Down-regulation of HLA class I antigen is an independent prognostic factor for clear cell renal cell carcinoma

Purpose: We determined the prognostic impact of human leukocyte antigen class I on the survival of patients with clear cell renal cell carcinoma. Materials and Methods: Immunohistochemical staining for HLA class I was performed on specimens from 45 patients with clear cell renal cell carcinoma. We performed univariate and multivariate analyses of various factors affecting cause specific survival including HLA class I, Fuhrman grade, TNM stage and tumor size. Furthermore, we compared the survival of patients with HLA class I positive renal cell carcinoma to that of those with down-regulated HLA class I using the Kaplan-Meier method and log rank test. Results: HLA class I was immunohistochemically down-regulated in 17 (37.8%) clear cell renal cell carcinomas. The down-regulation had no correlation with other clinicopathological parameters such as tumor size, perirenal fat invasion, tumor thrombus, TNM stage or nuclear grade. Univariate and multivariate analyses revealed that HLA class I expression, tumor grade and TNM stage were significant factors influencing the disease specific survival of patients with renal cell carcinoma. Patients with HLA class I positive renal cell carcinoma had longer recurrence-free survival than those with down-regulated expression at 5-year followup (95.5% and 61.1%, respectively). Conclusions: Our data demonstrate that down-regulation of HLA class I on tumor cells is an independent prognostic factor for clear cell renal cell carcinoma. This finding suggests that HLA class I restricted cytotoxic T lymphocytes have an important role in the suppression of renal cell carcinoma.