Circulating soluble Fas ligand in patients with gastric carcinoma

BACKGROUND. The Fas/Fas ligand (FasL) system is involved in cancer cell dea th induced by the immune system. Most of the tumors may escape the host imm une attack by imitating themselves as immune-privileged sites by overexpres sing FasL. FasL is synthesized as a membrane-bound protein that can be clea ved to the soluble isoform (sFasL). The objectives of this work were to det ermine whether the serum concentrations of sFasL in patients with gastric c arcinoma were correlated with clinicopathologic features and survival rates . METHODS. The authors examined the circulating sFasL concentration in 43 hea lthy people and 166 primary gastric carcinoma patients at the time of diagn osis by enzyme linked immunoadsorbent assay. The results were categorized b y clinical and histopathologic variables. RESULTS. The serum sFasL levels of healthy subjects were all. less than 0.1 ng/mL. Among the 166 gastric carcinoma patients, the median concentration of sFasL was 0.04 ng/mL. There were no significant differences between the healthy controls and the gastric carcinoma patients group (P = 0.738). The sFasL levels were significantly increased in patients with gastric carcinom a in a manner reflective of the disease stages such as the depth of tumor i nvasion, lymph node metastasis, and distant metastasis. The authors determi ned the cutoff value (0.08 ng/mL) as a 90th percentile of healthy controls. The survival analysis demonstrated that patients with high sFasL levels ha d a worse prognosis than those with low levels (P < 0.001). Multivariable a nalysis confirmed that the sFasL concentration was an independent prognosti c indicator of overall survival (P = 0.041). CONCLUSIONS, Our results indicated that sFasL concentrations could not be a new marker for early detection of gastric carcinoma but a prognostic tumor marker for the assessment of the progression of advanced gastric carcinoma . Cancer 2000;89: 2560-4. (C) 2000 American Cancer Society.