many patients.

Endoscopic approaches to Barrett's oesophagus with high-grade dysplasia/early mucosal cancer

This chapter will review the endoscopic approaches to the management of Barrett's oesophagus with high-grade dysplasia/early mucosal cancer. Factors to consider when evaluating patients for endoscopic management are detailed. Ablation and resection methods for eradication of Barrett's oesophagus with high-grade dysplasia/early mucosal cancer are reviewed. Strategies for combining therapies to achieve safe and effective eradication are discussed. Recommendations for complete eradication of all Barrett's mucosa and follow-up considerations are put forward.

Drug interactions in inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) often require a combination of drugs, some of which are taken for many years, to control their disease. Some of these drugs have potentially serious side effects, which may be initiated or exacerbated by interaction with other agents used to treat IBD. Furthermore, patients with IBD may take treatment for other, unrelated conditions. It is important for doctors who manage patients with IBD to be aware of, and thereby minimize, the dangers presented by such drug interactions. In this review, we summarize the common and important interactions of drugs used in patients with IBD, including some that may be of therapeutic benefit. Particular attention is paid to interactions that occur where both drugs are used to treat IBD.

Five-year efficacy and safety of photodynamic therapy with Photofrin in Barrett's high-grade dysplasia

BACKGROUND

Barrett's esophagus (BE) with high-grade dysplasia (HGD) is a risk factor for development of esophageal carcinoma. Photodynamic therapy (PDT) with Photofrin (PHO) has been used to eliminate HGD in BE.

OBJECTIVE

Our purpose was to compare PHOPDT plus omeprazole with omeprazole only (OM).

DESIGN

Five-year follow-up of a randomized, multicenter, multinational, pathology-blinded HGD trial.

SETTING

30 sites in 4 countries.

PATIENTS

208.

INTERVENTIONS

Patients with BE and HGD were randomized (2:1) to PHOPDT (n=138) or OM (n=70) into a 2-year trial followed up for 3 more years. PHOPDT patients received 2 mg/kg PHO intravenously followed by endoscopic laser light exposure of Barrett's mucosa at a wavelength of 630 nm within 40 to 50 hours to a maximum of 3 courses at least 90 days apart. Both groups received 20 mg of OM twice daily. Pathologists at one center assessed biopsy specimens in a blinded fashion.

MAIN OUTCOME MEASUREMENT

HGD ablation status over 5 years of follow-up.

RESULTS

At 5 years PHOPDT was significantly more effective than OM in eliminating HGD (77% [106/138] vs 39% [27/70], P<.0001). A secondary outcome measure preventing progression to cancer showed a significant difference (P=.027) with about half the likelihood of cancer occurring in PHOPDT (21/138 [15%]) compared with OM (20/70 [29%]), with a significantly (P=.004) longer time to progression to cancer favoring PHOPDT.

LIMITATIONS

Not all patients were available for follow-up.

CONCLUSIONS

This 5-year randomized trial of BE patients with HGD demonstrates that PHOPDT is a clinically and statistically effective therapy in producing long-term ablation of HGD and reducing the potential impact of cancer compared with OM.

Endoscopic therapy of dysplasia and early-stage cancers of the esophagus

Endoscopic treatments have become a viable alternative for some patients with early-stage esophageal neoplasia. Although esophagectomy remains the standard of care for high-grade dysplasia and superficial cancers, surgical morbidity and mortality may deter patients who are medically unfit or reluctant to undergo surgery. Photodynamic therapy (PDT) and endoscopic mucosal resection (EMR) are the best-studied nonsurgical approaches at present. PDT has been reported to eradicate high-grade dysplasia (HGD) and early Barrett's cancers at rates ranging from 75% to 100% and 17% to 100%, respectively, and a recent randomized controlled trial confirmed that PDT may prevent progression of HGD to cancer. Complete remission rates greater than 90% have also been reported with EMR and other mucosa-ablating interventions, although recurrence rates necessitate close endoscopic surveillance and retreatment in some patients. In addition to PDT and EMR, several emerging endoscopic treatment options for superficial esophageal neoplasia may provide attractive alternatives to surgery.

