Prognostic Significance of HLA Class I Expressing in Gastric Carcinoma Defined by Monoclonal Anti-Pan HLA Class I Antibody, EMR8-5

Abstract

Downregulation or loss of HLA class I molecules has been demonstrated in human cancers. The aim of this study was to assess the clinical significance of HLA class I expression in gastric cancer. Gastric cancer tissues from 189 patients were examined for expression of HLA class I heavy chain antigens by immunohistochemical staining with EMR8-5. The expression level of HLA class I of tumor cells is categorized by combining an estimate the percentage of immunoreactive cell with an estimate of the staining intensity. The relationship between HLA class I expression and clinicopathologic parameters, patient survival, and tumor recurrence were analyzed. HLA class I was downregulated in 85 (45.0%) of the gastric carcinomas. Staining revealed 104 (55.0%) tumors with strongly positive expression of HLA class I antigens, 76 (40.2%) tumors with weakly positive expression, and 9 (4.8%) tumors with negative expression. The expression of HLA class I antigen did not correlate with any other clinicopathologic parameters. Moreover, HLA class I expression was neither a risk factor for tumor recurrence nor survival. The downregulation of HLA class I expression is not associated with patient prognosis.