Background
The expressions of different markers have been immunohistochemically studied in various types of the Ewing's sarcoma family of tumors, especially for diagnostic purposes. However, little is known about their prognostic value in combination with the clinicopathological data of such patients.
Material and Method
This retrospective study investigated the immunohistochemical expressions of NSE, TdT, EMA, S-100, CK MNF116, p53, bcl-2, CD99, and CD117 on formalin-fixed paraffin-embedded material of 72 patients (age range: 2-59 years) with various types of Ewing's sarcoma family of tumors using the tissue microarray method. The immunohistochemical results were compared with clinicopathological features using survival analysis (Cox regression).
Results
CD99 expression was detected in 90%, CD117 in 75.8%, bcl-2 in 70.1%, NSE in 66.6%, p53 in 66.6%, EMA in 26%, S-100 in 25.4%, TdT in 22.1%, and CK MNF116 in 10.2% of the cases. No immunoreactivity was observed in the normal tissue around the tumors.
Conclusions
The expressions of EMA (p=0.107), NSE (p=0.126), CD99 (p=0.14), TdT (p=0.198), bcl-2 (p=0.382), p53 (p=0.54), CD117 (p=0.612), S-100 (p=0.867), and CK MNF116 (p=0.934) had no statistically significant impact on survival. Patient age at the time of diagnosis (p=0.008) and the presence of tumor necrosis (p=0.033) were the only significant prognostic factors in this study. Tumor location was an insignificant prognostic factor (p=0.38).

Keywords: Neoplasm Proteins - metabolism, Cytoplasm - pathology, Child, Preschool, Child, Adolescent, Sarcoma, Ewing - therapy, young adult