Current status of photodynamic therapy of Barrett's esophagus

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.

The role of photodynamic therapy for hilar cholangiocarcinoma

The prognosis for hilar cholangiocarcinoma is limited by tumor spread along the biliary tree leading to refractory obstructive cholestasis, cholangitis, and liver failure. Palliation with biliary endoprostheses results in median survival times of 4-6 months for advanced bile duct cancer. Photodynamic therapy (PDT) is a local photochemical tumor treatment consisting of a photosensitizing agent combined with laser irradiation of a distinct wavelength. Tumor ablation with PDT combined with biliary stenting reduces cholestasis and significantly improves median survival time. However, the treatment is not widely available, and the photosensitizers used for PDT cause prolonged photosensitivity. Optimum control of tumor spread along the bile ducts and control of cholestasis and cholangitis will prolong survival in one to two thirds of patients, and renders them suitable for other antitumor therapies.

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 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.

Novel endoscopic therapeutic modalities for superficial neoplasms arising in Barrett's esophagus: a primer for surgical pathologists

This review introduces some of the novel endoscopic modalities used for the treatment of superficial neoplasms arising in the setting of Barrett's esophagus, namely endoscopic mucosal resection and photodynamic therapy. We describe the appropriate technical details for pathologists to know to effectively communicate with the gastroenterologists as well as the pitfalls in the evaluation of endoscopic mucosal resection specimens and post photodynamic therapy follow-up biopsies.

Buried Dysplasia and Early Adenocarcinoma Arising in Barrett Esophagus After Porfimer-photodynamic Therapy

The restoration of squamous epithelium after photodynamic therapy (PDT) for Barrett esophagus (BE) and its related neoplasms has been noted. It may result in the development of buried neoplasms and/or BE underneath restored squamous epithelium which maintain their potential for malignant transformation. The purpose of this study was to evaluate the prevalence, endoscopic, and histologic characteristics and also response to further treatment of buried neoplastic epithelium developing after PDT. Fifty-two BE patients with high-grade dysplasia (n=19), intramucosal adenocarcinoma (n=28), and invasive adenocarcinoma (n=5) were treated with porfimer PDT. Buried neoplasms completely covered by squamous epithelium were seen in 1 patient before and in 13 patients after PDT. Their prevalence was 0.6% and 7.4% of pre and post-PDT biopsy levels positive for neoplasia (P=0.001). Buried neoplasms, representing the highest grade of residual neoplasm, were noted in a series of 11 post-PDT endoscopies (7.1% of 155 post-PDT endoscopies with neoplastic diagnoses) of 8 patients. Their occurrence after PDT was neither associated with the length of BE, the diffuseness of neoplasms nor the presence of buried lesions before treatment. There was no prevalent location for these lesions in relation to the original segment of BE, although the majority of both surface and buried neoplasms were found in the prior neoplastic sites. Patients with buried neoplasms responded to further treatment similarly to those with only surface neoplasms (8 of 13 vs. 17 of 24) (P=0.33). In conclusion, buried neoplasms are not uncommon after PDT. Thorough endoscopic surveillance with extensive biopsies, especially of the sites previously positive for neoplasia is important to avoid overlooking buried neoplasms that may progress.

Predictors of stricture formation after photodynamic therapy for high-grade dysplasia in Barrett's esophagus

BACKGROUND

Stricture formation is the leading cause of long-term morbidity after photodynamic therapy (PDT). Risk factors for stricture formation have not been studied.

OBJECTIVE

To assess risk factors for stricture formation in patients undergoing PDT for Barrett's esophagus with high-grade dysplasia (HGD).

DESIGN

Retrospective cohort study.

SETTING

Barrett's Unit, Mayo Clinic, Rochester, Minnesota.

METHODS

Records of patients undergoing PDT for HGD were reviewed. Patients underwent PDT by using either bare cylindrical diffusing fibers (2.5-5.0 cm in length) or balloon diffusers with 5- to 7-cm windows. Univariate and multivariate logistic regression analyses were performed to assess risk factors for stricture formation.

MAIN OUTCOME MEASUREMENT

Esophageal stricture formation.

RESULTS

Thirty-five of 131 patients (27%) developed strictures. On multivariate analysis, statistically significant predictors of stricture formation were the following: EMR before PDT was odds ratio (OR) 2.7, 95% confidence interval (CI) 1.13-6.59; a prior history of esophageal stricture was OR 2.7, 95% CI 1.15-6.47; and the number of PDT applications was OR 2.2, 95% CI 1.22-4.12. The OR for stricture formation in patients when centering balloons were used was 0.41, 95% CI 0.11-1.46, P = .168, indicating that centering balloons did not significantly decrease the risk of stricture formation.

LIMITATIONS

Retrospective single-center study; small proportion of patients treated with centering balloons.

CONCLUSIONS

Risk factors for development of strictures after PDT included history of a prior esophageal stricture, performance of EMR before PDT, and more than 1 PDT application in 1 treatment session. The use of centering balloons was not associated with a statistically significant reduction in the risk of stricture formation.

Predictors of stricture formation after photodynamic therapy for high-grade dysplasia in Barrett's esophagus

BACKGROUND

Stricture formation is the leading cause of long-term morbidity after photodynamic therapy (PDT). Risk factors for stricture formation have not been studied.

OBJECTIVE

To assess risk factors for stricture formation in patients undergoing PDT for Barrett's esophagus with high-grade dysplasia (HGD).

DESIGN

Retrospective cohort study.

SETTING

Barrett's Unit, Mayo Clinic, Rochester, Minnesota.

METHODS

Records of patients undergoing PDT for HGD were reviewed. Patients underwent PDT by using either bare cylindrical diffusing fibers (2.5-5.0 cm in length) or balloon diffusers with 5- to 7-cm windows. Univariate and multivariate logistic regression analyses were performed to assess risk factors for stricture formation.

MAIN OUTCOME MEASUREMENT

Esophageal stricture formation.

