Utility of ancillary studies in the diagnosis and risk assessment of Barrett's esophagus and dysplasia

The Aberrant Expression of Biomarkers and Risk Prediction for Neoplastic Changes in Barrett's Esophagus-Dysplasia

Background: Barrett's esophagus (BE) is a pre-neoplastic condition associated with an increased risk of esophageal adenocarcinoma (EAC). The accurate diagnosis of BE and grading of dysplasia can help to optimize the management of patients with BE. However, BE may be missed and the accurate grading of dysplasia based on a routine histology has a considerable intra- and interobserver variability. Thus, well-defined biomarker testing remains indispensable. The aim of our study was to identify routinely applicable and relatively specific biomarkers for an accurate diagnosis of BE, as well as determining biomarkers to predict the risk of progression in BE-dysplasia. Methods: Retrospectively, we performed immunohistochemistry to test mucin 2(MUC2), trefoil factor 3 (TFF3), p53, p16, cyclin D1, Ki-67, beta-catenin, and minichromosome maintenance (MCM2) in biopsies. Prospectively, to identify chromosomal alterations, we conducted fluorescent in situ hybridization testing on fresh brush samples collected at the time of endoscopy surveillance. Results: We discovered that MUC2 and TFF3 are specific markers for the diagnosis of BE. Aberrant expression, including the loss and strong overexpression of p53, Ki-67, p16, beta-catenin, cyclin D1, and MCM2, was significantly associated with low-grade dysplasia (LGD), high-grade dysplasia (HGD), and EAC histology, with a relatively high risk of neoplastic changes. Furthermore, the aberrant expressions of p53 and p16 in BE-indefinite dysplasia (IND) progressor cohorts predicted the risk of progression. Conclusions: Assessing the biomarkers would be a suitable adjunct to accurate BE histology diagnoses and improve the accuracy of BE-dysplasia grading, thus reducing interobserver variability, particularly of LGD and risk prediction.

Gastro-Esophageal Junction Precancerosis: Histological Diagnostic Approach and Pathogenetic Insights

Barrett's esophagus (BE) was initially defined in the 1950s as the visualization of gastric-like mucosa in the esophagus. Over time, the definition has evolved to include the identification of goblet cells, which confirm the presence of intestinal metaplasia within the esophagus. Chronic gastro-esophageal reflux disease (GERD) is a significant risk factor for adenocarcinoma of the esophagus, as intestinal metaplasia can develop due to GERD. The development of adenocarcinomas related to BE progresses in sequence from inflammation to metaplasia, dysplasia, and ultimately carcinoma. In the presence of GERD, the squamous epithelium changes to columnar epithelium, which initially lacks goblet cells, but later develops goblet cell metaplasia and eventually dysplasia. The accumulation of multiple genetic and epigenetic alterations leads to the development and progression of dysplasia. The diagnosis of BE requires the identification of intestinal metaplasia on histologic examination, which has thus become an essential tool both in the diagnosis and in the assessment of dysplasia's presence and degree. The histologic diagnosis of BE dysplasia can be challenging due to sampling error, pathologists' experience, interobserver variation, and difficulty in histologic interpretation: all these problems complicate patient management. The development and progression of Barrett's esophagus (BE) depend on various molecular events that involve changes in cell-cycle regulatory genes, apoptosis, cell signaling, and adhesion pathways. In advanced stages, there are widespread genomic abnormalities with losses and gains in chromosome function, and DNA instability. This review aims to provide an updated and comprehensible diagnostic approach to BE based on the most recent guidelines available in the literature, and an overview of the pathogenetic and molecular mechanisms of its development.

Aberrant p53 Expression in Gastric Biopsies and Resection Specimens Following Neoadjuvant Chemoradiation: A Diagnostic Pitfall

Gastric mucosal biopsies and resections from patients treated with neoadjuvant radiation and/or chemotherapy are frequently encountered. These samples may show histologic features related to therapy including inflammation, ulceration, and epithelial atypia. In some cases, epithelial atypia may be marked, prompting the use of adjunct p53 immunohistochemistry. We examined p53 expression by immunohistochemistry in gastric mucosa following therapy.

