p16, Cyclin D1, Ki-67, and AMACR as Markers for Dysplasia in Barrett Esophagus

Abstract

Barrett esophagus (BE) is an established precursor of esophageal adenocarcinoma (AdenoCa). One hundred and one cases of BE diagnosed by esophageal biopsy and resections were examined morphologically for dysplasia. These were categorized as BE without dysplasia (n=25), indefinite for dysplasia (IND, n=17), low-grade dysplasia (LGD, n=18), high-grade dysplasia (HGD, n=15), and AdenoCa (n=26). Immunostaining for p16 (INK4A/CDKN2A), Cyclin D1 (CCND1), Ki-67, and alpha-methylacyl-CoA racemase (AMACR) was employed to assess their potential as diagnostic discriminators. Abnormal p16 expression (negative, cytoplasmic, or combined cytoplasmic and nuclear staining) was present in all categories, rising from 68% in BE without dysplasia to 100% in AdenoCa, with cytoplasmic staining only showing a significant correlation with the severity of dysplasia. Cyclin D1 expression was present in almost all cases, but high expression (>50% cells positive) was displayed mostly in HGD and AdenoCa (46.7% and 42.3%, respectively). Ki-67 index increased with the severity of dysplasia and labeling extended from the lower third of the crypts to the superficial epithelium. The frequency of AMACR-positivity was 12% in BE, 47.1% in IND, 44.4% in LGD, 93.3% in HGD, and 96.2% in AdenoCa. The intensity and extent of AMACR staining also increased with the severity of dysplasia. Aberrant p16 and high-cyclin D1 expression may reflect early genetic events during the progression of Barrett-associated carcinogenesis. Cytoplasmic staining of p16 is specific. It may represent a different pathway of p16 dysfunction. The pattern and extent of Ki-67 staining and AMACR overexpression are useful additional parameters for identifying dysplasia in BE.

Anti-phosphorylated histone H3 expression in Barrett's esophagus, low-grade dysplasia, high-grade dysplasia, and adenocarcinoma

“…That study also found AMACR staining in 21% of samples that were originally diagnosed as indefinite for dysplasia. These findings were supported by the results of a study from Scheil-Bertram et al 19 However, a recent study by Shi et al 20 showed AMACR expression at the rates of 12% in Barrett's esophagus without dysplasia, 47% in indefinite for dysplasia, 44% in low-grade dysplasia, 93% in highgrade dysplasia, and 96% in adenocarcinoma, suggesting that AMACR has lower specificity for distinguishing between Barrett's esophagus with and without dysplasia. The strength of AMACR is that the test is a simple qualitative assessment of positive cells.…”

Altered expression of CD44 and DKK1 in the progression of Barrett’s esophagus to esophageal adenocarcinoma

“…Approaches chosen have included morphometry, cell adhesion molecule expression, DNA ploidy analysis, loss of heterozygosity at the chromosomal level, p53 mutations and immunohistochemical overexpression, proliferative activity (through immunohistochemical staining of the Ki-67 antigen), p16 anomalies (including promoter methylation, mutations, and loss of heterozygosity), activation of the Wnt pathway (through adenomatous polyposis coli mutations, β-catenin mutations, or one of the other players in Wnt signaling), analysis of patterns of promoter methylation, and more [10][11][12][13][14][15][16]. Although a voluminous literature exists on this subject, as yet, the only clinically used biomarker with a high predictive value is the presence of HGD [10].…”

Early Diagnostic Biomarkers for Esophageal Adenocarcinoma—The Current State of Play

“…In contrast to cyclin D1, expression of p16 protein results in cell-cycle arrest in G 1 phase as it has been shown to inhibit cyclin-dependent kinase-induced phosphorylation of retinoblastoma protein. Early genomic abnormalities during EAC development significantly affect p16 protein expression, which can be determined using immunostaining and implemented as a potential biomarker (95). Further large-scale trials are required to confirm cell-cycle abnormalities during EAC development to implement them as a biomarker.…”