Surveillance in Barrett's oesophagus: a critical reappraisal

A labelled discrete choice experiment adds realism to the choices presented: preferences for surveillance tests for Barrett esophagus

Background

Discrete choice experiments (DCEs) allow systematic assessment of preferences by asking respondents to choose between scenarios. We conducted a labelled discrete choice experiment with realistic choices to investigate patients' trade-offs between the expected health gains and the burden of testing in surveillance of Barrett esophagus (BE).

Methods

Fifteen choice scenarios were selected based on 2 attributes: 1) type of test (endoscopy and two less burdensome fictitious tests), 2) frequency of surveillance. Each test-frequency combination was associated with its own realistic decrease in risk of dying from esophageal adenocarcinoma. A conditional logit model was fitted.

Results

Of 297 eligible patients (155 BE and 142 with non-specific upper GI symptoms), 247 completed the questionnaire (84%). Patients preferred surveillance to no surveillance. Current surveillance schemes of once every 1–2 years were amongst the most preferred alternatives. Higher health gains were preferred over those with lower health gains, except when test frequencies exceeded once a year. For similar health gains, patients preferred video-capsule over saliva swab and least preferred endoscopy.

Conclusion

This first example of a labelled DCE using realistic scenarios in a healthcare context shows that such experiments are feasible. A comparison of labelled and unlabelled designs taking into account setting and research question is recommended.

Should patients with Barrett's oesophagus be kept under surveillance? The case for

Oesophageal adenocarcinoma is associated with high mortality rates and its incidence is increasing more rapidly than any other gastrointestinal cancer in the Western world. Several factors, including gastro-oesophageal reflux disease, smoking, alcohol and male gender, are associated with oesophageal adenocarcinoma but none can be used to identify accurately those individuals who will develop adenocarcinoma. It is generally accepted that oesophageal adenocarcinoma arises predominantly in Barrett's oesophagus and it is arguable that Barrett's oesophagus is currently the only clinically useful predictor of oesophageal adenocarcinoma. Surveillance - periodic testing to detect adenocarcinoma or its precursor, high grade dysplasia - is widely recommended for patients with Barrett's oesophagus with the aim of reducing mortality from oesophageal adenocarcinoma. The annual incidence of oesophageal adenocarcinoma in patients with Barrett's oesophagus is 0.5%-1.0% although there is marked variation between studies, attributable variously to publication bias, concurrent acid suppression therapy and differences in patient characteristics. There is limited evidence that surveillance reduces the incidence of oesophageal adenocarcinoma or consequent mortality and the cause of death for patients undergoing surveillance is often unrelated to oesophageal disease. There are, nonetheless, observational studies which suggest that surveillance is associated with earlier detection of malignancy and a reduction in mortality; in addition, data from modelling studies suggest that surveillance can be cost-effective. Furthermore, the advent of new, non-surgical treatments (endoscopic mucosal resection, photodynamic therapy, argon plasma coagulation) for high grade dysplasia and early cancer has reduced the risks associated with therapy for disease detected during surveillance. Surveillance programs have high drop out rates and, for patients who continue surveillance, adherence to standard, published protocols is highly variable. The establishment of specialist Barrett's oesophagus surveillance programs, with coordinator support, has considerable potential to improve adherence to current guidelines, pending the acquisition and publication of data from ongoing studies of chemoprophylaxis and surveillance in the management of Barrett's oesophagus. In consequence, although there is a paucity of data providing unequivocal demonstration of benefit, there is no proof that surveillance is ineffective. It is, therefore, appropriate to offer surveillance for Barrett's oesophagus in accordance with locally-applicable published guidelines after a full informed discussion of the risks and benefits of surveillance and therapy; continued participation should be reviewed regularly to accommodate changes in the patient's health and expectations.

Different perceptions of the burden of upper GI endoscopy: an empirical study in three patient groups

Background

Few studies have evaluated patients’ perceived burden of cancer surveillance tests. Cancer screening and surveillance, however, require a large number of patients to undergo potentially burdensome tests with only some experiencing health gains from it. We investigated the determinants of patients’ reported burden of upper gastrointestinal (GI) endoscopy by comparing data from three patient groups.