We evaluated the histology and p53 immunohistochemical expression in gastric mucosa from 57 resections and 3 mucosal biopsies, from 60 patients treated with radiation and/or chemotherapy for gastroesophageal carcinoma (n  =  33) or pancreatic carcinoma (n  =  27).

We identified histomorphologic features of therapy-related epithelial changes in 50 of 60 cases (83%). Abnormal p53 expression was present at least focally in nearly half the cases (27 of 60 cases; 45%), all of which showed morphologic evidence of therapy-related epithelial changes. Neuroendocrine cell micronests were present in 37 of 60 cases (62%). Next-generation sequencing (NGS) of foci with therapy-related epithelial changes showing abnormal p53 expression and carcinoma from the same patient was attempted and yielded results in 1 patient. Interestingly, differing TP53 alterations in the patient's adenocarcinoma and in a histologically benign esophageal submucosal gland with therapy-related epithelial changes and abnormal p53 expression were identified.

Our results demonstrate that abnormal p53 expression is relatively common in gastric mucosal samples following radiation and/or chemotherapy and suggest that p53 expression should be avoided when distinguishing therapy-related changes from dysplasia or carcinoma. Furthermore, our NGS results raise interesting biological questions, which may warrant further investigation.

[Barrett's esophagus: histochemical difference between goblet cells and blue cells]

Background

Barrett's esophagus (BE) is the replacement of the usual esophageal mucosa by a simple columnar epithelium with the presence of goblet cells (GC) of intestinal type. It has been related to different risk factors such as gastroesophageal reflux disease (GERD), inappropriate consumption of irritating foods, smoking and overweight. There are CC mimic cells, known as blue cells (BC), which make the diagnosis of BE difficult, due to the lack of a precise definition of the nature and location of the gastroesophageal junction and the microscopic variations in this area.

Objective

To identify morphologically and with histochemical techniques Alcian blue (AA) and periodic acid-Schiff (PAS) between GC and BC.

Material and methods

Retrolective cross-sectional analytical study where 45 samples of patients diagnosed with BE were included.

Results

The morphological characteristics are similar in both cell varieties. PAS staining was 100%, unlike AA staining, with only 16 cases with staining, corresponding to 35.55%.

Conclusions

PAS staining has a high sensitivity and specificity for the identification of GC, this being a fundamental pillar for the correct diagnosis of BE. The presence of BC detected by AA does not exclude the diagnosis of BE, since both cell types can coexist.

RISK OF PRENEOPLASTIC LESIONS IN MUCOSAL PROJECTIONS OF DIFFERENT SIZES OF THE COLUMNAR EPITHELIUM IN THE LOWER ESOPHAGUS

BACKGROUND

Barrett's esophagus is an acquired condition that predisposes to the development of esophageal adenocarcinoma.

AIMS

The aim of this study was to establish an association between the endoscopic and the histopathological findings regarding differently sized endoscopic columnar epithelial mucosa projections in the low esophagus, under 3.0 cm in the longitudinal extent.

METHODS

This is a prospective study, including 1262 patients who were submitted to upper gastrointestinal endoscopy in the period from July 2015 to June 2017. The suspicious projections were measured and subdivided into three groups according to the sizes encountered (Group I: <0.99 cm; Group II: 1.0-1.99 cm; and Group III: 2.0-2.99 cm), and biopsies were then performed.

RESULTS

There was a general prevalence of suspicious lesions of 6.42% and of confirmed Barrett's lesions of 1.17%, without a general significant statistical difference among groups. However, from Groups I and II to Group III, the differences were significant, showing that the greater the lesion, the higher the probability of Barrett's esophagus diagnosis. The absolute number of Barrett's lesions was 7, 9, and 6 for Groups I, II, and III, respectively.

CONCLUSIONS

The findings led to the conclusion that even projections under 3.0 cm present a similar possibility of evolution to Barrett's esophagus. If, on the one hand, short segments are more prevalent, on the other hand, the long segments have the higher probability of Barrett's esophagus diagnosis, which is why biopsies are required in all suspicious segments.