RESULTS

Thirty-five of 131 patients (27%) developed strictures. On multivariate analysis, statistically significant predictors of stricture formation were the following: EMR before PDT was odds ratio (OR) 2.7, 95% confidence interval (CI) 1.13-6.59; a prior history of esophageal stricture was OR 2.7, 95% CI 1.15-6.47; and the number of PDT applications was OR 2.2, 95% CI 1.22-4.12. The OR for stricture formation in patients when centering balloons were used was 0.41, 95% CI 0.11-1.46, P = .168, indicating that centering balloons did not significantly decrease the risk of stricture formation.

LIMITATIONS

Retrospective single-center study; small proportion of patients treated with centering balloons.

CONCLUSIONS

Risk factors for development of strictures after PDT included history of a prior esophageal stricture, performance of EMR before PDT, and more than 1 PDT application in 1 treatment session. The use of centering balloons was not associated with a statistically significant reduction in the risk of stricture formation.

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.

Porfimer sodium photodynamic therapy for management of Barrett's esophagus with high-grade dysplasia

Porfimer sodium photodynamic therapy (ps-PDT) for Barrett's esophagus is a powerful endoscopic treatment that can eliminate high-grade dysplasia (HGD) and Barrett's mucosa and reduce the risk of development of cancer in these patients. Ps-PDT typically results in destruction of Barrett's esophagus in the majority of the treated area. However, residual small island of Barrett's mucosa may persist after PDT. Therefore, adjuvant thermal ablation should be available during follow-up endoscopies for ablation of residual islands of Barrett's mucosa. PDT should be applied concurrent with effective proton pump inhibitor therapy. This article provides a practical guide for application of porfimer sodium balloon PDT for management of Barrett's esophagus with HGD. Recommendations are provided for patient selection and screening, delivery of PDT to include light dosimetry, methodology for follow-up endoscopies, as well as discussing the potential side effects and complications.

Photodynamic therapy for Barrett's esophagus with high-grade dysplasia

This article describes advances in photodynamic therapy for patients with Barrett's esophagus and high-grade dysplasia-an important, minimally invasive treatment option proven to safely and durably ablate Barrett's dysplasia and prevent carcinoma while preserving the gastroesophageal junction.

Uses of photodynamic therapy in premalignant and malignant lesions of the gastrointestinal tract beyond the esophagus

Much has recently been written regarding the use of photodynamic therapy for the treatment of esophageal carcinoma and dysplastic Barrett's esophagus. This review, however, describes the clinical experience using photodynamic therapy with various photosensitizer agents for the treatment of diseases in other areas of the gut, especially the pancreaticobiliary tract where European studies have established the role of porfimer sodium photodynamic therapy in the management of patients with cholangiocarcinoma.

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.

Emerging endoscopic techniques in oncology

New techniques have expanded the role of endoscopy in the diagnosis, staging, therapy, and palliation of malignancies. Three major areas of emerging technologies--endoscopic ultrasound (EUS), luminal stent technology, and photodynamic therapy (PDT)--are discussed in this article. Although EUS and PDT have been used for more than two decades, they have only recently emerged as established integral methods in the armamentarium of the gastrointestinal endoscopist.

Biologic properties of columnar epithelium underneath reepithelialized squamous mucosa in Barrett's esophagus

Chronic proton pump inhibitor (PPI) therapy may lead to partial regression of Barrett's esophagus (BE), resulting in the development of reepithelialized islands of squamous mucosa that may cover the underlying BE. The purpose of this study was to evaluate the clinical, histologic, and biologic characteristics of BE that is situated underneath squamous islands (BUSI). A total of 97 mucosal biopsies from 44 BE patients with BUSI were evaluated for a variety of histologic features (eg, type of epithelium, anatomic relationship of the underlying glands to the luminal surface, presence of adjacent mucosal glands or ducts, and the presence and degree of dysplasia), and immunostained for Ki-67, cyclin D1, and p53. BUSI was compared with adjacent areas of BE for all parameters. A clinical control group consisting of 50 BE patients without microscopic evidence of BUSI was selected for comparison of clinical and endoscopic features. The study group (34 males, 10 females; mean age, 67 years; mean length of BE, 5.5 cm) consisted of 27 (61%) and 12 (27%) patients on low- and high-dose PPI, respectively. On endoscopy, visible islands of squamous mucosa were noted in only 43% of study group patients (despite the presence of BUSI microscopically in all cases); one island was noted in 2%, multiple islands in 27%, and extensive islands in 14% of patients. The extent of squamous islands was unrelated to PPI dose. The study group was significantly more likely to have endoscopic evidence of extensive squamous islands compared with the control group (P = 0.009). Histologically, 89% of biopsies with BUSI showed intestinal-type, and 11% showed cardia-type, epithelium. Low- and high-grade dysplasia was noted in 4 (4%) and 5 (5%) biopsies, respectively. All patients with dysplasia in BUSI also showed dysplasia in other areas of the esophagus as well. Interestingly, BUSI reached the mucosal surface either by penetrating directly through, or by wrapping around, islands of squamous epithelium, in 68% of biopsies. Twenty-one percent of biopsies showed BUSI adjacent to submucosal glands or ducts. BUSI showed a significantly lower Ki-67 proliferation rate (29% vs. 49%, P < 0.001), and a lower, albeit nonsignificant, degree of cyclin D1 (16% vs. 29%) and p53 (4% vs. 17%) positivity in comparison to adjacent areas of BE. Furthermore, significantly lower proliferation rates were observed in BUSI that did not reveal an opening to the mucosal surface in comparison to foci that did. BUSI is phenotypically similar to typical surface BE but shows less severe proliferative abnormalities, particularly in buried glands that have no detectable connection to the esophageal lumen. Reduced proliferation may be due either to decreased exposure to luminal contents or to disruption of sloughing of surface epithelial cells into the crypt lumen. Prospective studies of large numbers of patients with BUSI will be required to determine the magnitude of its risk of progression to cancer.

Endoscopic treatment of high-grade dysplasia and early stage cancer in Barrett's esophagus

BACKGROUND

The aim of this study was to prospectively evaluate endoscopic resection (ER) combined with photodynamic therapy (PDT) for the treatment of selected patients with early neoplasia in Barrett's esophagus.

