Circulating soluble Fas ligand in patients with gastric carcinoma.

BACKGROUND: The Fas/Fas ligand (FasL) system is involved in cancer cell death induced by the immune system. Most of the tumors may escape the host immune attack by imitating themselves as immune-privileged sites by overexpressing FasL. FasL is synthesized as a membrane-bound protein that can be cleaved to the soluble isoform (sFasL). The objectives of this work were to determine whether the serum concentrations of sFasL in patients with gastric carcinoma were correlated with clinicopathologic features and survival rates.
METHODS: The authors examined the circulating sFasL concentration in 43 healthy people and 166 primary gastric carcinoma patients at the time of diagnosis by enzyme linked immunoadsorbent assay. The results were categorized by 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 carcinoma in a manner reflective of the disease stages such as the depth of tumor invasion, lymph node metastasis, and distant metastasis. The authors determined the cutoff value (0.08 ng/mL) as a 90th percentile of healthy controls. The survival analysis demonstrated that patients with high sFasL levels had a worse prognosis than those with low levels (P < 0.001). Multivariable analysis confirmed that the sFasL concentration was an independent prognostic 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. Copyright 2000 American Cancer Society.