SERUM INTERLEUKIN-6 IN RELATION TO ACUTE-PHASE REACTANTS AND SURVIVALIN PATIENTS WITH RENAL-CELL CARCINOMA

Patients with malignancies often present with signs of inflammatory re actions such as elevated erythrocyte sedimentation rate (ESR) and C-re active protein (CRP). Since interleukin-6 (IL-6) is a possible regulat or of these reactions and has been proposed as a predictor of prognosi s, the aim of the study was to analyse its clinical significance in pa tients with renal cell carcinoma. Serum samples were collected from 19 6 patients before any treatment. IL-6 was analysed by an enzyme-linked immunoassay and compared with tumour grade, stage, acute-phase reacta nts and survival. Patients with renal cell carcinoma had significantly higher IL-6 levels (mean 28.1 +/- 63.4 ng/l; median 8.3 ng/l) compare d with controls (mean 1.7 +/- 2.6 ng/l; median 0.5 ng/l; P < 0.001). S erum IL-6 levels in patients with distant metastases were significantl y higher than for patients with tumours confined to the kidney (P = 0. 02). This difference was more pronounced when serum IL-6 levels in pat ients with poorly differentiated tumours were compared with well-diffe rentiated tumours (P < 0.001). A significant correlation between the a cute-phase reactants CRP, ESR and IL-6 levels was found. Survival time was significantly shorter (P = 0.001) for patients with IL-6 levels a bove the median serum level compared with patients with lower levels. Similar significant prognostic results were obtained in the group of p atients with metastatic disease, but not in group of patients with sta ge I-III. Serum levels of IL-6 correlated to tumour stage, grade and a cute-phase reactants. Increased levels were related to the presence of metastases and adverse survival. Serum IL-6 proved univariate prognos tic information but this prognostic significance was lost using a mult ivariate analysis. (C) 1997 Elsevier Science Ltd.