Patients and methods

A total of 476 patients were included: 180 patients under regular surveillance for Barrett esophagus (BE), a premalignant disorder; 214 patients with non-specific upper GI symptoms (NS), and 82 patients recently diagnosed with upper GI cancer (CA). We assessed pain, discomfort and overall burden experienced during endoscopy, symptoms in the week afterwards and psychological distress over time (Hospital Anxiety and Depression scale and Impact of Event Scale).

Results

Two-thirds (66%) of patients reported discomfort and overall burden of upper GI endoscopy. Only 23% reported any pain. BE patients reported significantly less discomfort, pain and overall burden than the other patients: those with NS reported more discomfort, CA patients more pain, and both more overall burden. These differences could be statistically explained by the number of previous endoscopies and whether sedation was provided or not, but not by patient characteristics.

Conclusion

The perception of upper GI endoscopy varies by patient group, due to potential adaptation after multiple endoscopies and aspects of the procedure.

Patients with Barrett's esophagus perceive their risk of developing esophageal adenocarcinoma as low

BACKGROUND

The risk of developing esophageal adenocarcinoma (EAC) for patients with Barrett's esophagus (BE) is approximately 0.5% per year.

OBJECTIVE

To investigate how patients with BE estimate and perceive their risk of developing EAC.

DESIGN

Questionnaire study.

SETTING

Patients with BE who were undergoing surveillance endoscopy based on histologic and flow cytometric results.

PATIENTS

A total of 192 patients with BE were included.

MAIN OUTCOME MEASUREMENTS

Individual patients were asked to estimate the numerical risk to develop EAC for patients with BE in general and for themselves. How patients perceived their own risk was measured on a scale from "very small" to "very large."

RESULTS

At least 1 question was filled out by 169 patients (88% response). Sixty percent of respondents underestimated the numerical risk for patients with BE, in general, to develop EAC, while even more patients (69%) underestimated their own risk. Most respondents perceived their own risk as very small or small (63%).

LIMITATIONS

Risk estimations may depend on the response scale used.

CONCLUSIONS

Most patients with BE underestimated the numerical risk and perceived their risk of developing EAC as (very) low. Despite a low perceived risk, all patients in this group adhered to endoscopic surveillance.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Endoscopic treatment of Barrett's oesophagus

Barrett's oesophagus develops as a consequence of severe gastro-oesophageal reflux. The importance of Barrett's oesophagus lies in the small risk of developing high-grade dysplasia and subsequent adenocarcinoma. Because of poor treatment results in patients with advanced adenocarcinoma, surveillance of patients with Barrett's oesophagus for the development of dysplasia, although not uncontroversial, is widely practised in the gastroenterological community. The aim of surveillance is to detect adenocarcinoma in an early stadium where surgical cure is possible. In recent years several endoscopic treatments for both high-grade dysplasia and intramucosal adenocarcinoma have been developed. In this review some basic aspects of Barrett's oesophagus are discussed together with endoscopic treatments such as endoscopic mucosal resection, local thermal treatments and photodynamic therapy. Although surgical resection is probably the treatment of choice in fit patients, local endoscopic treatments should be considered in patients with high-grade dysplasia or intramucosal carcinoma who are unfit or unwilling to have surgery.

MUC4 is increased in high grade intraepithelial neoplasia in Barrett's oesophagus and is associated with a proapoptotic Bax to Bcl-2 ratio

BACKGROUND

Patients with Barrett's oesophagus (BO) are at risk of oesophageal adenocarcinoma. Because the pattern of mucosal mucins changes during neoplastic progression, it may serve as a marker of intraepithelial neoplasia.

AIMS

To determine the expression pattern of mucins in neoplastic BO epithelium (high grade dysplasia) and correlate it with the expression of apoptosis markers Bax and Bcl-2.

