Cancer and soluble FAS.

A test system developed by the authors was used to measure serum concentrations of soluble Fas in patients with malignant and benign tumors of different location and morphology. Relationships between soluble Fas levels and the main clinical and morphological characteristics of cancer were evaluated. It is proven that the concentrations and incidence of detection of soluble Fas in the sera of patients with tumors are significantly higher than in normal subjects. No appreciable differences in the concentrations of soluble Fas were detected in malignant and benign tumors of the mammary gland, bones, ovaries, and adrenals. In thyroid cancer, soluble Fas levels were higher than in benign and hyperplastic processes in this organ. High level of soluble Fas is associated with late stages of the disease (ovarian cancer, cancer of the corpus uteri, adrenocortical and colorectal cancer) and with poor differentiation of the tumor (ovarian cancer and cancer of the corpus uteri), with local metastases (colorectal and adrenocortical cancer), and with tumor invasion into the myometrial tissue, intestinal wall, and adjacent tissues (cancer of the corpus uteri and colorectal cancer). A significantly high level of soluble Fas was detected in colorectal and adrenocortical cancer in the presence of at least 2 local metastases. Soluble Fas levels depended on tumor histogenesis in malignant and benign ovarian tumors. High concentration of soluble Fas was detected in large tumors in patients with ovarian cancer, cancer of the corpus uteri, colorectal cancer, thyroid cancer and adenoma, and in adrenocortical cancer. Initially high levels of soluble Fas are characteristic of patients whose tumors are little sensitive to nonadjuvant radiotherapy. The overall 5-year survival of patients with low levels of soluble Fas is better in osteosarcoma, cancer of the corpus uteri, ovarian and adrenocortical cancer.