p16, cyclin D1, Ki-67, and AMACR as markers for dysplasia in Barrett esophagus

Barrett esophagus (BE) (BE) is in 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, it 18)7 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 cytoplasillic 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 DI expression was present in almost all cases. bill high expression ( > 50% cells positive) was displayed mostly in HGD and AdenoCa (46.7% and 42.1%, respectively). Ki-67 index increased with the severity of dysplasia and labeling extended from the lower third of the Crypts 10 file 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 bind extent ol'A'NIACR staining also increased with the severity of dysplasia. Aberrant 1) 16 and high-cyclin DI 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.