In metastatic prostate cancer the main systemic treatment is androgen suppression (AS), either by surgical castration (orchiectomy) or by long-term use of a luteinizing-hormone-releasing-hormone agonist. The low plasma concentrations of androgens that remain, which are chiefly of adrenal origin, could be further reduced by addition of long-term treatment with nonsteroidal antiandrogen such as nilutamide, flutamide, or cyproterone acetate. Such combination of AS with an antiandrogen is referred to as total androgen blockade (TAB). There have been many randomized trials comparing TAB with AS alone but, on average, they involved only a few hundred patients each. In this meta-analysis, the researchers reviewed the mortality and morbidity findings from all the available trials of TAB versus AS in advanced prostate cancer.
A total of 20 trials of 6320 patients that included a randomization of immediate nonsteroidal antiandrogens with castration (TAB) versus castration alone (AS) for metastatic prostate cancer were included.
In metastatic prostate cancer, addition of a nonsteroidal antiandrogen to castration only improved the 5-year survival by about 5%. Although this overview brought together all available randomized evidence on survival, it did not assess other medical outcomes, quality of life, or treatment costs. Longer follow-up is needed to draw any definitive conclusions.