METHODS

Patients with Barrett's esophagus and neoplastic lesions <2 cm in diameter and no sign of submucosal infiltration, positive lymph nodes, or distant metastasis underwent diagnostic ER (cap technique). Patients with a T1sm tumor in the resection specimen were referred for surgery; those with a T1m or a less invasive tumor underwent additional endoscopic therapy (ER, PDT, and/or argon plasma coagulation [APC]), or they were followed. PDT was performed with 5-aminolevulinic acid and a light dose of 100 J/cm 2 at lambda = 632 nm.

RESULTS

Thirty-three patients underwent diagnostic ER. Endoscopic treatment was not performed in 5 patients, who underwent surgery (4 T1sm; 1, patient preference). Five patients were immediately entered into a follow-up protocol, and 23 received additional endoscopic treatment (13 additional ER, 19 PDT, 3 APC). Endoscopic treatment was successful in 26/28 patients; no severe complication was observed. During follow-up (median 19 months, range 13-24 months), 5/26 patients had a recurrence of high-grade dysplasia: all were successfully re-treated with ER. At the end of follow-up, 26/33 originally enrolled patients (79%) and 26/28 endoscopically treated patients (93%) were in local remission.

CONCLUSIONS

Endoscopic therapy is safe and effective for selected patients with early stage neoplasia in Barrett's esophagus.

Histopathologic aspects of photodynamic therapy for dysplasia and early adenocarcinoma arising in Barrett's esophagus

The efficacy of photodynamic therapy (PDT) is currently evaluated for the treatment of superficial neoplasms arising in Barrett's esophagus (BE). An accurate assessment of this technique requires the evaluation of biopsies before and after treatment. However, despite the importance of pathology, only a limited number of studies have systematically assessed the mucosal changes after PDT. To evaluate mucosal changes after PDT, and pathologic variables that may impact on the success of this therapy, we analyzed the pre- and post-PDT biopsies of a cohort of patients treated by this modality. Thirty-three patients (mean age, 71 years) with high-grade dysplasia (HGD) and/or intramucosal carcinoma (IMC) arising in BE and followed up after PDT using Porfimer sodium form the basis of this study. In all patients, a review of all pre- and post-PDT biopsies was performed. The variables recorded included the histologic grade and architecture of neoplasms, the distribution of neoplasms, and squamous re-epithelialization. IMC and HGD coexisted in the pre-PDT biopsies of 18 patients (54.5%). IMC and HGD showed a prominent tubular proliferation in 14 patients and displayed a papillary pattern (at least partially) in 19 patients. In post-PDT, patches of specialized columnar epithelium were buried under squamous epithelium in 17 patients (51.5%), and foci of dysplasia/carcinoma covered by squamous epithelium were found in 9 patients (27.3%). HGD and/or IMC were eradicated in 17 patients (eradicated group) and persisted in 16 patients (persistent group). In the persistent group, grade and architecture were unchanged after PDT in 62.5% and 87.5% of patients, respectively. The persistent group was characterized by: 1) a more frequent papillary architecture (P < 0.05), and 2) a diffuse distribution of the neoplasms on pre-PDT biopsies (P = 0.05). Singularly, the persistent neoplastic lesions were observed in the distal esophagus (P < 0.05). A systematic histopathologic evaluation allowed us to draw attention to the fact that distally located and papillary-type neoplasia seem resistant to PDT. The higher than expected incidence of buried residual neoplastic epithelium should also be emphasized since it represents a risk for undetected growth of malignancy.

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).

Photodynamic therapy induced esophageal stricture—an animal model: From mouse to pig

INTRODUCTION

A major limitation of photodynamic therapy (PDT) for Barrett's esophagus is the development of esophageal stricture. We developed an animal model of PDT-induced esophageal stricture to elucidate the mechanism of stricture development. Our studies began in a mouse but, due to its limitations, we advanced to a porcine model.

MATERIALS AND METHODS

In the mouse model, 62 mice were injected with Photofrin (2-10 mg/kg) 48 h prior to photoactivation. Light energy (20-400 Joules/cm (J)) was delivered with a laser probe as a single dose, or fractionated doses (20-150 J). Animals were sacrificed when showing signs of distress or 6 to 18 weeks post-illumination. Esophagus was removed, with gross and microscopic examination performed on frozen specimens. To develop a pig model, six pigs were injected with Photofrin (2 mg/kg) 48 h prior to photoactivation. Light energy (400 J) was delivered via an endoscope using a laser probe as a single dose or repeated at 48 h. Animals were sacrificed if they could not eat soft food or lost more than 10% of their original weight according to the University of Pittsburgh Institutional Animal Care and Use Committee.

RESULTS

Exposure of mice to doses of 400 J x 1, 125 J x 3, or 150 J x 3 fractions resulted in severe lung damage and death in 90% of the mice without any evidence of esophageal stricture. Lower energy levels caused minor lung damage and no change in the endothelial layer or a stricture. In pigs, exposure of 400 J as one or two fractions resulted in weight loss of 10% within 3 weeks. Endoscopy, upper GI, contrast swallow, and pathological and histological examination showed evidence of esophageal stricture at the exposed area.

CONCLUSIONS

In the mouse model, pulmonary toxicity is the limiting factor following esophageal PDT exposure. In the pig model we induced esophageal stricture following PDT. This is the first animal model created to study esophageal strictures resulting from PDT.

Time-dependent hexaminolaevulinate induced protoporphyrin IX distribution after topical application in patients with cervical intraepithelial neoplasia: A fluorescence microscopy study

BACKGROUND AND OBJECTIVES

Compared to the conventional management of cervical intraepithelial neoplasia (CIN) the potential advantage of photodynamic therapy (PDT) for the treatment of cervical human papilloma virus (HPV)-related disease encompasses a minimal invasive procedure with reduced risk of profuse bleeding as a consequence of conization, and possibly more favorable long-term results avoiding cervical stenosis. At present little is known about the precise time-dependent distribution and histological localization of hexaminolaevulinate (HAL) induced protoporphyrin IX (PPIX) fluorescence in healthy tissue and in CIN. The aim of this study was to use ex vivo fluorescence microscopy to determine whether PPIX is selectively induced by neoplastic cells of the cervical epithelium at various times after topical application.

