Background: Combined androgen blockade (cab) is a promising treatment modality for prostate cancer (pca). In the present meta-analysis, we compared the efficacy and safety of first-line cab using an antiandrogen (aa) with castration monotherapy in patients with advanced pca.
Methods: PubMed, embase, Cochrane, and Google Scholar were searched for randomized controlled trials (rcts) published through 12 December 2016. Hazard ratios (hrs) with 95% confidence intervals (cis) were determined for primary outcomes: overall survival (os) and progression-free survival (pfs). Subgroup analyses were performed for Western compared with Eastern patients and use of a nonsteroidal aa (nsaa) compared with a steroidal aa (saa).
Results: Compared with castration monotherapy, cab using an aa was associated with significantly improved os (n = 14; hr: 0.90; 95% ci: 0.84 to 0.97; p = 0.003) and pfs (n = 13; hr: 0.89; 95% ci: 0.80 to 1.00; p = 0.04). No significant difference in os (p = 0.71) and pfs (p = 0.49) was observed between the Western and Eastern patients. Compared with castration monotherapy, cab using a nsaa was associated with significantly improved os (hr: 0.88; 95% ci: 0.82 to 0.95; p = 0.0009) and pfs (hr: 0.85; 95% ci: 0.73 to 0.98; p = 0.007)-a result that was not achieved with cab using a saa. The safety profiles of cab and monotherapy were similar in terms of adverse events, including hot flushes, impotence, and grade 3 or 4 events, with the exception of risk of diarrhea and liver dysfunction or elevation in liver enzymes, which were statistically greater with cab using an aa.
Conclusions: Compared with castration monotherapy, first-line cab therapy with an aa, especially a nsaa, resulted in significantly improved os and pfs, and had an acceptable safety profile in patients with advanced pca.
Keywords: Prostate cancer, advanced; androgen blockade, combined; antiandrogens; castration monotherapy; overall survival; progression-free survival; safety.