An ERG Gene Analysis in Two Cases with Metastatic Castration-resistant Prostate Cancer in Which Abiraterone Demonstrated Long-term Efficacy

We analyzed the ERG gene status using fluorescence in situ hybridization (FISH) in two chemotherapy-naïve cases with metastatic castration-resistant prostate cancer (mCRPC) in which abiraterone demonstrated a long-term durable complete response. FISH identified Class 1 Edel and Class 2+ Edel in case 1, and Class 1 Edel in case 2. Our experience suggests that abiraterone may be effective in cases with mCRPC and ERG gene abnormalities, particularly Class 2+ Edel or Class 1 Edel. This is the first report of two cases with mCRPC that simultaneously investigated the ERG gene status and clinical aspects, including image evaluations and pathology.