Soluble Fas (sFas) and soluble Fas ligand (sFas-L) balance in laryngeal carcinoma before and after surgical treatment

Background and Objectives: Fas and its specific ligand (Fas-L), both of which are involved in apoptosis, exist in membrane-bound and soluble forms. The soluble forms (sFas and sFas-L) have been observed in various tumours, but their clinical significance has not yet been clarified. The aim of this study was to assess serum sFas and sFas-L levels in patients with laryngeal squamous cell carcinoma (LSCC) and their possible correlations with surgical treatment. Methods: Serum sFas and sFas-L levels were determined by ELISA in samples taken from 26 LSCC patients on the day before surgery (T0), and 2 weeks (T1) and 6 months after surgery (T2), and in samples taken from 35 healthy volunteers. Results: The mean serum sFas levels in the 35 healthy volunteers and the 26 LSCC patients at T0 were respectively 5941 ± 411 pg/ml and 6290 ± 652 pg/ml (P = 0.63), and the mean serum sFas-L levels were 0.1 ± 0.05 ng/ml and 2.95 ± 0.8 ng/ml (P < 0.0001). After surgery, there was a statistically significant decrease in sFas at both T1 (P < 0.05) and T2 (P < 0.01), and in sFas-L at T2 (P < 0.01). Conclusions: The decrease in sFas and sFas-L levels after surgery suggest that they may be produced by or closely linked to tumour cells. Larger prospective clinical studies of patients with LSCC will be needed to establish the clinical significance of sFas and sFas-L, as reported for other neoplasms.