STUDY DESIGN/MATERIALS AND METHODS

Cold cream containing 0.5% HAL was applied by means of cervical cap over various periods of time. We analyzed 52 healthy cervical mucosa and 84 CINs.

RESULTS

At time delay 100 (+/-10) minutes, high epithelial fluorescence and a significant selectivity between epithelium and underlying lamina propria was found. By contrast, no significant difference between healthy and neoplastic tissues, or between low and high-grade epithelial dysplasia (P > or = 0.05), was observed at any time point.

CONCLUSIONS

Application of HAL 0.5% cream to the cervix induced selective fluorescence in epithelial cells. The optimal ratio with a homogeneous PPIX distribution was obtained after 100 ( +/- 10) minutes cream application, which should be evaluated further for PDT.

Photodynamic therapy with green light and m-tetrahydroxyphenyl chlorin for intramucosal adenocarcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND

The eradication of early stage neoplastic lesions in Barrett's esophagus is imperative to prevent invasive adenocarcinoma. Early stage lesions have an extremely low risk of lymph node metastasis, thereby, making local treatment feasible. Photodynamic therapy destroys malignant cells by a photochemical effect. The aims of this study were to evaluate the efficacy and tolerance of photodynamic therapy with green light and a new photosensitizer, temoporfin or m-tetrahydroxyphenyl chlorin in patients with Barrett's esophagus and early stage neoplastic lesions.

METHODS

Four days after injection of m-tetrahydroxyphenyl chlorin, lesions were illuminated at a wavelength of 514 nm through non-circumferential windowed diffusers. Follow-up endoscopy with biopsies was performed at regular intervals.

RESULTS

Fourteen lesions (7 high-grade dysplasia, 7 intramucosal adenocarcinoma) in 12 patients were treated. For all lesions, efficacy was 100% and squamous re-epithelialization was complete. Side effects were of moderate severity (one stricture). Mean follow-up was 34 (15) months (range 12-68 months).

CONCLUSIONS

Green light photodynamic therapy with m-tetrahydroxyphenyl chlorin can eradicate early stage neoplastic lesions in Barrett's esophagus and may be proposed as an alternative first-line therapy or a second-line therapy after failure of other endoscopic treatments. The efficacy and patient tolerance of the procedure justify further studies of the method in larger groups of patients.

High-Energy Laser Therapy of Barrett’s Esophagus: Preliminary Results

We present the preliminary results obtained by our research group utilizing Nd:YAG and diode lasers to treat Barrett's esophagus (BE). A total of 15 patients with BE (mean age 58 years) underwent endoscopic laser therapy: 11 with intestinal metaplasia, 2 with low-grade dysplasia, and 2 with high-grade dysplasia. The mean length of BE was 4 cm (range 1-12 cm). Six of these patients also underwent antireflux surgery, and nine were prescribed acid-suppressive medication. Endoscopic Nd:YAG laser treatment was carried out from 1997 to 1999; thereafter, diode laser was employed. The mean follow-up of these patients after the first laser session was 28 months. Patients underwent a mean of 6.5 laser sessions (range 3-17 sessions), with no apparent complications. The mean energy per session was 1705 JJ. Only six of these patients (40%) showed complete endoscopic and histologic remission, but a mean of 77% (SD 23.8%) of the total metaplastic tissue in all these patients was ablated. The percentage of healed mucosa was higher in patients with short-segment BE (92%) ( p < 0.05) and in subjects treated by two or more laser sessions per centimeter of BE length (89%) ( p < 0.05). All four patients with dysplasia showed histologic regression to nondysplastic BE or to squamous epithelium, without recurrence during a mean follow-up of 30 months. The patients who underwent antireflux surgery and those prescribed pharmacologic treatment had similar results. Nd:YAG and diode laser treatment of BE is a safe, effective procedure; it required two sessions per centimeter of metaplasia; and it achieved complete regression of the dysplasia. Further studies are necessary to quantify its effect on cancer incidence.

Use of lasers in Barrett's esophagus

Lasers are used in the management of Barrett's esophagus for specific tasks. First is for the ablation of non-dysplastic and dysplastic Barrett's as part of an aggressive, minimally invasive, yet unproven preventive interventional strategy for both low-risk and high-risk of progression subgroups. Secondly is for potentially curative treatment of early mucosal cancers (Tis and T1mN0M0). Finally, lasers are used for palliation of dysphagia for advanced tumors. The first two laser uses should be considered experimental and undertaken in the setting of an institutionally approved research protocol. Paramount to the success of ablation of dysplastic and early cancerous Barrett's is careful selection of patients by meticulous video endoscopic inspection of the mucosa, use of high frequency and dedicated endosonography (to uncover unsuspected tumors that penetrate the submucosa or involve lymph nodes that cannot be targeted by laser treatment), and experienced GI pathologists. Lasers can also play an important adjuvant role in the management of dysphagia for advanced cancers: however, the specific patients' characteristics for this group of patients is currently not well-defined in this era of easily placed expandable metallic stents.

Mucosal ablation with photodynamic therapy in the esophagus: optimization of light dosimetry in the sheep model

BACKGROUND

Photodynamic therapy is an attractive technique for mucosal ablation in patients with superficial squamous cell carcinoma of the esophagus, or high-grade dysplasia or early stage adenocarcinoma arising in Barrett's esophagus. Although illumination with green light is assumed to be safe, choice of the light has been empirical in clinical studies; light dose is often reduced to avoid potential complications. The present study assessed the safety of green and blue lights during photodynamic therapy in the esophagus by progressively administrating increasing doses in an attempt to standardize the dose and determine a safe upper limit. This would considerably simplify photodynamic therapy and improve therapeutic results.

