Photodynamic therapy for dysplastic Barrett esophagus and early esophageal adenocarcinoma

Endoscopic ultrasound for esophageal and gastroesophageal junction cancer: Impact of increased use of primary neoadjuvant therapy on preoperative locoregional staging accuracy

Initial treatment of locally advanced esophageal and gastroesophageal junction (GEJ) malignancies for selected patients at some institutions has recently changed from surgical resection to neoadjuvant therapy. The aim of this study is to evaluate the impact of this change in treatment strategy on both the overall disease profile and locoregional endoscopic ultrasound (EUS) staging accuracy for a cohort of patients managed with primary surgical resection over a 10-year period at our institution. All subjects at our institution who underwent primary esophagectomy from 1993 to 2002 following preoperative EUS for known or suspected esophageal and/or GEJ cancers were identified. Patients with dysplasia alone, prior upper gastrointestinal tract surgery, preoperative neoadjuvant therapy, cancer of the gastric cardia or recurrent malignancy were excluded. EUS findings and staging results were compared to surgical pathology following resection. The impact of the gradually increased use of primary chemoradiation during the second half of the study was assessed. Of the 286 operations performed, 184 subjects were excluded. The remaining 102 underwent primary surgical resection a median of 18 days following EUS staging for adenocarcinoma (88%) or squamous cell carcinoma (12%) of the esophagus (69%) or GEJ (31%). Overall EUS locoregional T and N staging accuracy was 72% and 75% respectively; accuracy for T1, T2, T3 and T4 cancer was 42%, 50%, 88% and 50% respectively. Despite an increased frequency of pathologically confirmed T1 and T2 cancers (P = 0.005) and an insignificant trend toward increased N0 malignancy (P = 0.05) during the second half of the study period, no statistically significant changes in T (P = 0.07) or N (P = 0.82) staging accuracies for EUS or disease characteristics were noted between the first and second half of the study period. Despite both inaccurate radial EUS staging and increased relative use of primary surgery for early cancers, recent increased use of primary neoadjuvant therapy did not change overall disease characteristics and accuracy of locoregional EUS staging of esophageal and GEJ cancers managed with primary surgical resection.

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.

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.

Clinical experience of patients undergoing photodynamic therapy for Barrett's dysplasia or cancer

INTRODUCTION

Barrett's oesophagus is the most important risk factor in the increase in incidence of oesophageal adenocarcinoma. Photodynamic therapy using porfimer sodium is the only approved endoscopic treatment for use in patients with Barrett's high-grade dysplasia.

AIM

To determine clinical characteristics, endoscopic findings and treatment complications in Barrett's high-grade dysplasia patients undergoing photodynamic therapy.

METHODS

We reviewed our experience using porfimer sodium photodynamic therapy to treat patients with Barrett's oesophagus and high-grade dysplasia or mucosal carcinoma. Data collected included patients characteristics, presentation symptoms, endoscopic findings, subsequent use of surveillance endoscopy and outcome after photodynamic therapy.

RESULTS

Since 1997, 102 patients with Barrett's high-grade dysplasia (69 patients) or mucosal adenocarcinoma (33 patients) have been treated with photodynamic therapy using porfimer sodium as an alternative to oesophagectomy (median series follow-up time = 1.6 years). Almost half (46%) of patients had high-grade dysplasia or carcinoma detected on their first endoscopy and the remainder (54%) were found during surveillance of known Barrett's oesophagus. Symptoms typically associated with oesophageal disease were only found in 29 of 47 (62%) patients in whom dysplasia/carcinoma was detected on the initial endoscopy - chest pain in 13 patients, dysphagia in nine patients and chronic gastro-oesophageal disease in seven patients. Comparison of endoscopic characteristics found the median Barrett's glandular segment length was significantly shorter in adenocarcinoma patients (median 3 cm; range: 1-12) vs. Barrett's high-grade dysplasia patients (median 5 cm; range: 1-16, P < 0.001). Overall treatment results found complete ablation of glandular epithelium with one course of photodynamic therapy in most patients (56%). Stricture requiring dilation occurred in 20 patients (20%) was the most common serious adverse event. Photodynamic therapy failed to ablate dysplasia or carcinoma in four patients and subsequent oesophagectomy was curative in three of these patients.

CONCLUSIONS

Approximately 40% of newly diagnosed patients with Barrett's associated dysplasia or carcinoma had no oesophageal symptoms and had carcinoma associated with short segment (3 cm or less). Photodynamic therapy is a highly effective, safe and minimally invasive first-line treatment for patients with Barrett's dysplasia and mucosal adenocarcinoma.

Cost-effectiveness of photodynamic therapy for high-grade dysplasia in Barrett's esophagus

BACKGROUND

Photodynamic therapy appears to be effective in ablating high-grade dysplasia in Barrett's esophagus. Our aim was to identify the most effective and cost-effective strategy for managing high-grade dysplasia in Barrett's esophagus without associated endoscopically visible abnormalities.

