Metastatic Castration-Resistant Prostate Cancer: Two Case Reports of Dramatic Response with Abiraterone Acetate in Patients Heavily Pretreated with Chemotherapy
In April 2004, a 58-year-old male presented with a PSA of 17.9 ng/ml, T3 and Gleason 7 (3 + 4) prostate adenocarcinoma. He underwent pelvic lymph node ablation, showing an invasion of the right ilio-obturatory nodes. A bone scan as well as a thoraco-abdominal CT were normal. The patient was treated with prostatic (70 G) and pelvic (50 G) radiation therapy, followed by gosereline acetate (10.8 mg every 3 months for 6 months). His post-treatment PSA nadir was 1 ng/ml in July 2004.\nIn October 2007, progression occurred with an increase in PSA, CT showing enlarged lumbo-aortic nodes as well as lumbar bone metastases. The patient began ADT with gosereline acetate (10.8 mg every 3 months) and bicalutamide 50 mg/day from June 2007 to December 2007, followed by spine radiation therapy. In January 2008, as PSA progressed, docetaxel (75 mg/m2 every 3 weeks with prednisone 10 mg daily/6 cycles) was started. A partial response was obtained, and ADT was resumed after chemotherapy. In January 2009, while PS was 1, a new progression occurred with bone pain, radiographic progression (bone, liver, hydronephrosis) as well as PSA increase. A mitroxantrone/prednisone treatment was proposed (10 mg/m2, 3 cycles), but treatment was poorly tolerated and the disease continued to progress.\nFrom 2009 through 2011, the patient received a total of 5 separate regimens for his progressing metastatic disease: zoledronic acid, stilboestrol, oral vinorelbine (80 mg weekly, 6 cycles), docetaxel (60 mg/m2, 3 cycles), and carboplatin/VP16 (3 cycles: carboplatin AUC 4 and VP16 100 mg/m2 for C1, carboplatin AUC 4 and VP16 80 mg/m2 for C2 and carboplatin AUC 3.75 and VP16 75 mg/m2 for C3). However, the disease progressed and PS deteriorated to 3.\nIn March 2011, a named-patient treatment with abiraterone was started at a dose of 1,000 mg/day together with prednisone 10 mg/day. Before abiraterone, PSA was 504 ng/ml and PS was 3; main metastatic lesions were located in the bones, lumbo-aortic nodes, liver, urinary tract (hydronephrosis) and lungs. Moreover, the patient had ascite and lower limb edema.\nQuickly after abiraterone initiation, the patient had a sharp clinical improvement (PS 1). Biological response (PSA decrease at 281 ng/ml) was obtained after 1 month of treatment. No side effects were attributed to abiraterone treatment. After 3 months of treatment, radiological partial response was achieved (fig. ) and PSA was 54 ng/ml with PS 1.\nIn August 2011, PS deteriorated, lower limb edema increased, and the patient died.