CYTOKINE LEVELS IN CYSTIC RENAL MASSES ASSOCIATED WITH RENAL-CELL CARCINOMA

Purpose: We compared cytokine levels in fluid from renal cysts with an d without renal cell carcinoma. Materials and Methods: Fluid was aspir ated from 18 renal cysts without (benign) and 21 with renal cell carci noma (malignant). Serum from patients with renal cell carcinoma and he althy controls was collected and cytokines were measured by enzyme-lin ked immunosorbent assay. Results: Interleukin-6 (IL-6) and basic fibro blast growth factor concentrations were higher in malignant than benig n cysts or serum (p < 0.006). Epidermal growth factor levels were sign ificantly higher in malignant cysts and serum than in benign cysts (p < 0.01). IL-6 levels in malignant cysts positively correlated with the erythrocyte sedimentation rate (R = 0.80) and C-reactive protein (R = 0.86), and they were higher in grade 3 than in grade 2 tumors. Basic fibroblast growth factor levels were significantly higher in malignant cysts associated with hypervascular than hypovascular tumors (p = 0.0 29). Conclusions: Cytokine levels in aspirated fluid may help to ident ify malignant renal cysts and indicate the characteristics of coexisti ng tumors.