METHODS

By using decision analysis, the lifetime costs and benefits of 4 strategies for which long-term data exist were estimated by us: esophagectomy, endoscopic surveillance, photodynamic therapy, followed by esophagectomy for residual high-grade dysplasia; and photodynamic therapy followed by endoscopic surveillance for residual high-grade dysplasia. It was assumed by us that there was a 30% prevalence of cancer in high-grade dysplasia patients and a 77% efficacy of photodynamic therapy for high-grade dysplasia and early cancer.

RESULTS

Esophagectomy cost 24,045 dollars, with life expectancy of 11.82 quality-adjusted life years. In comparison, photodynamic therapy followed by surveillance for residual high-grade dysplasia was the most effective strategy, with a quality-adjusted life expectancy of 12.31 quality-adjusted life years, but it also incurred the greatest lifetime cost (47,310 dollars) for an incremental cost-effectiveness of 47,410 dollars/quality-adjusted life years. The results were sensitive to post-surgical quality of life and survival, and to cancer prevalence if photodynamic therapy efficacy for cancer was less than 50%.

CONCLUSIONS

Photodynamic therapy followed by endoscopic surveillance for residual high-grade dysplasia appears to be cost effective compared with esophagectomy for patients diagnosed with high-grade dysplasia in Barrett's esophagus. Clinical trials directly comparing these strategies are warranted.

Photodynamic therapy and endoscopic mucosal resection for Barrett's dysplasia and early esophageal adenocarcinoma

BACKGROUND

Endoscopic mucosal resection (EMR) and endoscopic ablation with porfimer sodium photodynamic therapy (PDT) have recently been combined to improve the accuracy of histologic staging and remove superficial carcinomas.

MATERIALS AND METHODS

All patients with Barrett's esophagus and high-grade dysplasia were evaluated with computed tomography and endosonography. Patients with nodular or irregular folds underwent EMR followed by PDT.

RESULTS

In three patients, endoscopic mucosal resection upstaged the diagnosis to mucosal adenocarcinoma (T1N0M0). PDT successfully ablated the remaining glandular mucosa. Complications were limited to transient chest discomfort and odynophagia.

CONCLUSIONS

The use of EMR resection in Barrett's high-grade dysplasia patients with mucosal irregularities resulted in histologic upstaging to mucosal adenocarcinoma, requiring higher laser light doses for PDT. PDT after EMR appears to be safe and effective for the complete elimination of Barrett's mucosal adenocarcinoma. EMR should be strongly considered for Barrett's dysplasia patients being evaluated for endoscopic ablation therapy.

Recurrent Barrett's esophagus and adenocarcinoma after esophagectomy

Background

Esophagectomy is considered the gold standard for the treatment of high-grade dysplasia in Barrett's esophagus (BE) and for noninvasive adenocarcinoma (ACA) of the distal esophagus. If all of the metaplastic epithelium is removed, the patient is considered "cured". Despite this, BE has been reported in patients who have previously undergone esophagectomy. It is often debated whether this is "new" BE or the result of an esophagectomy that did not include a sufficiently proximal margin. Our aim was to determine if BE recurred in esophagectomy patients where the entire segment of BE had been removed.

Methods

Records were searched for patients who had undergone esophagectomy for cure at our institution. Records were reviewed for surgical, endoscopic, and histopathologic findings. The patients in whom we have endoscopic follow-up are the subjects of this report.

Results

Since 1995, 45 patients have undergone esophagectomy for cure for Barrett's dysplasia or localized ACA. Thirty-six of these 45 patients underwent endoscopy after surgery including 8/45 patients (18%) with recurrent Barrett's metaplasia or neoplasia after curative resection.

Conclusion

Recurrent Barrett's esophagus or adenocarcinoma after esophagectomy was common in our patients who underwent at least one endoscopy after surgery. This appears to represent the development of metachronous disease after complete resection of esophageal disease. Half of these patients have required subsequent treatment thus far, either repeat surgery or photodynamic therapy. These results support the use of endoscopic surveillance in patients who have undergone "curative" esophagectomy for Barrett's dysplasia or localized cancer.

Photodynamic therapy and endoscopic metal stent placement for esophageal papillomatosis associated with squamous cell carcinoma

Esophageal squamous papillomatosis is a rare condition associated with human papilloma virus infection and has been complicated by the development of squamous cell carcinoma. Photodynamic therapy using porfimer sodium has been used for the treatment of esophageal cancer but has not been utilized in the treatment of esophageal squamous papillomatosis. We report here the first case of papillomatosis and obstructing squamous cell carcinoma of the esophagus palliated with porfimer sodium photodynamic therapy indicating successful photosensitizer uptake in papilloma-laden tissue. Extensive debulking of papilloma and tumor allowed esophageal recanalization and placement of a self-expanding metal stent for long-term dysphagia palliation. This unique case highlights the combined use of endoscopic techniques for optimal treatment results.

