[A case of advanced prostate fibrosarcoma that reacted well to chemotherapy]

Prostate fibrosarcoma is an extremely rare tumor for which complete excision has been the mainstay of treatment. Although chemotherapy has been attempted in cases with positive surgical margins and/or advanced stage disease, the effectiveness of this therapy has not been established. Herein, we report a case of advanced prostate fibrosarcoma that reacted well to chemotherapy. A 40-year-old man was referred for treatment of a large prostatic tumor with multiple lung, liver, and bone metastases. Needle biopsy of the prostate revealed that the tumor was a high-grade undifferentiated sarcoma. Chemotherapy with doxorubicin and ifosfamide was administered. After five courses of chemotherapy, the primary prostate tumor decreased markedly, and the lung and liver metastases almost disappeared. Radical cystoprostatectomy and ileal conduit formation were performed. Pathological diagnosis was fibrosarcoma. Another three courses of doxorubicin and ifosfamide therapy were performed, and doxorubicin was replaced by etoposide because the maximum dose of doxorubicin was reached. However, the effectiveness of the second-line therapy was poor, and the tumor progressed again. The patient died of lung metastasis 15 months later.