METHODS

Thirty seven patients with BO were studied: 16 without intraepithelial neoplasia, six with high grade intraepithelial neoplasia (HGN), and 15 with infiltrating adenocarcinoma. Biopsies were obtained from squamous epithelium, Barrett's epithelium, and (when present) foci of suspected HGN or adenocarcinoma. MUC1-4, MUC5AC, MUC5B, MUC6, Bax, and Bcl-2 mRNA were determined by semiquantitative RT-PCR. MUC2, MUC5AC, and MUC6 protein was determined by immunoblotting.

RESULTS

Mucin expression varied between neoplastic progression stages in BO. Mucin mRNA levels were low in squamous epithelium, except for MUC4, and were at least four times higher in BO and HGN (p<0.001), but less so in adenocarcinoma. MUC4 expression was significantly lower in BO than in normal squamous epithelium, whereas in HGN and adenocarcinoma, levels were significantly higher than in BO (p = 0.037). The Bax:Bcl-2 ratio was increased in HGN compared with BO (p = 0.04). MUC2, MUC5AC, and MUC6 protein values correlated with mRNA data.

CONCLUSIONS

Mucin expression varies during the development of oesophageal adenocarcinoma in BO. MUC4 could serve as a tumour marker in this process. In contrast to animal studies, upregulation of MUC4 in HGN is associated with increased apoptosis, suggesting that MUC4 plays a minor role in apoptosis regulation in BO.

Barrett's oesophagus: new diagnostic and therapeutic techniques

BACKGROUND

Barrett's oesophagus is associated with an increased risk of developing adenocarcinoma. Cancer development is preceded by dysplastic changes. Yet, detection of these microscopic changes has remained beyond the reach of routine endoscopy. Endoscopic screening in Barrett's therefore relies mainly on extensive random biopsy sampling.

METHODS

Update on new endoscopic diagnostics techniques for Barrett's oesophagus.

RESULTS

Application of new optical techniques has the potential to enhance our ability to detect dysplasia during endoscopic procedures and take targeted biopsies. Spectral information can be obtained either by point measurements using an optical fibre ('spectral biopsy') or by imaging a broad tissue field. Light-induced fluorescence techniques are based on the observation that tissue when excited by light of shorter wavelength will emit fluorescent light of a longer wavelength. This concept can be used to image tissue in vivo, based on minimal biochemical and structural changes of the (sub)mucosa. Elastic scattering spectroscopy is a spectral biopsy technique that can be exploited even to detect low-grade dysplasia, based on structural information of the mucosa, in which the size and crowding of nuclei in the epithelial layer play a key role. Optical coherence tomography uses reflection of light at optically scattering structures for cross-sectional tissue imaging. Compared to B-scan ultrasonography, optical coherence tomography offers a much higher resolution (10-20 micron), without the need for tissue contact or acoustic coupling. These spectral techniques, although still in their infancy, have already shown the ability to detect early cancer, high-grade dysplasia and in some cases even low-grade dysplasia with a promising degree of sensitivity. As the instruments and the techniques will be further refined, they are likely to become an important part of endoscopic screening. Advances in endoscopic treatment techniques make early malignancies, for which surgical resection is the only accepted therapy, amenable for minimally invasive endoscopic treatment. Endoscopic mucosal resection is a minimally invasive endoscopic technique that can be used in patients with circumscribed mucosal carcinomas. The technique is also useful as a diagnostic procedure by obtaining a full-thickness mucosal specimen for histologic examination. Photodynamic therapy using the prodrug 5-aminolevulinic acid is an ablative therapy that destroys the oesophageal mucosa, leaving the deeper layers of the oesophageal wall intact. Cell damage is achieved by the action of light on the photosensitizing agent protoporphyrin IX in the mucosa, with skin photosensitivity of less than 48 h. Such mucosal ablation, however, can also be accomplished with more common thermal techniques like argon plasma coagulation. In all these ablative procedures, squamous regeneration is obtained by rigorous antacid therapy. In selected patients, these endoscopic ablation methods, although still experimental, might already offer an alternative to oesophagectomy. The need for further improvement, in conjunction with the lack of long-term follow-up data, however, limits the use of these techniques to expert centres.

CONCLUSION

New endoscopic techniques are likely to change the diagnostic and therapeutic procedures for Barrett's oesophagus in the near future.