EUS and EMR/ESD: Is EUS in patients with Barrett’s esophagus with high-grade dysplasia or intramucosal adenocarcinoma necessary prior to endoscopic mucosal resection?

Abstract

The management of patients with HGD in BE remains controversial, largely because the natural history of this condition is so poorly defined. For example, Reid et al. reported a 59 % 5-yr cumulative cancer incidence among 76 patients with HGD in BE [1],whereas Schnell et al. found that only 12 (16 %) of their 75 patients with HGD developed adenocarcinoma during a mean follow-up period of 7.3 yr [2]. Four management options have been proposed for patients with HGD in BE: (1) esophagectomy, (2) endoscopic ablative therapies, (3) EMR, and (4) intensive endoscopic surveillance, in which invasive therapy is withheld until biopsy specimens show evidence of invasion [3]. Clearly, there are risks associated with all of these approaches, and all would benefit from accurate staging of the neoplasia. Estimation of the depth of tumor penetrationThe less than perfect reliability of endoscopic staging with the adjunct of chromo endoscopy and magnification endoscopy for the estimation of cancer depth before EMR can be improved by the use of endoscopic ultrasonography (EUS), in particular highfrequency US probe sonography (HFUPS). HFUPS may distinguish nine layers within the wall of GI organs in contrast to a five-layered structure seen with conventional EUS, thus providing better images that are useful in the evaluation of transmural penetration and in differentiating cancers limited to the mucosa from those with submucosal penetration. The main limitation of HFUPS is its tendency to overstage early lesions. The diagnostic accuracy of HFUPS in assessing depth of tumor invasion in the esophagus, stomach and colon ranges from 67 % to 94 % among the published studies [4 ± 9]. This high variability in HFUPS accuracy may reflect the use of probes with different penetration (15MHz versus 20MHz) and differences in the patient populations studied. Accuracy of HFUPS, in fact, is significantly better for elevated type lesions than for depressed ones [7].When different techniques are used in combination to select lesions suitable for EMR, the overall accuracy is high [10]. Because of the limitations of these staging techniques, however, it has been suggested that when a lesion meets the generally accepted criteria of size, and appearance is encountered, EMR can be performed without prior HFUPS, as long as the lesion can safely be removed in its entirety [11 ± 12]. Submucosal injection used to facilitate EMR can also help to decide whether or not to continue with the procedure [13]. The observation of a bleb formation with elevation of the overlying mucosa indicates the absence of deep submucosal involvement and the feasibility of EMR [30] On the other hand, the dense fibrosis associated with deep submucosal invasion prevents fluid infiltration through the submucosal connective tissue, decreasing bleb formation and elevation of the lesion [14]. This so-called ªnon-lifting sign has been found to have 100 % sensitivity, 99 % specificity, and 83 % positive predictive value for invasive carcinoma in patients with early cancer of the colon [15...

Diagnostic performance of EUS in predicting advanced cancer among patients with Barrett’s esophagus and high-grade dysplasia/early adenocarcinoma: systematic review and meta-analysis

“…14,15 However, its role among patients with BE with HGD or biopsyproven early adenocarcinoma (EAC) is not well established. 16 If patients are shown to have advanced disease (tumor invading the submucosa or beyond or lymph node involvement) on EUS, endoscopic therapy may not be warranted. However, some authors have questioned the need for EUS in this patient group.…”

Endoscopic Therapy of Esophageal Premalignancy and Early Malignancy

“…However, recent work reporting immunohistochemical studies specific for lymphatic endothelium suggests that the lamina propria in the normal esophagus in fact has an extensive network of lymphatic vessels, 18 and the increasing risk of metastases in T1b lesions cannot be entirely explained based on lymphatic density. 22 Although EUS is appropriate in staging early adenocarcinoma to rule out lymph node metastasis, accurate assessment of depth of invasion is difficult. 23 The overall accuracy of EUS for T staging ranges from 72% to 76%.…”

The international emergence of endoscopic submucosal dissection for early gastric cancer

“…16 In the absence of further data and ensuing guidelines, it seems reasonable to adopt a practice pattern for ESD in the management of EGC analogous to that being used for dysplastic Barrett's esophagus. 17 In this model, a detailed high-definition endoscopic assessment (in conjunction with biopsies guided by enhanced optical imaging modalities, such as narrow-band imaging or chromoendoscopy) would be the first step. For highly dysplastic lesions, consideration may be given to performing EUS for T staging and evaluation for LN metastasis, but if high-quality EUS imaging is not obtainable, T staging by CE should be sufficient.…”