Markers suggest reduced malignant potential of subsquamous intestinal metaplasia compared with Barrett's esophagus

Post-ablation buried neoplasia in Barrett's esophagus

Endoscopic eradication therapy (EET) with maximal acid suppression is the cornerstone for the management of patients with Barrett's esophagus (BE) associated dysplasia. The occurrence of buried dysplastic glands after re-epithelialization of a neo-squamous epithelium is of concern for endoscopists. Here, we present a patient with BE and high-grade dysplasia successfully treated by EET who developed buried dysplastic BE during surveillance. A review of literature on buried dysplasia after successful endoscopic therapy of BE is also discussed.

Allaying uncertainty in diagnosing buried Barrett's esophagus

Subsquamous intestinal metaplasia (SSIM) in the setting of Barrett's esophagus (BE) is a technically challenging diagnosis. While the risk for progression of BE involving the surface mucosa is well documented, the potential risk for development of advanced neoplasia associated with SSIM has been controversial. This study aimed to determine the effects of specimen adequacy, presence of dysplasia, and interobserver agreement for SSIM interpretation. Adult patients (n = 28) who underwent endoscopic therapy for BE with high-grade dysplasia or intramucosal carcinoma (HGD/IMC) between October 2005 and June 2013 were included. Initial evaluation (n = 140 slides) by an experienced gastrointestinal pathologist was followed by an interobserver study by 8 pathologists. Forty-seven (34%) slides had insufficient subsquamous tissue to assess for SSIM. SSIM was found in 19% of all slides and 29% of slides with sufficient subsquamous tissue. At least one slide had SSIM in 54% to 64% of patients. Subsquamous low grade dysplasia (LGD) was found in 4 (15%) slides with SSIM and subsquamous HGD/IMC was found in 5 (19%) slides with SSIM. At the patient level, 8 (53%) had no dysplasia, 4 (27%) had LGD and 3 (20%) had HGD/IMC. Overall agreement for SSIM by slide was 92% to 94% (κ = 0.73 to κ = 0.82, moderate to strong agreement), and by patient was 82% to 94% (κ = 0.65 to κ = 0.87, moderate to strong agreement). This study confirms the need for assessing specimen adequacy and assessing the prevalence of SSIM and is the first to assess interobserver agreement for SSIM and dysplasia within SSIM.

Advanced endoscopic imaging for detecting and guiding therapy of early neoplasias of the esophagus

Esophageal cancers, largely adenocarcinoma in Western countries and squamous cell cancer in Asia, present a significant burden of disease and remain one of the most lethal of cancers. Key to improving survival is the development and adoption of new imaging modalities to identify early neoplastic lesions, which may be small, multifocal, subsurface, and difficult to detect by standard endoscopy. Such advanced imaging is particularly relevant with the emergence of ablative techniques that often require multiple endoscopic sessions and may be complicated by bleeding, pain, strictures, and recurrences. Assessing the specific location, depth of involvement, and features correlated with neoplastic progression or incomplete treatment may optimize treatments. While not comprehensive of all endoscopic imaging modalities, we review here some of the recent advances in endoscopic luminal imaging, particularly with surface contrast enhancement using virtual chromoendoscopy, highly magnified subsurface imaging with confocal endomicroscopy, optical coherence tomography, elastic scattering spectroscopy, angle-resolved low-coherence interferometry, and light scattering spectroscopy. While there is no single ideal imaging modality, various multimodal instruments are also being investigated. The future of combining computer-aided assessments, molecular markers, and improved imaging technologies to help localize and ablate early neoplastic lesions shed hope for improved disease outcome.

Indications, contraindications and limitations of endoscopic therapy for Barrett's esophagus and early esophageal adenocarcinoma

Endoscopic eradication therapy (EET) has revolutionized management of Barrett's esophagus (BE)-associated neoplasia, traditionally treated by esophagectomy, which carries very high mortality and morbidity. EET, usually performed in the outpatient setting, has a safe risk profile. It is indicated in patients with BE with high-grade dysplasia and intramucosal cancer, confirmed, and persistent low-grade dysplasia, and in highly selected cases of non-dysplastic BE and submucosal cancers. Multiple EET modalities are available and can be categorized into two groups: ablation therapies and resection techniques with resection techniques usually reserved for nodular/raised lesions or lesions with suspected neoplasia. Patients usually require multiple ablation sessions with a goal of achieving complete eradication of metaplasia. Despite very good results, EET has its limitations and is not 100% effective: it targets a small subset of patients along the spectrum of BE and esophageal adenocarcinoma, as most patients with esophageal adenocarcinoma remain asymptomatic until the disease has progressed to advanced stages. Post-ablation surveillance is mandatory, as recurrences are common. An area of concern is buried metaplasia reported to occur following ablation therapy and thought to be from de novo growth of metaplastic tissue underneath the neosquamous epithelium, following ablation. The focus of this review article is to present the indications, contraindications and limitations of EET.