Endoscopic endoluminal radiofrequency ablation of Barrett's esophagus in patients with fundoplications

BACKGROUND

Endoscopic endoluminal radiofrequency ablation using the Barrx device is a new technique to treat Barrett's esophagus. This procedure has been used in patients who have not had antireflux surgery. This report is presents an early experience of the effects of endoluminal ablation on the reflux symptoms and completeness of ablation in post-fundoplication patients.

METHODS

Seven patients who have had either a laparoscopic or open Nissen fundoplication and Barrett's esophagus underwent endoscopic endoluminal ablation of the Barrett's metaplasia using the Barrx device (Barrx Medical, Sunnyvale, CA). Preprocedure, none of the patients had significant symptoms related to gastroesophageal reflux disease. One to two weeks after the ablation, patients were questioned as to the presence of symptoms. Preprocedure and postprocedure, they completed the GERD-HRQL symptom severity questionnaire (best possible score, 0; worst possible score, 50). Patients had follow-up endoscopy to assess completeness of ablation 3 months after the original treatment.

RESULTS

All patients completed the ablation without complications. No patients reported recurrence of their GERD symptoms. The median preprocedure total GERD-HRQL score was 2, compared to a median postprocedure score of 1. One patient had residual Barrett's metaplasia at 3 months follow-up, requiring re-ablation.

CONCLUSIONS

This preliminary report of a small number of patients demonstrates that endoscopic endoluminal ablation of Barrett's metaplasia using the Barrx device is safe and effective in patients who have already undergone antireflux surgery. There appears to be no disruption in the fundoplication or recurrence of GERD-related symptoms. Nevertheless, longer-term follow-up with more patients is needed.

Balloon-based, circumferential, endoscopic radiofrequency ablation of Barrett's esophagus: 1-year follow-up of 100 patients

OBJECTIVE

To assess the dose-response, safety, and efficacy of circumferential endoscopic ablation of Barrett's esophagus (BE) by using an endoscopic balloon-based ablation device (HALO360 System).

DESIGN

This study was conducted in 2 serial phases (dosimetry phase and effectiveness phase) to evaluate a balloon-based ablation device that delivers a pre-set amount of energy density (J/cm2) to BE tissue. The dosimetry phase evaluated the dose-response and the safety of delivering 6 to 12 J/cm2. The effectiveness phase used 10 J/cm2 (delivered twice [x2]) for all patients, followed by EGD with biopsies at 1, 3, 6, and 12 months. A second ablation procedure was performed if BE was present at 1 or 3 months. Patients received esomeprazole 40 mg twice a day for 1 month after ablation, and 40 mg every day thereafter. Postablation symptoms were quantified by using a 14-day symptom diary (scale, 0-100). A complete response (CR) was defined as all biopsy specimens negative for BE at 12 months.

SETTING

Eight U.S. centers, between September 2003 and September 2005.

PATIENTS

Patients were 18 to 75 years of age, with a diagnosis of BE (without dysplasia), with histopathology reconfirmation of the diagnosis within 6 months of enrollment.

RESULTS

In the dosimetry phase, 32 patients (29 men; mean age, 56.8 years) were enrolled. Median symptom scores returned to a score of 0 of 100 by day 3. There were no dose-related serious adverse events, and the outcomes at 1 and 3 months permitted the selection of 10 J/cm2 (x2) for the subsequent effectiveness phase of the study. In the effectiveness phase, 70 patients (52 men, 18 women; mean age, 55.7 years) were enrolled. Median symptom scores returned to a score of 0 of 100 by day 4. At 12 months (n = 69; mean, 1.5 sessions), a CR for BE was achieved in 70% of patients. There were no strictures and no buried glandular mucosa in either study phase (4306 biopsy fragments evaluated).

CONCLUSIONS

Circumferential ablation of nondysplastic BE by using this balloon-based ablation device can be performed with no subsequent strictures or buried glands and with complete elimination of BE in 70% of patients at 1-year follow-up.