METHODS

The sheep model was chosen because of similarities with humans regarding the thickness and histologic structure of the esophagus. Irradiation with a 180 degrees windowed cylindrical light distributor was performed in 19 sheep 4 days after injection of 0.15 mg/kg of tetra(m-hydroxyphenyl) chlorin. Light doses ranged from 10 to 500 J/cm(2) at 514 nm (argon ion laser) and from 5 to 250 J/cm(2) at 413 nm (krypton laser).

RESULTS

Follow-up endoscopies revealed a tissue response with a fibrinous area at almost all light doses, whereas application of extremely high light doses tended to induce circumferential necrosis with subsequent stenosis. Three months after irradiation with green light, histologic examination of the resected specimens revealed transmural scarring at doses higher than 100 J/cm(2). After illumination with blue light, partial or more extensive fibrosis of the muscular layer was observed only at light doses of 175 to 250 J/cm(2).

CONCLUSIONS

Application of high doses of green light after sensitization with tetra(m-hydroxyphenyl) chlorin led to severe complications in the esophagus of the sheep that are highly likely to occur in humans as well. Blue light causes significantly less damage than green light and may, therefore, be considered as an alternative for photodynamic therapy of early stage superficial esophageal cancer.

Intracellular Localization is a Cofactor for the Phototoxicity of Protoporphyrin IX in the Gastrointestinal Tract: In Vitro Study¶†

Photodynamic therapy (PDT) is a new treatment modality for solid tumors as well as for flat lesions of the gastrointestinal tract. Although the use of 5-aminolevulinic acid-induced protoporphyrin IX (PPIX) shows important advantages over other photosensitizers, the main mechanisms of phototoxicity induced are still poorly understood. Three human colon carcinoma cell lines with variable degrees of differentiation and a normal colon fibroblast cell line were used to generate a suitable in vitro model for investigation of photosensitizer concentration as well as the applied light dose. Also, the effects of intracellular photosensitizer localization on efficiency of PDT were examined, and cellular parameters after PDT (morphology, mitochondrial transmembrane potential, membrane integrity and DNA fragmentation) were analyzed to distinguish between PDT-induced apoptosis from necrosis. The fibroblast cell line was less affected by phototoxicity than the tumor cells to a variable degree. Well-differentiated tumor cells showed higher toxicity than less-differentiated cells. After irradiation, cell lines with cytosolic or mitochondrial PPIX localization indicate a loss of mitochondrial transmembrane potential resulting in growth arrest, whereas membrane-bound PPIX induces a loss of membrane integrity and consequent necrosis. Although the absolute amount of intracellular photosensitizer concentration plays the main determining role for PDT efficiency, data indicate that intracellular localization has additional effects on the mode of cell damage.

Neodymium:yttrium-aluminum garnet contact laser ablation of Barrett's high grade dysplasia and early adenocarcinoma

OBJECTIVES

We describe the efficacy and safety of neodymium:yttrium-aluminum garnet (Nd:YAG) contact laser ablation of Barrett's high grade dysplasia (HGD) and/or early adenocarcinoma.

METHODS

Consecutive Barrett's patients in whom HGD or adenocarcinoma was detected were eligible. Radial array echoendosonography and high frequency catheter probe ultrasonography were performed. Patients were excluded if ultrasound revealed the presence of Barrett's cancer with regional lymph nodes or celiac trunk metastases or extension of the tumor into superficial submucosa (T1sm1) or greater. Nd:YAG laser used quartz contact probes, with all Barrett's epithelium targeted at each session. Complete ablation was confirmed with Lugol's iodine chromoendoscopy followed by surveillance biopsies of the neosquamous epithelium. Adverse events were ascertained by scheduled telephone contact interviews.

RESULTS

A total of 36 patients with HGD/adenocarcinoma were evaluated at our center, 17 of whom met all inclusion criteria. Of the patients, 14 have remained in the study, and all have had successful elimination of HGD and cancer. In addition, 11 patients (78.6%) achieved complete endoscopic and histological ablation of all Barrett's tissue. Two patients (14.3%) achieved 95% destruction of Barrett's with residual metaplastic columnar epithelium containing goblet cells without dysplasia. The remaining patient has obtained 75% ablation of Barrett's, with residual metaplastic columnar epithelium harboring Barrett's with low grade dysplasia. Major complications included two esophageal strictures (11.8%) and one mild upper GI bleed (5.9%).

CONCLUSIONS

This preliminary experience with Nd:YAG contact laser for the treatment of Barrett's HGD and early superficial cancers seems promising. The need for additional controlled trials with larger numbers of patients with longer follow-up, as well as consideration of a head-to-head trial with Photofrin photodynamic therapy, is warranted.

Photodynamic therapy for dysplastic Barrett esophagus and early esophageal adenocarcinoma

OBJECTIVE

To evaluate our results using photodynamic therapy (PDT) for the treatment of dysplasia or superficial cancer (T1 N0 M0) in patients with Barrett esophagus.

PATIENTS AND METHODS

We retrospectively reviewed our clinical experience with 48 patients (34 patients with high-grade dysplasia and 14 patients with superficial cancer in Barrett esophagus) who had been referred for PDT. Initial evaluation included computed tomography and standard and high-frequency catheter endosonography. Follow-up endoscopy was performed 4 to 6 weeks after PDT with ablation of any residual glandular mucosa, using the argon plasma coagulator. Patients were then followed up indefinitely every 3 to 6 months with computed tomography, endosonography, and endoscopic surveillance.

RESULTS

The median series follow-up was 18.5 months (range, 1-56 months). Apparent complete photoablation of Barrett mucosa and/or superficial neoplasm was documented in 47 of 48 cases. Complications included symptomatic strictures (11 patients), photosensitivity (7 patients), atrial fibrillation (1 patient) or recurrent congestive heart failure (1 patient), and self-limited esophageal perforation (1 patient). Failure to ablate T1 N0 M0 adenocarcinoma occurred in 1 patient.

