Androgen Deprivation Therapy for Node-Positive Prostate Cancer: Adjuvant Does Not Mean Salvage

Abstract

TO THE EDITOR: I read with interest the study by Wong et al on the role of androgen deprivation therapy (ADT) in patients who had metastatic regional lymph nodes after radical prostatectomy. As mentioned by the authors, the results of the randomized trial by Messing et al showing a significant advantage in progression-free survival and overall survival in patients who received immediate (rather than delayed at time of metastasis) ADT have led to the standard use of adjuvant ADT for node-positive patients. However, this study was conducted before the prostate-specific antigen (PSA) era and the contemporary practice of surveillance policy with salvage ADT at biochemical recurrence. Therefore, the benefit of adjuvant ADT is not clear, and additional investigations are required. Unfortunately, the methodology used by Wong et al does not allow any useful conclusion to be drawn. Indeed, the major limitation is the absence of data regarding PSA values at onset of ADT. Was ADT administered as an adjuvant treatment in patients who achieved undetectable PSA after surgery or as salvage treatment in patients with biochemical recurrence? For an adjuvant therapy, the choice of 120 days is obviously not optimal. In general oncology, adjuvant treatment is required as soon as possible after local therapy. In prostate cancer, ADT is supposed to be initiated within 8 weeks after surgery (ie, after reaching PSA value 0.1 ng/mL). Therefore, it is highly suspected that patients who received ADT within 120 days of prostatectomy had undetectable (adjuvant ADT) or detectable (salvage ADT) PSA. In my opinion, 150 days or more after prostatectomy, the whole population of patients would have had detectable PSA. Consequently, the reported data do not provide any convincing information regarding the role of adjuvant ADT. The only conclusion can be that in the PSA era, the overall and cancer-specific survivals at 10 years for patients treated with adjuvant ADT or salvage ADT do not seem different from those observed in patients not treated with ADT after prostatectomy.