Research Articlesp16, Cyclin D1, Ki-67, and AMACR as Markers for Dysplasia in Barrett EsophagusShi, Xue Ying MD, PhD* †; Bhagwandeen, Brahm MD, FRCPA, FRCPath*; Leong, Anthony S-Y. MD, FRCPA, FRCPath, FCAP, FASCP, FHKAM (Pathol), Hon FHKCPath, Hon FRCPT* †Author Information *Division of Anatomical Pathology, Hunter Area of Pathology Service, Newcastle, Australia †Department of Pathology, School of Basic Medical Sciences, Peking University, Beijing, China Dr Shi was supported by a HAPS Research Fellowship. Disclosure/Conflict of Interest: No conflict of interest to declare. Reprints: Anthony S-Y. Leong, MD, FRCPA, FRCPath, FCAP, FASCP, FHKAM (Pathol), Hon FHKCPath, Hon FRCPT, Hunter Area Pathology Service, Locked Bag 1, Hunter Regional Mail Centre, NSW 2310, Australia (e-mail: [email protected]). Received for publication November 19, 2007; accepted January 11, 2008 Applied Immunohistochemistry & Molecular Morphology: October 2008 - Volume 16 - Issue 5 - p 447-452 doi: 10.1097/PAI.0b013e318168598b Buy Metrics 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 α-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. © 2008 Lippincott Williams & Wilkins, Inc.