CONCLUSIONS

Porfimer sodium PDT appears to eradicate dysplastic Barrett mucosa and neoplasia. These results are promising; however, long-term studies are needed to document the efficacy of PDT in reducing the morbidity and mortality in such patients.

Fluorescence endoscopy and photodynamic therapy

Fluorescence endoscopy is a new technique which allows a better detection of non-visible malignant or premalignant lesions or, those which are difficult to detect. Exogenously applied sensitisers accumulate selectively in malignant lesions and induce fluorescence after illumination with light of adequate wavelength. However, also endogenous fluorophores, different located in malignant or benign lesions, induce a different autofluorescence in these lesions. Tissue fluorescence can be detected by optical sampling of the mucosa using fluorescence spectroscopy or by generating real time fluorescence images with specialised camera systems. Compared to point fluorescence spectroscopy the latter technique enables the screening of large surface areas of mucosa. Meanwhile, fluorescence endoscopy is a widely used technique in urology employing 5-aminolaevulinic acid sensitisation. In gastroenterology, this technique seems promising for the detection of early cancers or dysplasia in patients with Barrett's oesophagus or ulcerative colitis. Using different sensitisers, photodynamic therapy seems to be a promising option for patients with advanced oesophageal cancer and in the palliative treatment of non-resectable bile duct cancer, furthermore for patients with early gastric cancer and dysplasia in Barrett's oesophagus. Probably, by laser light fractionation or a combination of different sensitisers, an enhanced effect can be expected.

Mucosal ablation in Barrett's esophagus

Barrett's esophagus is a prevalent, premalignant condition affecting the gastroesophageal junction and distal esophagus. Ablation plus antireflux therapy has recently been advocated to prevent the development of adenocarcinoma or to treat those unfit or unwilling to undergo esophagectomy. The present article, based on a search of Medline/ISI databases and cross-referencing of relevant articles, reviews the literature on this subject. A number of techniques have been used to remove the affected mucosa, including laser, electrocoagulation, argon plasma coagulation and photodynamic therapy but, as yet, none has been shown to be superior. Depending on the method used, ablation results in complete removal of Barrett's esophagus in approximately one third of patients and a partial response in nearly two-thirds. The resultant squamous mucosa is apparently 'normal' but may regress. To promote and maintain regeneration, antireflux therapy must be sufficient to reduce repetitive injury to the esophageal mucosa. Whether ablation reduces the cancer risk or delays its occurrence is unknown, though recent data suggests benefit. Complications are infrequent and usually mild. Regular follow-up endoscopy and deep biopsies continue to be necessary. Careful data from much larger populations with long-term follow-up is required before ablation reaches the stage of broad clinical application.

Management of Barrett's esophagus with high-grade dysplasia

About 38% to 73% of patients diagnosed with BE with HGD and who went on to have an esophagectomy already had esophageal ACA. The low 5-year survival rate of invasive esophageal ACA places pressure on the physician to find a way to prevent or to remove the cancer. Endoscopic ablative therapies have been developed, but these new technologies are to be considered as a secondary option. Although there are many recent improvements in surveillance strategies and endoscopic ablative therapies, series are small and follow-up is short. These modalities do show promise and may be a good option in the future for patients who are poor surgical candidates. At the present time, the standard of care for BE with HGD in good surgical candidates is still esophagectomy.

Barrett's esophagus: surveillance and treatment

Barrett's esophagus is a disease of paramount importance dictated by its exponentially increasing incidence and association with esophageal cancer. Unfortunately, our knowledge lacks much of the key data and information to make those important decisions in Barrett's as regards screening and treatment. With an evident lack of long-term large population studies of patients with Barrett's esophagus, much of our decision making is based on little available data and becomes somewhat arbitrary. Given these limitations, screening criteria include adults with a long history of persistent reflux symptoms. The precise age, frequency, and duration of symptoms used is unclear. Once Barrett's is identified, endoscopic surveillance is performed every 2 years, but this interval will most likely lengthen to 3 years. For patients with LGD, surveillance every 6-12 months is recommended. For HGD, esophagectomy is still recommended for healthy surgical candidates, but more patients will be followed, particularly those with "focal" HGD. The role of acid suppression either pharmacologically or surgically is not clear, but the tendency is to achieve near complete control of the acid reflux. Endoscopic ablative procedures are experimental and may be indicated in patients at high surgical risk with HGD and carcinoma. Its role in mainstream practice is yet to be defined.

Nonsurgical management of Barrett's esophagus with high-grade dysplasia

Endoscopic management options for BE with high-grade dysplasia consist of either surveillance methods or endoscopic mucosal ablative therapies. Intensive surveillance once a person is diagnosed with high-grade dysplasia may avoid an unneeded esophagectomy because it appears that most patients with high-grade dysplasia may not progress to esophageal adenocarcinoma. Only a single study has been presented that demonstrates that this approach does not lead to missed opportunities for intervention before progression to advanced stage disease [20]. This study excluded patients with cancer detected within 1 year of diagnosis of high-grade dysplasia; thus, patients who wish to proceed with an observation approach should be aware that the rate of missed esophageal adenocarcinomas ranges from 38% to 73%. The ability to observe a patient with high-grade dysplasia, however, does have appeal because a number of these patients appear to lose the high-grade dysplasia over time. The other endoscopic management option for Barrett's esophagus with high-grade dysplasia is endoscopic mucosal ablative therapies. These include the KTP:YAG laser, the Nd:YAG laser, photodynamic therapy, and endoscopic mucosal resection. All ablative therapies are used in combination with control of gastroesophageal reflux. This allows the esophageal tissue to heal in an environment that is conducive to squamous mucosa. Although most are relatively small series with short durations of observation, they all have shown some promise in treating BE with high-grade dysplasia. These approaches have the advantage of eliminating the problem. The patient who is being observed must live with the thought of developing cancer. Patients who undergo successful ablation are returned to a normal life. The combination of therapies such as EMR with PDT may be the most promising approach to BE with high-grade dysplasia; however, the long-term effects of ablative therapy are not known and continued surveillance is still advised for this group of patients. The choice of a nonsurgical approach for the management of BE with high-grade dysplasia is ultimately up to the individual patient. All patients must be carefully informed of the treatment effects, possible outcomes, and the surgical alternative. Most patients who select nonsurgical approaches are either elderly or are not good surgical candidates. The choice is often affected by local expertise, as surgical procedures should be performed in centers with surgeons expert in esophagectomy. Nonsurgical approaches should also be performed by physicians who are familiar with their application. Future advances in nonsurgical techniques such as new photosensitizers in PDT and improvements in diagnostic techniques may allow patients a greater opportunity to preserve their esophagus.

