Purpose: Clear cell renal cell carcinoma (ccRCC) is an immunogenic tumor that can progress in the presence of an intact host immune system. We previously reported that survivin and B7-H1 are independently associated with disease progression and death when expressed by ccRCC tumors. Herein, we examine the clinical effect of ccRCC combined expression of both survivin and B7-H1.
Experimental design: Specimens from 298 patients who underwent nephrectomy for ccRCC between 1990 and 1994 were immunohistochemically stained for survivin and B7-H1. Cancer-specific survival was estimated using the Kaplan-Meier method. Associations of both markers with ccRCC death were assessed using Cox proportional hazards regression models.
Results: At last follow-up, 94 patients died from ccRCC. Among the living patients, the median follow-up was 11.2 years (range, 0-15 years). There were 177 (59.4%) survivin(Low)/B7-H1(-), 51 (17.1%) survivin(Hi)/B7-H1(-), 29 (9.7%) survivin(Low)/B7-H1(+), and 41 (13.8%) survivin(Hi)/B7-H1(+) tumors. The 5-year cancer-specific survival rates for patients within each group were 89.3%, 59.7%, 70.0%, and 16.2%, respectively. Combined survivin(Hi)/B7-H1(+) expression was associated with ccRCC death univariately (risk ratio, 12.82; 95% confidence interval, 7.50-21.92; P < 0.001) and in multivariate analysis (risk ratio, 2.81; 95% confidence interval, 1.56-5.04; P < 0.001). Survivin(Hi)/B7-H1(+) tumors exhibited increased levels of infiltrating mononuclear cells and survivin-specific T cells compared with survivin(Low)/B7-H1(-) tumors.
Conclusion: Patients with survivin(Hi)/B7-H1(+) ccRCC tumors are at increased risk of ccRCC death. Survivin(Hi)/B7-H1(+) tumors also harbor increased amounts of infiltrating mononuclear cells and survivin-specific T cells relative to survivin(Low)/B7-H1(-) tumors. Taken together, dual expression of survivin and B7-H1 can be used to predict ccRCC tumor aggressiveness.