Significance of serum soluble Fas ligand in patients with bladder carcinoma

BACKGROUND, The interaction of Fas and Fas ligand (FasL) plays an important role in cytotoxic T-lymphocyte-mediated and natural killer cell-mediated a poptosis against tumor cells. Circulating soluble FasL (sFasL) has been sug gested to provide protection from Fas-mediated apoptosis. The current study examined this possi bility in patients with bladder carcinoma. METHODS. The levels of sFasL in the serum of 163 patients with bladder carc inoma were determined using an enzyme-linked immunoadsorbent assay. Antiaut ologous tumor cytotoxic activity was assessed by the 12-hour chromium isoto pe (Cr-51) release assay. RESULTS, The mean serum level of sFasL in patients with bladder carcinoma w as 2.5-fold higher than that in healthy donors. The level of serum sFasL in patients with muscle-invasive bladder carcinoma was 2.5-fold higher than t hat in patients with superficial bladder carcinoma. In addition, serum sFas L levels in patients with T1 and Tis bladder carcinoma was 2-fold and 2.7-f old higher, respectively, than levels in patients with Ta bladder carcinoma . The serum level of patients with sFasL in Grade 3 bladder carcinoma were 2.4-fold and 1.7-fold higher than that in patients with Grade 1 and Grade 2 bladder carcinoma, respectively. Patients with Ta bladder carcinoma with a low level of serum sFasL (less than the median value) had a longer postope rative tumor-free interval than patients with a high sFasL level (greater t han the median value) in the 5-year follow-up. There was an apparent invers e correlation between the level of serum sFasL and antiautologous tumor cyt otoxic activity. CONCLUSIONS, The results of the current study demonstrated that the level o f serum sFasL is correlated with both disease progression and increase in t he tumor grade, and that an elevated serum sFasL level predicted early recu rrence in patients with Ta bladder carcinoma. These findings suggest that e levated serum sFasL levels might be associated with a greater risk of disea se progression and recurrence in patients with bladder carcinoma. (C) 2001 American Cancer Society.