Circulating soluble Fas in patients with breast cancer

It has been suggested that circulating soluble Fas (sFas) contributes to tumor progression. However, little is known about the role of sFas in breast cancer. This study was designed with the aim of elucidating the possible relation between sFas and breast cancer. A series of 57 consecutive patients with invasive breast cancer undergoing surgery were prospectively included in the study and evaluated. Venous blood samples were collected before surgery. Sera were obtained by centrifugation and stored at -70°C until assayed. The control group consisted of 12 patients with benign breast tumors (6 with fibrocystic disease, 6 with fibroadenoma). Serum concentrations of sFas were measured by the quantitative sandwich enzyme immunoassay technique. The data on primary tumor staging, age, estrogen receptor status, lymph node status, tumor grading, and TNM staging were reviewed and recorded. The mean value of circulating sFas in patients with invasive breast cancer was 794.2 ± 183.0 pg/ml and that of the control group 582.1 ± 62.8 pg/ml; the difference was significant (p < 0.001). Furthermore, there were significantly higher serum levels of sFas in the older patients (age ≥ 50) (p = 0.020) and in those with a more advanced TNM stage (p = 0.021). In the multivariate analysis, TNM stage (p = 0.005) appeared to be an independent factor for significantly higher circulating sFas in patients with invasive breast cancer. Thus circulating sFas levels may reflect the severity of invasive breast cancer. Hence the possible prognostic value of sFas for breast cancer deserves further elucidation and evaluation with long-term patient follow-up.