Preoperative Androgen Deprivation Therapy: Artificial Lowering of Serum Prostate Specific Antigen without Downstaging the Tumor

Abstract

We studied 22 patients with clinical stage B2 (T2c) or C (T3) prostate cancer who underwent androgen deprivation therapy before radical prostatectomy as part of a downstaging protocol (group 1). The concentration of serum prostate specific antigen (PSA) was determined before and at the conclusion of androgen deprivation therapy, just before the operation. For each group 1 patient a match patient who had not received preoperative endocrine therapy (group 2) was chosen. The age of the group 2 patients was similar to that of the group 1 patients. The clinical stage of disease and pretreatment tumor grade in group 2 were identical to the stage and grade in group 1, and the serum PSA value in group 2 was similar to that of group 1 before initiation of androgen deprivation therapy. In group 1 the median serum PSA concentration was 14.8 ng./ml. (range 3.1 to 99) before endocrine therapy and 0.2 ng./ml. (range 0.1 to 3.4) after hormonal treatment. Group 2 had a median level of 13.3 ng./ml. (range 3.4 to 100). The median decrease in the serum PSA concentration for group 1 as a result of androgen deprivation therapy was 98.5%. The radical prostatectomy specimens from these 2 groups of similar patients had no difference with regard to maximal tumor dimension, pathological stage and deoxyribonucleic acid ploidy status. These findings indicate that serum PSA becomes an unreliable indicator of disease status after initiating preoperative androgen deprivation therapy and that preoperative androgen deprivation therapy has little or no benefit for decreasing the extent of tumor or pathological stage. The concept of downstaging is misleading and must be examined in a randomized clinical trial.