Safety and efficacy of abiraterone acetate in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: an Italian multicenter "real life" study

Background: To evaluate the safety and efficacy of abiraterone acetate (AA) in the "real life" clinical practice for men with chemotherapy-naive metastatic castration-resistant prostate. Methods: A consecutive series of patients with mCRPC in 9 Italian tertiary centres treated with AA was collected. Demographics, clinical parameters, treatment outcomes and toxicity were recorded. The Brief Pain Inventory scale Q3 was tracked and patient treatment satisfaction was evaluated. Survival curves were estimated by the method of Kaplan-Meier and Cox regression and compared by the log-rank test statistic. Results: We included 145 patients (mean age 76.5y). All patients were on androgen deprivation therapy. Patients had prior radiotherapy, radical prostatectomy, both treatments or exclusive androgen deprivation therapy in 17%, 33%, 9% and 40%, respectively. 57% of the patients had a Gleason score higher more than 7 at diagnosis. 62% were asymptomatic patients. The median serum total PSA at AA start was 17 ng/mL (range 0,4-2100). The median exposure to AA was 10 months (range 1-35). The proportion of patients achieving a PSA decline >= 50% at 12 weeks was 49%. Distribution of patient satisfaction was 32% "greatly improved", 38% "improved", 24% "not changed", 5.5% "worsened". Grade 3 and 4 toxicity was recorded in 17/145 patients 11.7% (70% cardiovascular events, 30% critical elevation of AST/ALT levels). At the last follow-up, median progression free and overall survival were 17 and 26. 5 months, respectively. Both outcomes significantly correlated with the presence of pain, patient satisfaction, PSA baseline and PSA decline. Conclusions: The AA is effective and well tolerated in asymptomatic or slightly symptomatic mCRPC in a "real life" setting. The survival outcomes are influenced by the presence of pain, patient satisfaction, baseline PSA and PSA decline.