The Role of sFas in the Immune Escape Mechanism and Progression of Cancer Larynx

This work assess serum levels of soluble Fas form (sFas) in patients with different stages of laryngeal squamous cell carcinoma (LSCC) to investigate its prognostic significance. We correlate its levels with the morphological changes of peripheral blood cells via buffy coat examinatin. The study population included 70 patients clinically diagnosed and pathohistologically confirmed LSCC in addition to 20 healthy controls. According to TNM classification 33(47.1%) patients were in stage I (group I) and 24(34.3%) in stage II (group II) , 13(18.5%) in stage III (group III). The results revealed that the mean serum level of sFas (pg/ml) in the control group was 51.2, in group I was 66.33, in group II was 81.33 and in group III was 112.45. Statistical analysis of the mean of sFas by ELISA test in the patients’ groups in comparison to the control revealed a significant increase of both group II and III in comparison to the control group (P < 0.01) but there was no significant difference (P > 0.05) between group I in comparison to either the control or group II. There was a significant difference (P < 0.05) between group I in comparison to group III. LM examination revealed massive extent of the apoptotic cells in group III when compared to both group I and group II. EM examination of the buffy coat revealed apoptotic changes, mainly in the peripheral blood mononuclear cells (PBMNCs), represented by surface membrane ruffles and blebs with clumped nuclear chromatin and vacuolated cytoplasm. In conclusion, this study may help us to better understand one of the escape mechanisms in cancer larynx. This mechanism is represented by the significant increase in both the serum level of sFas and the morphological apoptotic changes that detected in PBMNCs. Soluble Fas may contribute to the progression of laryngeal cancer. It can be used as an attractive target for anticancer therapy and may be considered as a marker of disease progression and poor prognosis in laryngeal cancer.