Endoluminal therapy for Barrett's esophagus

This article reviews methods to minimize the complications associated with endoscopic therapy for patients with Barrett's esophagus. To place this discussion in context, the natural history of Barrett's esophagus and the risks associated with progression to dysplasia and invasive carcinoma are reviewed. Operative esophageal resection traditionally is recommended for patients with Barrett's high-grade dysplasia and early carcinoma, and these surgical risks also are reviewed. Finally, all currently approved and commercially available methods for endoscopic ablation and resection of Barrett's disease are categorized according to their application methods of ablation: focal ablation, field ablation, and mucosal resection. The clinical experience with these devices is reviewed with their associated adverse events and complications. Caveats, concerns, and recommendations are discussed to help minimize the complications associated with the use of these important technologies that hold the promise of removing or destroying Barrett's disease to prevent the development of invasive carcinoma.

Ablation of nonneoplastic Barrett's mucosa using argon plasma coagulation with concomitant esomeprazole therapy (APBANEX): a prospective multicenter evaluation

BACKGROUND

Complete reversal of Barrett's epithelium (BE) achieved by treatment with argon plasma coagulation (APC) is variable. The aim of this prospective study was to evaluate the effectiveness of high-power APC in a multicenter trial.

METHODS

In seven study centers, 60 patients (mean age 57, range 27-77) with nonneoplastic BE (length 1-8 cm) were recruited for treatment with high-power APC (90 W) in combination with esomeprazole 80 mg/day. Video endoscopy, chromoendoscopy, and four-quadrant biopsies (4QB) were carried out during baseline endoscopy and regular intervals. The effect of ablation was classified as complete remission (CR), partial remission, or minor response.

RESULTS

Fifty-one of the 60 patients completed ablation therapy. Three patients were lost to follow-up (FU). After a mean of 2.6 APC sessions (range 1-5) and a mean FU of 14 months (range 12-32), CR was achieved in 37 of 48 patients (77%). Major complications occurred in five of 51 patients (9.8%).

CONCLUSIONS

Complete ablation of BE can be achieved in a high percentage of patients even in a multicenter design using high-power APC. However, APC has a relevant morbidity. Therefore, ablation of nonneoplastic BE cannot be recommended generally because incidence of cancer in BE is low.

Endoprevention of esophageal cancer: endoscopic ablation of Barrett's metaplasia and dysplasia

This review describes the use of endoscopic therapy for the treatment of Barrett's disease and the prevention of esophageal carcinoma, predominantly a disease of older white men. While the term endoprevention may be novel, gastroenterologists have been using endoscopic techniques to prevent colon cancer for decades. For the endoprevention of Barrett's carcinoma, the regulatory approval for the use of porfimer sodium photodynamic therapy was an important milestone, as this treatment has been proven to safely ablate Barrett's glandular epithelium, including high-grade dysplasia, and significantly decrease the risk for the development of invasive cancer in several single-center studies, a prospective multicenter randomized controlled study using expert centralized histopathology analysis and long-term single-center results. Newer methods of mucosal ablation, such as the radiofrequency balloon, have been developed for the treatment of patients with Barrett's metaplasia or dysplasia. These newly developed techniques are able to treat large fields of glandular epithelium in a short treatment procedure using safe, effective, durable methods for the complete ablation of Barrett's metaplasia and low-grade dysplasia. These techniques may finally allow the interventional gastrointestinal endoscopist to prevent the development of esophageal carcinoma, just as colonoscopy with polypectomy has prevented colon cancer. However, it will be critically important to document the safety, durability and efficacy of these devices. Ultimately, the impact of successful Barrett's ablation on the incidence of Barrett's carcinoma, and the need for postablation surveillance endoscopy must be determined.

