The timing of androgen ablation therapy and/or chemotherapy in the treatment of prostatic cancer.

The effect of varying the timing of androgen ablation alone and in combination with chemotherapy on tumor growth rate and host survival has been studied using the serially transplantable Dunning R-3327 H rat prostatic adenocarcinoma as a model. These studies have demonstrated three basic points: 1) When either androgen ablation or Cytoxan chemotherapy are given as a single agent treatment, they are both most effective when given as early as possible; 2) when androgen ablation is combined with Cytoxan chemotherapy, it is most effective when both therapies are begun simultaneously and as early as possible; and 3) when androgen ablation and Cytoxan treatment are begun simultaneously and early, it is possible to increase survival above that found for either treatment when given optimally as single modalities (ie, such simultaneous early treatment enhances the individual therapeutic effectiveness of both treatments).