Anti-Phosphohistone H3 Shows Differential Expression in Barrett's Esophagus, Low-Grade Dysplasia, High-Grade Dysplasia, Adenocarcinoma Sequence
M Goodarzi, AR Rashid, DM Maru. The University of Texas MD Anderson Cancer Center, Houston
Background: High degree of interobserver variability in grading of dysplasia in Barrett's esophagus (BE) demands a biomarker which can be utilized by the practicing pathologists. Phosphorylation of histone H3 (pHH3) occurs primarily during mitosis and has shown utility as a prognostic marker in meningioma, melanocytic tumors and vulvar intraepithelial neoplasia.This study evaluated the expression of pHH3 in the metaplasia-dysplasia-carcinoma sequence in BE, and determined its utility as a supportive marker in BE and associated dysplastic lesions.
Design: The study included 102 endoscopic biopsies from 46 patients [M/F ratio: 6.6, mean age: 62] with BE and different grades of dysplasia and adenocarcinoma (ACA). In all cases, H&E sections were reviewed by two gastrointestinal pathologists in a blinded manner, and the cases were only included after consensus diagnosis. 5m sections from 28 biopsies with BE, 50 biopsies with low-grade dysplasia (LGD), 14 biopsies with high-grade dysplasia (HGD) and 10 biopsies of ACA were immunostained with anti-pHH3 antibody (rabbit polyclonal antibody , 1:400 dilution, Millipore, CA) after antigen retreival and endogenous peroxidase blocking. Anti-pHH3-labeled mitotic figures were counted in surface epithelium together with superfical and deep crypts per 10 consecutive high-power fields (using x40 HPF magnification) and the mean was calculated. Positive-staining nuclei that did not show chromatin aggregation were excluded.The mean anti-pHH3 positive cells were comapred between different lesions using student t test (SPSS, Chicago, IL). p<0.05 was considered significant.
Results: The result of immunohistochemical analysis for pHH3 is summerized in Table.
The difference in pHH3 staining between BE without dysplasia and those with LGD, HGD, or ACA was highly statistically significant (p<0.0001). The differences in pHH3 staining between LGD and HGD (p=0.0001) and between HGD and ACA (p=0.002) were statistically significant.
Conclusions: This study demonstrates that pHH3 expression is significantly increased in the neoplastic progression of BE. The immunostain for pHH3 can supplement morphologic assessment of BE and help differentiating the degree of dysplasia, particulaly in low grade dysplastic lesions.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 93, Wednesday Afternoon