Prevention of adenocarcinoma by reversing Barrett's esophagus with mucosal ablation

Photodynamic Therapy for Barrett's Esophagus and Esophageal Carcinoma

This paper reviews the use of photodynamic therapy (PDT) in patients with Barrett's esophagus and esophageal carcinoma. We describe the history of PDT, mechanics, photosensitizers for PDT in patients with esophageal disease. Finally, we discuss its utility and limitations in this setting.

Patient-centered, comparative effectiveness of esophageal cancer screening: protocol for a comparative effectiveness research study to inform guidelines for evidence-based approach to screening and surveillance endoscopy

BACKGROUND

The comparative effectiveness (CE) of endoscopic screening (versus no screening) for Barrett's esophagus (BE) in patients with GERD symptoms, or among different endoscopic surveillance strategies in patients with BE, for the early detection of esophageal adenocarcinoma (EA) is unknown. Furthermore, it is unclear if patients or providers have or will adopt any of these strategies (screening only, screening and surveillance, vs. none), irrespective of their effectiveness. Endoscopic screening and surveillance is expensive and can be risky. Therefore, it is imperative to establish the CE and acceptability about the risks and outcomes related to these practices to better inform expert recommendations and provider-patient decisions.

METHODS/RESULTS

We propose a mixed methods study which will involve: (1) an analysis of secondary databases (VA and VA-Medicare linked datasets for 2004-09) to examine CE of endoscopic screening and surveillance in an observational study cohort (an estimated 680,000 patients with GERD; 25,000-30,000 with BE; and 3,000 with EA); (2) a structured electronic medical record (EMR) review on a national sample of patients using VA EMRs to verify all EA cases, identify cancer stage, cancer-targeted therapy, and validate the screening and surveillance endoscopy; and (3) qualitative in depth interviews with patients and providers to elicit preferences, norms, and behaviors to explain clinical contexts of these findings and address gaps arising from the CE study.

CONCLUSION

This study will compare clinical strategies for detecting and monitoring BE, a pre-cancerous lesion. Additionally, by eliciting acceptability of these strategies for patients and providers, we will be able to propose effective and feasible strategies that are likely to be implemented in routine use. Findings will inform recommendations for clinical practice guidelines. Our innovative approach is consistent with the methodological standards of patient-centered outcomes research, and our findings will offer a significant contribution to the literature on cancer surveillance.

The role of photodynamic therapy in the esophagus

Photodynamic therapy (PDT) is a drug and device therapy using photosensitizer drugs activated by laser light for mucosal ablation. Porfimer sodium PDT has been used extensively with proven long-term efficacy and durability for the ablation of Barrett esophagus and high-grade dysplasia. and early esophageal adenocarcinoma. However, continued use is hampered by an associated stricture risk and prolonged photosensitivity (4-6 weeks). Promising single-center European studies using other forms of PDT, such as aminolevulinic acid PDT, have not been replicated elsewhere, limiting the widespread use of other forms of PDT. Future use of PDT in esophageal disease depends on the development of improved dosimetry and patient selection to optimize treatment outcomes, while minimizing adverse events and complications.

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.

Laparoscopic treatment of Barrett's esophagus: long-term results

BACKGROUND

Gastroesophageal reflux disease (GERD) is considered the main etiologic process in the metaplastic development of Barrett's esophagus (BE). The most serious complication of BE is the possible dysplastic evolution to esophageal carcinoma. Many treatments have been described to prevent the progression of BE. The outcomes of these interventions are controversial. The aim of this study was to assess whether laparoscopic fundoplication for GERD had an impact on the development of BE.

METHODS

Prospective data were collected from patients who were treated with a laparoscopic fundoplication for BE. Data was collected and analyzed for a variety of clinical and pathologic outcomes.

RESULTS

Laparoscopic fundoplications were completed between 1993 and 2001, with a total sample size of 92 (mean age 53 +/- 11.8 years). Each patient was diagnosed with GERD associated with BE confirmed by both endoscopy and biopsy. A laparoscopic fundoplication was performed in all patients (360 degree fundoplication in 81 patients and partial fundoplication in 11 patients). There was no postoperative mortality or major complications from the procedure. The mean postoperative stay was 3 +/- 1 days. Seventy patients (76% of the overall sample size) were followed up for a mean 4.2 +/- 2.6 years. Of the patients available for follow-up, 33% (n = 23) had a complete regression of their BE; 21% (n = 15) had a decrease in the degree of metaplasia/dysplasia; 39% (n = 27) had no significant change; and 7% (n = 5) experienced a progression of the BE. Five patients required further procedures for three reasons: (1) GERD recurrence (n = 2), (2) progression of BE (n = 2), and (3) intrathoracic migration (n = 1). No patients developed high-grade dysplasia or esophageal carcinoma.

CONCLUSIONS

The results of this study suggest that laparoscopic fundoplication offers a safe and effective long-term treatment for BE. The procedure also demonstrated regression of BE in more than 50% of the sample size.

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.

Present status of photodynamic therapy for high-grade dysplasia in Barrett's esophagus

GOALS

Review recent developments in Barrett's dysplasia including regulatory approval of porfimer sodium photodynamic therapy.

BACKGROUND

Barrett's esophagus is thought to be the result of long-standing gastroesophageal reflux disease and is known to be the most important risk factor for the development of esophageal adenocarcinoma. The natural history of Barrett's esophagus is not well known, but the annual incidence of invasive adenocarcinoma is estimated to be 0.5% (reported range, 0.2%-2.0%). This represents an increased risk for esophageal cancer of 30 to 60 times higher than normal subjects. As for colorectal cancer, malignant degeneration is Barrett's esophagus is thought to occur through a continuum of histologic stages: metaplasia, dysplasia and neoplasia. Barrett's high-grade dysplasia (formerly referred to as carcinoma in situ) is the histologic stage of disease that immediately precedes the development of invasive carcinoma.

CONCLUSIONS

Previously, Barrett's high-grade dysplasia patients were routinely referred for esophageal resection surgery based upon the assumption of inevitable progression to cancer, the high rate of undiagnosed synchronous cancers, and few treatment alternatives. Important developments in Barrett's high-grade dysplasia include recent publications regarding the natural history of Barrett's high-grade dysplasia and the regulatory approval for endoscopic ablation therapy using porfimer sodium photodynamic therapy (Photofrin PDT).

Prevention and management of early esophageal cancer

Early esophageal cancer is defined by its limitation to the esophageal mucosa and submucosa. It has become a curable malignant disease, in sharp contrast to the dismal prognosis of esophageal cancer at advanced stages, which still represents the majority of patients. Understanding the risk factors, establishing surveillance programs for patients at risk, and developing preventative interventions such as dietary and lifestyle changes or pharmacologic interventions hold the potential of reducing the incidence of the disease and of shifting the stage distribution toward early cancer. Endoscopic ultrasound examination is pivotal for distinguishing early from advanced stages of the disease because it allows for accurate assessment of tumor infiltration and regional lymph node involvement. The therapeutic mainstay for early esophageal cancer remains surgery. New, less invasive surgical techniques are being tested that are associated with less morbidity and mortality than standard radical esophagectomies. For patients who are not candidates for surgery, definitive chemoradiation is a viable alternative. New endoscopic ablation techniques, such as endoscopic mucosa resection and photodynamic therapy, are potential alternatives to surgery in patients with cancers limited to the mucosa. For patients with adenocarcinoma of the gastroesophageal junction with submucosal involvement, adjuvant chemoradiation should be considered because of its potential to increase survival.