The endoscopic diagnosis and staging of oesophageal adenocarcinoma

The endoscopic evaluation of patients with oesophageal adenocarcinoma does not only serve the purpose of diagnosing the lesion and obtaining biopsies for histological evaluation: a systematic description of advanced lesions is also required to guide further therapeutic decisions. New endoscopic imaging modalities hold the promise of better endoscopic detection of early cancer and its precursor lesions in Barrett's oesophagus. Video-autofluorescence and narrow band imaging are the most promising techniques in this respect. The former may be used as a 'red flag' technique, identifying lesions that remain occult with white light endoscopy; the latter may be used as a targeted imaging technique, allowing for detailed inspection of the mucosal and vascular patterns that may help to distinguish early neoplasia from non-dysplastic tissue. Currently, prototypes are under investigation that combine high-resolution endoscopy, narrow band imaging and video-autofluorescence in one endoscopy system. Endoscopic ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumour infiltration of oesophageal adenocarcinoma and locoregional lymph nodes status. EUS allows for the identification of patients with advanced disease who are unlikely to benefit from attempts at curative surgery and in whom a conservative palliative treatment is indicated. EUS may also play a role in the selection of patients for local endoscopic treatment of early oesophageal cancer. EUS guided fine needle aspiration (EUS-FNA) of locoregional lymph nodes is safe with a high sensitivity and an impeccable specificity for assessment of malignant involvement. The indications for EUS-FNA of lymph nodes, however, depend on local treatment protocols: caeliac nodes (M1a) and lymph nodes located at or above the subcarinal area are the most widely used indications. In addition, it may be important if the choice for specific treatment protocols (e.g. neoadjuvant chemoradiotherapy) depends on lymph node status.

Can clinical and endoscopic findings accurately predict early-stage adenocarcinoma?

BACKGROUND

The presentation and management of esophageal cancer are changing, as more patients are diagnosed at an earlier stage of the disease in which endoscopic treatment methods may be contemplated. Therefore, we conducted a study to determine whether symptomatic and endoscopic findings can accurately identify node-negative early-stage adenocarcinoma.

METHODS

A total of 213 consecutive patients (171 men and 42 women) with resectable esophageal adenocarcinoma seen from 1992 to 2002 were evaluated. None of these patients received neoadjuvant chemotherapy or radiation therapy. Using a multivariable model, model-based probabilities of early-stage disease (T1 im/sm N0) were calculated for each combination of the following three features: no dysphagia as main symptom at presentation, tumor length <or=2 cm, and noncircumferential lesion.

RESULTS

Eighty-two percent of the patients with all three characteristics presented with early-stage disease. Even in the setting of small, visible, noncircumferential tumors/nodules in patients without dysphagia, 14% of the patients harbored node metastasis.

CONCLUSIONS

Simple clinical and endoscopic findings predicted early-stage disease in 82% of cases, whereas a small but significant percentage had node metastasis. Because node metastasis predisposes to local failure in nonresectional treatment options such as endoscopic mucosal resection and photodynamic therapy, such findings should have a significant bearing on treatment decisions.

Photodynamic therapy with porfimer sodium for ablation of high-grade dysplasia in Barrett's esophagus: international, partially blinded, randomized phase III trial

BACKGROUND

Barrett's esophagus (BE) may lead to high-grade dysplasia (HGD) and adenocarcinoma. The objective was to examine the impact of treating patients with BE and with HGD by using porfimer sodium (POR) and photodynamic therapy (PDT) for ablating HGD and reducing the incidence of esophageal adenocarcinoma.

METHODS

The design was a multicenter, partially blinded (pathology), randomized clinical trial conducted in patients with BE who have HGD. There were 30 contributing centers. A total of 485 patients were screened, with 208 in the intent-to-treat population and 202 in the safety population. Patients were randomized on a 2:1 basis to compare PDT with POR plus omeprazole (PORPDT) with omeprazole only (OM). The main outcome measurement was complete HGD ablation occurring at any time during the study period.