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.

Barrett's esophagus: management of high-grade dysplasia and cancer

Esophagectomy remains the treatment of choice for the appropriate patient with Barrett's adenocarcinoma invading beyond the mucosa, without evidence of distant metastasis or invasion of adjacent organs. On the other hand, therapeutic management of patients with Barrett's high-grade dysplasia (HGD) or mucosal adenocarcinoma should be individualized, taking into account the patient's preferences, willingness to return for frequent endoscopic biopsies, and medical fitness to undergo esophagectomy. Surgery has to be considered the best treatment for HGD or superficial carcinoma, unless contraindicated by severe comorbidities, because it has proven to be the only treatment that is successful in curing the condition and preventing recurrent HGD or the development of invasive cancer. Nonsurgical treatment by photodynamic therapy or endoscopic mucosal resection may be a less invasive and organ-sparing option for elderly, poor-risk patients but it is still to be considered an investigational therapy that should only be conducted under a clinical trial protocol. Finally, intensive endoscopic biopsy surveillance of patients with HGD is another investigational option that may allow prompt treatment of cancer if it develops. However, few data document the safety of this observational approach.

Optical detection and eradication of dysplastic Barrett's esophagus

Dysplastic Barrett's esophagus is a condition that offers multiple diagnostic and therapeutic challenges. The diagnosis of dysplasia within Barrett's esophagus currently relies on periodic endoscopic surveillance with multiple biopsies, a methodology limited by random sampling error, inconsistent histopathologic interpretation and delay in diagnosis. Optical spectroscopic and imaging techniques have the potential to identify dysplastic or early neoplastic lesions in real-time. These diagnostic modalities are needed to enhance the endoscopic surveillance of Barrett's esophagus in the future as well as help to define lesions for endoscopic therapy. Esophagectomy has been the standard of care for Barrett's esophagus with high-grade dysplasia although it is a procedure associated with significant morbidity and mortality. Minimally invasive endoscopic ablative therapies are attractive and less morbid alternatives to esophagectomy, with promising results obtained from the use of light-activated drugs (i.e., photodynamic therapy). The combination of novel optical diagnostic techniques and therapies will provide the endoscopist with much needed tools that can considerably enhance the management of patients with Barrett's esophagus. This article reviews the current status and future prospects of optical-based modalities for diagnosis and therapy of dysplastic Barrett's esophagus.

Endoscopic therapeutic esophageal interventions: old, new, borrowed and . . . methylene blue?

PURPOSE OF REVIEW

Endoscopic interventions in the esophagus continue to evolve. This article reviews some of the notable advances over the past year in endoscopic therapy for the esophagus.

RECENT FINDINGS

In 2002 several endoscopic therapies were reintroduced or modified. Ablative treatments, including Nd:YAG laser, photodynamic therapy, and thermal contact treatments have been shown to be effective for Barrett esophagus and some early esophageal cancers. The addition of endoscopic mucosal resection may improve these therapies. Endoscopic stenting remains the dominant endoscopic palliative modality for unresectable esophageal cancers, and modifications of this therapy have focused on reducing side effects and complications. Innovations in endoscopic treatments for strictures and bleeding esophageal varices have been proposed and may improve outcomes, although probably only marginally. Additional endoscopic antireflux procedures have been introduced, although the results of long-term studies still need to be published before their place in the treatment of gastroesophageal reflux disease can be determined.

SUMMARY

Rather than heralding novel endoscopic therapeutics, 2002 was a year of retooling and refining existing techniques.

Limited resection for early esophageal cancer?

BACKGROUND

Early squamous cell carcinoma (SCC) and early adenocarcinoma (AC) of the esophagus are potentially curable diseases. The crucial point in treatment is that the depth of tumor infiltration into the mucosal and submucosal layers is correlated with the rate of nodal metastases and therefore with long-term prognosis.

METHODS AND FOCUS

In submucosal SCC with a high rate of nodal metastases curative resection can be achieved only by radical esophagectomy with systematic lymphadenectomy, which remains the treatment of choice for this tumor entity. In submucosal AC the Merendino procedure may offer an alternative since lymphatic invasion occurs at a later stage than in SCC, and locoregional lymph nodes can be adequately resected. Major advantages of this operation over radical esophagectomy include the complete resection of the entire Barrett segment and the lower postoperative morbidity and mortality. Vagal-sparing esophagectomy still lacks adequate oncological evaluation for it to be recommended except in stage I a tumors. For mucosal SCC and AC endoscopic mucosal resection is the treatment of choice but requires intensive follow-up since the rate of complete resections is lower than in limited and radical surgical procedures. On the other hand, a low postoperative morbidity and the functional integrity of the tubular esophagus support the use of endoscopic mucosal resection for mucosal cancer.