Prostate cells usually require testosterone and other androgens to survive

Split people in two groups of Casodex resistant treatment men (double -blind cross-over study) 

50% get Casodex 50 mg ( BICALUTAMIDE 50 MG ) 1 tablet daily + 1 placebo tablet 
Casodex is an anti testosterone agent. 

50% get Casodex 50 mg 1 tablet daily + 1 Tamoxifen 20 mg tablet 
Tamoxifen is an estrogen receptor inhibitor 

Compare the results of tumor growth over 1 year's time then reverse the groups without the physician or the patient knowing if they are receiving tamoxifen or the placebo tamxoifen then compare tumor growth results again.