Role of mucosal ablative therapy in the treatment of the columnar-lined esophagus

With the high prevalence of gastroesophageal reflux-like symptoms in the United States and the association between GERD symptoms and the premalignant condition of BE, there is more and more demand for new and efficacious techniques to treat BE. A wide variety of endoscopic mucosal ablative techniques have been developed with promising initial results. Long-term control of neoplastic risk, however, has not been demonstrated, and most studies demonstrate that there is still potentially some intestinal mucosa present underneath squamous mucosa. Currently, more study is needed to determine which patient groups require therapy of any kind and to determine which therapies would be the most efficacious. Genetic markers may aid in identification of subgroups that are at risk for cancer and help to identify those who would respond to mucosal therapy. Even in patients who have HGD, subgroups of patients who have focal HGD have been found to have better prognosis than those who have more widespread HGD. Currently, there is sufficient information to consider mucosal ablative techniques in patients who are not good surgical candidates. Photodynamic therapy, APC, KTP, Nd:YAG and argon lasers, MPEC, and EMR may provide good alternatives, depending on the degree of dysplasia, the extent of disease, and the age of the patient. Photodynamic therapy and Nd:YAG laser therapy have been applied to more neoplastic lesions, whereas KTP:YAG, APC, and multipolar coagulation have been successful in nondysplastic Barrett's mucosa. In the future, there will be more information to justify the application of mucosal ablative therapy in selected patients.

The adoption of ablation therapy for Barrett's esophagus: a cohort study of gastroenterologists

OBJECTIVES

Although ablation therapy may be useful in the treatment of Barrett's esophagus. evidence of effectiveness is scarce, and little is known about current utilization of ablation. We aimed to determine whether the use of ablation was increasing in a cohort of gastroenterologists, and to identify physician beliefs and characteristics associated with ablation use.

METHODS

We surveyed a national sample of gastroenterologists about ablation use, with an 18-month follow-up. The self-administered instrument included questions about demographic characteristics, attitudes about ablation therapy, and prior experience with ablation. Case scenarios were also included. We used logistic regression to identify factors associated with the use of ablation in patients with Barrett's esophagus.

RESULTS

Two hundred seventy-nine (50.3% of those eligible) responded to the baseline survey. Few agreed that ablation lowers the risk of adenocarcinoma (15%) or is supported by the medical literature (19%). However, 25% of respondents reportedly had used ablation at baseline, and this increased to 36% in the follow-up survey (p = 0.0003). The use of ablation was significantly associated with physician age greater than 54 yr (odds ratio [OR] = 2.77, 95% CI = 1.04-7.37) and the belief that ablation was used by colleagues (OR = 13.27, 95% CI = 4.44-39.64) or decreases medical costs (OR = 5.07, 95% CI = 1.00-25.74).

CONCLUSIONS

Although few gastroenterologists agreed that ablation is effective, a significant proportion had adopted its use. There was a significant increase in ablation use during our study period, and the characteristic that was most strongly associated with ablation use was the belief that colleagues used it.

Combined endoscopic mucosal resection and photodynamic therapy for esophageal neoplasia within Barrett's esophagus

BACKGROUND

Endoscopic mucosal resection (EMR) and photodynamic therapy have been proposed as treatments for early stage cancers. EMR is limited by its focal nature whereas photodynamic therapy is dependent on precise staging. The combination of EMR and photodynamic therapy were studied in the treatment of superficial cancer in patients with Barrett's esophagus.

METHODS

Seventeen consecutive nonsurgical patients with superficial cancers underwent EMR followed by photodynamic therapy with a porphyrin photosensitizer. Photoradiation was performed at 630 nm for a total dose of 200 J/cm of diffuser.

RESULTS

Seventeen patients (15 men; mean age 69 +/- 13 years) underwent EMR. The mean diameter of mucosal resection was 1 cm. The margins were involved by cancer in 3 cases. EMR improved staging in 8 patients (47%). Sixteen (94%) patients remained in remission (median follow-up 13 months). Complications included minor bleeding after EMR in 1 patient (6%), stricture in 5 (30%), cutaneous phototoxicity in 2 (12%), and supraventricular tachycardia in 1 patient (6%).

CONCLUSIONS

Combined EMR and photodynamic therapy appears to be an effective and safe therapy for superficial esophageal cancer within Barrett's esophagus. This combination improves cancer staging, removes the superficial cancer, and eliminates remaining mucosa at risk for cancer development.

Use of a simple symptom questionnaire to predict Barrett's esophagus in patients with symptoms of gastroesophageal reflux

OBJECTIVE

Accurately predicting Barrett's esophagus (BE) in patients with gastroesophageal reflux disease (GERD) is difficult. Using logistic regression analysis of symptom questionnaire scores we created a model to predict the presence of BE.

METHODS

We conducted a logistic regression analysis of symptom data collected prospectively on 517 GERD patients and created a prediction model based on patient gender, age, ethnicity, and symptom severity.

RESULTS

There were 337 (65%) males and 180 (35%) females, of whom 99 (19%) had Barrett's esophagus (BE). Multiple logistic regression analysis was performed to determine the predictive ability of gender, age, and ethnicity along with symptoms of heartburn, nocturnal pain, odynophagia, presence of belching, dysphagia, relief of symptoms with food, and nausea. The only significant predictors (at the 0.05 level) were male gender, heartburn, nocturnal pain, and odynophagia (all with positive effects on the presence of BE) and dysphagia (which had a negative effect). A nomogram was produced to show the effect of a given predictor on the probability of having BE in the context of the effects of the other predictors, and to estimate the probability of having BE for a given individual. The mean score (+/-SD) for the BE patients in our sample was 397.4+/-46.2 with a range of 292-530. For the patients without BE, the mean score (+/-SD) was 351.3+/-60.3 with a range of 190 - 528 (p < 0.001). If screening for BE is performed at a score of 375 or more, our model would have a specificity of 63% with a sensitivity of 77% (95% CI 61-86% given the 63% specificity).

