We studied immunophenotypic and tumor cell markers in renal cell carcinoma (RCC) to determine if there are patterns of expression which may correlate with biologic behavior and response to therapy. Fourteen RCCs from 13 patients were stained by the immunoperoxidase technique using primary antibodies to Leu 4, Leu 14, Leu 2a, Leu 3a and b, lysozyme, dendritic reticulum cell (DRC), S-100, HLA-DR, epithelial membrane antigen (EMA) and beta-2-microglobulin (B2-MG). Staining was correlated with tumor stage, nuclear grade, histologic patterns, degree of cellular infiltrate, and clinical followup. Four RCCs were stage T1, four T2, five T3, and one T4. Most tumors were clear or granular cell type, with a solid or tubular growth pattern. The number of infiltrating lymphocytes and monocytes correlated with tumor grade and stage. Tumor-infiltrating lymphocytes (TILs) were predominantly Leu 3-positive (T-helper phenotype). B-cell markers were negative. Dendritic cells were rare. HLA-DR was present on endothelial cells in 11 tumors and on tumor cells in ten. HLA-DR expression increased with tumor grade. Tumor cells expressed EMA in 12 cases; B2-MG in four cases. Two patients, stages 3 and 4, died at 2 and 6 mo.
Conclusions: (a) T-helper cells and monocytes infiltrate RCCs. Their numbers increase with tumor grade and stage. (b) HLA-DR expression by tumor cells tends to correlate with increasing stage and grade. (c) Dendritic cells are infrequent in RCCs.