Increased Soluble CD95 (sFas/CD95) Serum Level Correlates with Poor Prognosis in Melanoma Patients

Functional impairment of the Fas/CD95 receptor-ligand system is associated with the development and progression of malignancies. One possible cause might be the inhibition of the formation of a functional Fas/CD95-FasL complex by soluble Fas/CD95 molecules (sFas/CD95). In the present study we determined sFas/CD95 serum concentration in 125 melanoma patients of different clinical stages of disease compared with 30 healthy controls using an ELISA. sFas/CD95 serum level was significantly elevated ( P < 0.0005) in melanoma patients (mean ± SE = 8.60 ± 0.26 ng/ml) compared with healthy controls (mean ± SE = 6.27 ± 0.25 ng/ml). Univariate analysis revealed a correlation of sFas/CD95 serum concentration with advanced stages of disease ( P = 0.009). Only a slight increase in sFas/CD95 serum level ( P = 0.057) could be observed in regard to the tumor burden. Patients undergoing current treatment with cytostatics ( n = 18) revealed a strong increase in sFas/CD95 serum level ( P < 0.0005), whereas treatment with IFN-α alone or combined with cytostatics ( n = 19) showed no change in serum sFas/CD95 concentration. According to univariate analysis, elevated sFas/CD95 serum levels were associated with a poor overall ( P < 0.005) and a progression-free ( P < 0.0005) survival. Multivariate analysis revealed sFas/CD95 serum concentration as an independent predictive factor for progression-free ( P = 0.011), but not overall ( P = 0.078), survival. Our results show a prognostic relevance of serum sFas/CD95 in melanoma patients, indicating that the evaluation of sFas/CD95 serum level may be important for the selection of therapeutic strategies.