Diagnostic validity of macrophage migration inhibitory factor in serum of patients with prostate cancer: A re-evaluation

BACKGROUND. Recent studies suggest that macrophage migration inhibitory factor (MIF) in serum is of prognostic significance for Prostate cancer. The aim of this study was to re-evaluate this hypothesis. METHODS. Serum MIF levels were measured in healthy men (n = 86), untreated patients with benign prostate hyperplasia BPH; n=50), prostate cancer (PCa; n=163), and after radical prostatectomy for 3 days (n = 5). PCa patients were classified according to the TNM system and the WHO grading scale. Prostate specific antigen (PSA) and C-reactive protein (CRP) were additionally determined. RESULTS. The MIF concentrations of healthy men and BPH patients did not differ (mean +/- SD, 2.08 +/- 1.08 mug/L vs. 2.04 +/- 1.08 mug/L), whereas the mean value of MIF in PCa patients was significantly decreased (1.77 +/- 1.12 mug/L). There was no any correlation between MIF and PSA (r(s) = -0.049, P = 0.271). MIF concentrations in patients with T1 tumors were higher than in those with T2 tumors (2.29 +/- 1.26 vs. 1.67 +/- 1.11 mug/L; P = 0.044). No any effect of grading was observed. After prostatectomy, the changes of PSA and MIF were not always concordant as MIF partly increased while PSA continuously decreased. Analyses of receiver-operating curves and logistic regressions did not show that MIF alone or MIF related variables (MIF/tPSA; fPSA/(tPSA x MIF); fPSA x MIF/tPSA) could improve specificity or sensitivity to detect prostate cancer in comparison to total PSA. CONCLUSION. Serum MIF alone or MIF to PSA related variables did not seem suitable for providing additional information on PCa patients. That re-evaluated diagnostic validity of MIF was in contrast to results by another group shown previously. (C) 2004 Wiley-Liss, Inc.