RESULTS

There was a significant difference (p < 0.0001) in favor of PORPDT (106/138 [77%]) compared with OM (27/70 [39%]) in complete ablation of HGD at any time during the study period. The occurrence of adenocarcinoma in the PORPDT group (13%) (n=18) was significantly lower (p < 0.006) compared with the OM group (28%) [corrected] (n=20). The safety profile showed 94% of patients in the PORPDT group and 13% of patients in the OM group had treatment-related adverse effects. The limitations of the study were that PDT therapy may have had to be applied more than once and that patients spent more time in treatment. The patients and the physicians were not blinded to the treatment.

CONCLUSIONS

PORPDT in conjunction with omeprazole is an effective therapy for ablating HGD in patients with BE and in reducing the incidence of esophageal adenocarcinoma.

Endoscopic therapy for Barrett's esophagus

With the increase in the rate of esophageal adenocarcinoma in the United States and the Western world matched with the high morbidity and mortality of esophagectomy, there is an increasing need for new and effective techniques to treat and prevent esophageal adenocarcinoma. A wide variety of endoscopic mucosal ablative techniques have been developed for early esophageal neoplasia. However, long-term control of neoplasic risk has not been demonstrated. Most studies show that specialized intestinal metaplasia may persist underneath neo-squamous mucosa, posing a risk for subsequent neoplastic progression. In this article we review current published literature on endoscopic therapies for the management of Barrett's esophagus.

Technology Insight: ablative techniques for Barrett's esophagus—current and emerging trends

New mucosal ablative techniques that can be used in the esophagus have emerged over the past two decades. These techniques have been developed primarily to treat the precursors of esophageal adenocarcinoma: dysplasia in Barrett's esophagus and early esophageal cancer. Although high-grade dysplasia and early stage cancer can be treated with esophagectomy, the inherent morbidity and mortality of esophageal adenocarcinoma and the morbidities, difficulties, costs and limitations of the current technology mean that there has been a significant increase in interest and research regarding alternative treatments such as ablative techniques. At this stage it is not clear which of the numerous endoscopic ablative techniques available-photodynamic therapy, laser therapy, multipolar electrocoagulation, argon plasma coagulation, endoscopic mucosal resection, radiofrequency ablation or cryotherapy-will emerge as superior. In addition, it has yet to be determined whether the risks associated with ablation therapy are less than the risk of Barrett's esophagus progressing to cancer. Whether ablation therapy eliminates or significantly reduces the risk of cancer, eliminates the need for surveillance endoscopy, or is cost-effective, also remains to be seen. Comparative trials that are now underway should help to answer these questions.

Visible endoscopic and histologic changes in the cardia, before and after complete Barrett's esophagus ablation

BACKGROUND

Adverse events associated with the thermal ablation of Barrett's esophagus (BE) include the generation of gastric mucosa buried beneath the neosquamous regrowth, and unrecognized development and growth of adenocarcinomas. No reports exist regarding the endoscopic appearance and histology of the cardia before and after BE ablation. The aim of our study was to assess the relative frequency of the occurrence of visible endoscopic and histologic changes in the cardia, before and after complete BE ablation.

METHODS

A subset analysis of patients with uncomplicated BE, BE with dysplasia, or early carcinoma, who had been enrolled into one of 4 ongoing prospective studies of mucosal ablation, was examined. Eighty-two patients were identified who entered a BE ablation study, with 75 of these completing BE mucosal ablation. Cardia biopsy specimens were taken in all patients before ablation and serially after BE ablation. Cardia histology was graded by using the modified Sydney System for gastritis.

RESULTS

Before ablation, cardia nodules were noted in 3, cardia intestinal metaplasia (IM) in 7 (8.5%), and none harbored cardia dysplasia. Postablation surveillance ranged from 3 to 75 months (mean 31.1 months [19.5]). Six subjects (8%) developed cardia nodules during surveillance; cardia IM was found in 21(28%), with 17 of these being a new finding (incidence of 25%). Cardia low-grade dysplasia incidence was 1.3% and high-grade dysplasia was 4% after BE ablation.

