Expression of proto-oncogene c-kit in high risk prostate cancer

Aims We determined whether c-kit proto-oncogene is expressed in prostate cancer and whether its expression is related with biochemical relapse in high risk localized prostate cancer patients. Methods c-Kit expression was evaluated by immuno-histochemistry in 94 prostate cancer samples from patients treated by radical prostatectomy followed by adjuvant hormonal therapy because all patients had a pT3a stage (initially cT2 stage). All patients presented a >7 Gleason score and a >10 pre-operative PSA value. We evaluated association between c-kit positive staining and disease free survival. Results In 26 of 94 prostate cancer, we found an epithelial positive c-kit expression. The epithelial expression was found in the peripheral zone of prostate tissue. 13/94 relapsed and, although not statistically significant (p 0.055), a trend to a higher risk of relapse among the c-kit positive samples was observed in our series of prostate cancer patients. Conclusions Our study is only an initial experience and it is necessary to consider a higher number of patients to clarify whether c-kit is really an independent predictor for disease recurrence. Further study in this area will help to understand whether anti c-kit drugs could become an effective complement to the armamentarium of prostate cancer therapies.