Prevalent low-grade dysplasia: the strongest predictor of malignant progression in Barrett's columnar-lined oesophagus

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.

Low-grade dysplasia in Barrett's esophagus: A problematic diagnosis

Although low-grade dysplasia (LGD) in Barrett's esophagus (BE) is a histopathological diagnosis based on different histological abnormalities, it is still problematic for different reasons. Patients without confirmed diagnosis of LGD undergo unnecessary and intensified follow-up where the risk of progression is low in the majority of cases. In contrast, the presence of confirmed LGD indicates a high risk of progression. In this article we try to address these reasons focusing on re-confirmation of LGD diagnosis, interobserver agreement, and persistent confirmed LGD. The progression risk of LGD to high-grade dysplasia and esophageal adenocarcinoma will also be reviewed.

Barrett's esophagus: The pathomorphological and molecular genetic keystones of neoplastic progression

Barrett's esophagus is a widespread chronically progressing disease of heterogeneous nature. A life threatening complication of this condition is neoplastic transformation, which is often overlooked due to lack of standardized approaches in diagnosis, preventative measures and treatment. In this essay, we aim to stratify existing data to show specific associations between neoplastic transformation and the underlying processes which predate cancerous transition. We discuss pathomorphological, genetic, epigenetic, molecular and immunohistochemical methods related to neoplasia detection on the basis of Barrett's esophagus. Our review sheds light on pathways of such neoplastic progression in the distal esophagus, providing valuable insight into progression assessment, preventative targets and treatment modalities. Our results suggest that molecular, genetic and epigenetic alterations in the esophagus arise earlier than cancerous transformation, meaning the discussed targets can help form preventative strategies in at-risk patient groups.

Improved Progression Prediction in Barrett's Esophagus With Low-grade Dysplasia Using Specific Histologic Criteria

Risk stratification of patients with Barrett's esophagus (BE) is based on diagnosis of low-grade dysplasia (LGD). LGD has a poor interobserver agreement and a limited value for prediction of progression to high-grade dysplasia or esophageal adenocarcinoma. Specific reproducible histologic criteria may improve the predictive value of LGD. Four gastrointestinal pathologists examined 12 histologic criteria associated with LGD in 84 BE patients with LGD (15 progressors and 69 nonprogressors). The criteria with at least a moderate (kappa, 0.4 to 0.6) interobserver agreement were validated in an independent cohort of 98 BE patients with LGD (30 progressors and 68 nonprogressors). Hazard ratios (HR) were calculated by Cox proportional hazard regression analysis using time-dependent covariates correcting for multiple endoscopies during follow-up. Agreement was moderate or good for 4 criteria, that is, loss of maturation, mucin depletion, nuclear enlargement, and increase of mitosis. Combination of the criteria differentiated high-risk and low-risk group amongst patients with LGD diagnosis (P<0.001). When ≥2 criteria were present, a significantly higher progression rate to high-grade dysplasia or esophageal adenocarcinoma was observed (discovery set: HR, 5.47; 95% confidence interval [CI], 1.81-17; P=0.002; validation set: HR, 3.52; 95% CI, 1.56-7.97; P=0.003). Implementation of p53 immunohistochemistry and histologic criteria optimized the prediction of progression (area under the curve, 0.768; 95% CI, 0.656-0.881). We identified and validated a clinically applicable panel of 4 histologic criteria, segregating BE patients with LGD diagnosis into defined prognostic groups. This histologic panel can be used to improve clinical decision making, although additional studies are warranted.