CONCLUSIONS

The pathophysiology of the abnormal cardia histology and the endoscopic lesions (nodules) is unclear, but endoscopic surveillance of not only the neosquamous epithelium but also the cardia should be considered after ablation, especially in those high-grade dysplasia and early adenocarcinoma BE patients.

High-grade dysplasia in Barrett's oesophagus: natural history and review of clinical practice

BACKGROUND

Management of high-grade dysplasia in Barrett's oesophagus is controversial: surgery carries an appreciable morbidity/mortality, high-grade dysplasia may not progress to cancer and endoscopic ablation is an emerging option.

AIM

To review Barrett's oesophagus-related high-grade dysplasia management and outcome over a 10-year period.

METHODS

This was a retrospective case note review of 36 patients identified from a pathology database.

RESULTS

There were 31 men of mean age 67 years. Endoscopic surveillance identified nine. Median follow-up was 21 months. Seven patients had no further intervention because of age/comorbidity. The other 29 had repeat endoscopic biopsies, nine showing cancer (six oesophagectomized). Of the 20 remaining patients with persisting high-grade dysplasia, eight had surgery (histology showed cancer in six), seven continued endoscopic surveillance (high-grade dysplasia regressed in four) and five had 'curative' argon ablation. An intensive biopsy protocol was not followed in 55% of endoscopies. Prevalent cancers occurred in 44% with an annual incidence of 5% over 5 years. All cause mortality was 39% (14 of 36, eight of 14 from cancer).

CONCLUSIONS

Management of high-grade dysplasia was not uniform. Unsuspected cancer was common in high-grade dysplasia patients undergoing surgery but 13% regressed under surveillance. High-grade dysplasia patients have a high mortality but 43% did not die from cancer.

Long-term follow-up after complete ablation of Barrett’s esophagus with argon plasma coagulation

AIM: To report the long-term outcome of patients after complete ablation of non-neoplastic Barrett’s esophagus (BE) with respect to BE relapse and development of intraepithelial neoplasia or esophageal adenocarcinoma.

METHODS: In 70 patients with histologically proven non-neoplastic BE, complete BE ablation was achieved by argon plasma coagulation (APC) and high-dose proton pump inhibitor therapy (120 mg omeprazole daily). Sixty-six patients (94.4%) underwent further surveillance endoscopy. At each surveillance endoscopy four-quadrant biopsies were taken from the neo-squamous epithelium at 2 cm intervals depending on the pre-treatment length of BE mucosa beginning at the neo-Z-line, and from any endoscopically suspicious lesion.

RESULTS: The median follow-up of 66 patients was 51 mo (range 9-85 mo) giving a total of 280.5 patient years. A mean of 6 biopsies were taken during surveillance endoscopies. In 13 patients (19.7%) tongues or islands suspicious for BE were found during endoscopy. In 8 of these patients (12.1%) non-neoplastic BE relapse was confirmed histologically giving a histological relapse rate of 3% per year. In none of the patients, intraepithelial neoplasia nor an esophageal adenocarcinoma was detected. Logistic regression analysis identified endoscopic detection of islands or tongues as the only positive predictor of BE relapse (P = 0.0004).

CONCLUSION: The long-term relapse rate of non-neoplastic BE following complete ablation with high-power APC is low (3% per year).

Novel endoscopic therapies for gastrointestinal malignancies: endoscopic mucosal resection and endoscopic ablation

Gastrointestinal malignancies are often detected at advanced stages when the prognosis is poor. Screening guidelines that vary accord-ing to the regional disease prevalence are needed. High-resolution endoscopy, magnification endoscopy, chromoendoscopy, light autofluorescence endoscopy, and optical coherence tomography are new technologies designed to improve endoscopic detection. Once detected, lesions must be accurately staged, including depth of mucosal penetration and lymph node involvement, to determine endoscopic resectability. Widely applicable, relatively safe, and minimally invasive alternatives to surgery are needed. Endoscopic mucosal resection and endoscopic ablation are potentially curative for malignancies limited to the mucosa, obviating the need for surgery in these patients.