BACKGROUND. The meta-analysis of maximal androgen blockade (MAB) concluded that there is no survival advantage of MAB over castration alone. However, the results from the largest trials yield conflicting results. METHODS. The design and results of three trials were examined. RESULTS. Most studies were planned to detect an over-optimistic difference in survival and immature data were published. The survival curves show that statistical assumptions are not fulfilled. Excluding from the meta-analysis all trials where a negative impact of disease flare on survival could not be excluded resulted in no difference in survival between MAB and castration. CONCLUSIONS. Trials of MAB should be planned to detect differences of no more than 5-10% in median survival. The analyses should only be carried out on mature data and should take into account the possibility of a negative impact on survival due to disease flare if no anti-androgen has been given initially with an LH-RH agonist.

Maximal androgen blockade, Metastatic prostate cancer, Statistical design,
The Prostate
Department of Urology

Collette, L.A.J, Studer, U.E, Schröder, F.H, Denis, L.J, & Sylvester, R. (2001). Why phase III trials of maximal androgen blockade versus castration in M1 prostate cancer rarely show statistically significant differences. The Prostate, 48(1), 29–39. doi:10.1002/pros.1078