CONCLUSIONS

By asking seven questions about symptom severity, clinicians may be able to assign a probability to the presence of BE, and thus, determine the need for endoscopy in GERD patients.

Photodynamic therapy and the alimentary tract

Photodynamic therapy offers the possibility of relatively selective tumour necrosis and normal tissue healing. It has many potential applications but as yet no clear role. Articles, editorials and case reports published primarily in English and listed in Medline/ISI up to April 2000 or identified by a manual search have been reviewed in an attempt to provide a comprehensive overview of the use of photodynamic therapy in the alimentary tract. It is concluded that photodynamic therapy can be an effective treatment for superficial pre-malignant mucosal lesions and early cancers, especially in diffuse disease. Suitable patients include those wishing to avoid surgery, high risk subjects or those in whom other forms of treatment have failed. Superiority over other methods of ablation has not so far been demonstrated. Cheaper and more effective photosensitizers and improved techniques of light delivery are likely to increase the application of photodynamic therapy.

Extent of high-grade dysplasia in Barrett's esophagus correlates with risk of adenocarcinoma

BACKGROUND & AIMS

The identification of any high-grade dysplasia (HGD) in Barrett's esophagus has been considered to be an indication for esophagectomy because of the increased risk of cancer. The aim of this study was to determine if a limited extent of HGD has the same potential for cancer as diffuse HGD.

METHODS

A retrospective cohort study was performed to assess the risk of developing adenocarcinoma in relationship to the extent of HGD found on endoscopic surveillance. The extent of HGD was defined as focal if cytologic and/or architectural changes of HGD were limited to a single focus of 5 or fewer crypts and diffuse if more than 5 crypts were involved in a single biopsy specimen or if HGD involved more than one biopsy fragment. The relative risk of cancer was assessed using a Cox proportional hazard model, and cancer-free survival was determined using survival curves.

RESULTS

Sixty-seven patients with diffuse HGD and 33 with focal HGD satisfied selection criteria. Cancer-free survival rates at 1 and 3 years were 93% and 86% for focal HGD compared with 62% and 44% for diffuse HGD (P < 0.001). On univariate analysis, extent of HGD (relative risk, 5.36; 95% confidence interval, 1.84-15.56), nodularity on endoscopy (relative risk, 3.98; 95% confidence interval, 1.97-8.04), and lack of acid suppression (relative risk, 2.48; 95% confidence interval, 1.16-5.28) were associated with an increased risk of esophageal adenocarcinoma. Diffuse HGD had a 3.7-fold increase in the risk of esophageal cancer compared with focal HGD (P = 0.02) on multivariate analysis.

CONCLUSIONS

Patients with focal HGD are less likely to have cancer during the first year after diagnosis or on subsequent follow-up compared with diffuse HGD.

Mucosal ablation therapy of barrett esophagus

Barrett esophagus is defined by the metaplasia of existing squamous mucosa into a specialized intestinal-type mucosa. The importance of this metaplasia is the association of this condition with the development of adenocarcinoma of the esophagus. Elimination of the metaplastic mucosa may decrease the cancer risk. Currently, several forms of therapy have evolved with the goal of replacing the specialized mucosa with normal squamous mucosa. These proposed treatments include photodynamic therapy and thermal techniques. The effectiveness of photodynamic therapy varies depending on the pharmaceutical photosensitizer used and the wavelength of light applied to activate the drug. Thermal techniques include multipolar coagulation, argon plasma coagulation, KTP:YAG laser therapy, Nd:YAG laser therapy, and argon laser therapy. Finally, mucosal resection has been attempted through the endoscope to remove large areas of the Barrett mucosa. All of these ablative strategies attempt to destroy the metaplastic mucosa and promote the regrowth of squamous epithelium. These therapies have demonstrated the ability to "reverse" the metaplasia to varying degrees, but a decrease in cancer risk has not been demonstrated conclusively with any of these treatment methods.

Optimizing endoscopic biopsy detection of early cancers in Barrett's high-grade dysplasia

OBJECTIVE

The of high-grade dysplasia management (HGD) in Barrett's esophagus remains controversial, in part, because of uncertainty about the ability of endoscopic biopsies to consistently detect early, curable cancers.

METHODS

Here we report cancers we have diagnosed in 45 patients with Barrett's HGD using a protocol involving serial endoscopies with four-quadrant biopsies taken at 1-cm intervals. We compare these results to a modeled endoscopic biopsy protocol in which four-quadrant biopsies are taken every 2 cm in the Barrett's segment.

RESULTS

Thirteen cancers were detected at the baseline endoscopy and 32 in surveillance. In 82% of patients, cancer was detected at a single 1-cm level of the esophagus, and in 69% the cancer was detected in a single endoscopic biopsy specimen. A 2-cm protocol missed 50% of cancers that were detected by a 1-cm protocol in Barrett's segments 2 cm or more without visible lesions. The maximum depth of cancer invasion was intramucosal in 96% of patients. Only 39% of patients who had endoscopic biopsy cancer diagnoses had cancer detected in the esophagectomy specimen. Adverse outcomes included the development of regional metastatic disease during surveillance (1 of 32), operative mortality (3 of 36), including two patients who had their primary surgeries at other institutions, and death from metastatic disease after endoscopic ablation performed at another institution (1 of 3).

CONCLUSIONS

A four-quadrant, 1-cm endoscopic biopsy protocol performed at closely timed intervals consistently detects early cancers arising in HGD in Barrett's esophagus and should be used in patients with HGD who do not undergo surgical resection.