Advanced Imaging for Barrett's Esophagus and Early Neoplasia: Surface and Subsurface Imaging for Diagnosis and Management

PURPOSE OF REVIEW

Esophageal adenocarcinoma bears one of the fastest rising incidence of any cancers and generally arises in the setting of gastroesophageal reflux and Barrett's esophagus. However, early detection of neoplasia can be challenging since most patients are asymptomatic until they progress to more advanced and less curable stages, and early dysplastic lesions can be small, multifocal, and difficult to detect. Clearly, new imaging tools are needed in light of sampling error associated with random biopsies, the current standard of practice.

RECENT FINDINGS

Advances in endoscopic imaging including virtual chromoendoscopy, confocal laser endomicroscopy, and subsurface imaging with optical coherence tomography have ushered in a new era for detecting subtle neoplastic lesions. Moreover, in light of esophagus-sparing treatments for neoplastic lesions, such tools are likely to guide ablation and follow-up management. While there is no ideal single imaging modality to facilitate improved detection, staging, ablation, and follow-up of patients with dysplastic Barrett's esophagus, new advances in available technology, the potential for multimodal imaging, and the use of computer-aided diagnosis and biomarkers all hold great promise for improving detection and treatment.

Recent advances in Barrett's esophagus

Barrett's esophagus (BE) is the only known precursor of esophageal adenocarcinoma, one of the few cancers with increasing incidence in developed countries. The pathogenesis of BE is unclear with regard to either the cellular origin of this metaplastic epithelium or the manner in which malignant transformation occurs, although recent data indicate a possible junctional origin of stem cells for BE. Treatment of BE may be achieved using endoscopic eradication therapy; however, there is a lack of discriminatory tools to identify individuals at sufficient risk for cancer development in whom intervention is warranted. Reduction in gastroesophageal reflux of gastric contents including acid is mandatory to achieve remission from BE after endoscopic ablation, and can be achieved using medical or nonmedical interventions. Research topics of greatest interest include the mechanism of BE development and transformation to cancer, risk stratification methods to identify individuals who may benefit from ablation of BE, optimization of eradication therapy, and surveillance methods to ensure that remission is maintained after eradication is achieved.

Depth-resolved imaging of colon tumor using optical coherence tomography and fluorescence laminar optical tomography

Early detection of neoplastic changes remains a critical challenge in clinical cancer diagnosis and treatment. Many cancers arise from epithelial layers such as those of the gastrointestinal (GI) tract. Current standard endoscopic technology is difficult to detect the subsurface lesions. In this research, we investigated the feasibility of a novel multi-modal optical imaging approach including high-resolution optical coherence tomography (OCT) and high-sensitivity fluorescence laminar optical tomography (FLOT) for structural and molecular imaging. The C57BL/6J-Apc^Min/J mice were imaged using OCT and FLOT, and the correlated histopathological diagnosis was obtained. Quantitative structural (scattering coefficient) and molecular (relative enzyme activity) parameters were obtained from OCT and FLOT images for multi-parametric analysis. This multi-modal imaging method has demonstrated the feasibility for more accurate diagnosis with 88.23% (82.35%) for sensitivity (specificity) compared to either modality alone. This study suggested that combining OCT and FLOT is promising for subsurface cancer detection, diagnosis, and characterization.

Barrett's Esophagus: A Comprehensive and Contemporary Review for Pathologists

This review provides a summary of our current understanding of, and the controversies surrounding, the diagnosis, pathogenesis, histopathology, and molecular biology of Barrett's esophagus (BE) and associated neoplasia. BE is defined as columnar metaplasia of the esophagus. There is worldwide controversy regarding the diagnostic criteria of BE, mainly with regard to the requirement to histologically identify goblet cells in biopsies. Patients with BE are at increased risk for adenocarcinoma, which develops in a metaplasia-dysplasia-carcinoma sequence. Surveillance of patients with BE relies heavily on the presence and grade of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating dysplasia, particularly with regard to the more recently recognized unconventional variants. Identification of non-morphology-based biomarkers may help risk stratification of BE patients, and this is a subject of ongoing research. Because of recent achievements in endoscopic therapy, there has been a major shift in the treatment of BE patients with dysplasia or intramucosal cancer away from esophagectomy and toward endoscopic mucosal resection and ablation. The pathologic issues related to treatment and its complications are also discussed in this review article.

Endoscopy for diagnosis and treatment in esophageal cancers: high-technology assessment

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the endoscopic tools to recognize squamous cell dysplasia; confocal laser endomicroscopy for Barrett's esophagus; confocal microscopy in the cancer patient; optical coherence tomography in the assessment of subsquamous Barrett's metaplasia; endoscopic mucosal resection for high-grade dysplasia in Barrett's esophagus; HALO in the treatment of squamous dysplasia; and the use of fluorescence in situ hybridization to detect dysplasia and adenocarcinoma in patients with Barrett's esophagus.