Investigation of the prognostic significance of c-kit and c-erb-b2 expression in osteosarcoma, ewing sarcoma, and rhabdomyosarcoma and comparison with clinical parameters

Objective: In the present study, the prognostic and treatment-guiding roles of the c-erb-B2 oncoprotein and tyrosine kinase receptor c-kit in osteosarcoma (OS), Ewing sarcoma (ES), and rhabdomyosarcoma (RMS) were evaluated. Materials and methods: With 25 cases from each group, c-kit and c-erb-B2 expression were investigated immunohistochemically in a total of 75 cases. Results: Staining for c-kit was found to be positive in 15 (60%) of the RMS, 11 of the OS (44%), and 11 of the ES cases (44%). C-erbB-2 staining was positive in 7 RMS cases (8%) and negative in all cases of OS and ES.The SISH method was applied to six c-erb-B2 positive RMS cases, and amplification of the HER2 gene (encoding c-erb-B2) was detected in one case. It was determined that c-kit expression in OS was significantly associated with survival (p<0.05) and could be considered as a poor prognostic parameter. In contrast,c-kit expression had no prognostic significance in ES and RMS. In the RMS group, there was no relationship between c-erb-B2 positivity and prognosis. Conclusion: It was concluded that c-kit expression can be used as a poor prognostic parameter for OS and therapy targeting c-kit may be an alternative treatment option.