Fas/FasL in neuroblastoma O

Background: Recent evidences indicated that tumor cells could induce apoptosis of T cells by combining Fas on active T cells ' surface with self-expressed FasL to escape immune surveillance. This study was undertaken to detect the expression of the Fas/FasL system in neuroblastoma (NB) tissues and its clinical significance in clinical practice. Methods: Immunohistochemical staining was performed to detect the expression of Fas and FasL in 40 cases of NB. The relations among Fas and FasL expression, clinical stages, pathological types, and postoperative survival time of patients were analyzed. Results: The positive expression rates of Fas in I-II, III-IV and IV-S stages were 64.3%, 22.2 % and 50.0% respectively (P<0.05). The positive expression rate of FasL in III-IV stage was 33.3%, which was significantly higher than that in I-II (21.4%) and IV-S stages (12.5%). FasL expression rates in patients with NB (28.1%) and unfavorable histology (UFH) (33.3%) were higher than those of patients with ganglioneuroblastoma (GNB) (12.5%) and favorable histology (FH) (15.8%). However, Fas expression rates in patients with GNB (50%) and FH (63.2%) were higher than those of patients with NB (40.6%) and UFH (23.8%). A positive correlation was observed between Fas expression and postoperative survival time (n=25, r=0.354), but no obvious correlation between FasL expression and postoperative survival time