Author reply

We appreciate the opportunity to respond to the letter by Rocco et al, in which they address several issues in our recently published article1 that would benefit from further clarification. At the time when this trial was conducted, options for salvage therapy of local failure after radiotherapy were very limited because salvage radical prostatectomy was considered a morbid procedure associated with a high risk of incontinence. Given a choice, patients entering our clinical trial would have avoided this procedure and even today it is not widely practiced in Canada. The question of whether some patients might have been prematurely declared as having failed therapy due to the phenomenon of prostate-specific antigen (PSA) bounce after external beam radiation is unlikely to be relevant in our study. As we reported previously,2 the mean time from irradiation to the initiation of treatment was 4.6 ± 0.3 years. Eligible patients were required to have a rising serum PSA of at least 6.0 μg/L. In fact, the mean pretreatment serum PSA level was 21.2 ± 1.6 μg/L and 83.7% of the patients had a positive biopsy at the time of registration. The mean pretreatment serum testosterone level was 13.2 ± 0.4 nmol/L and there was no suggestion of fluctuations that might have erroneously resulted in an elevation of the serum PSA. Undoubtedly, these patients had failed radiotherapy. In the overview of the randomized trials of maximum androgen blockade by the Prostate Cancer Trialists' Collaborative Group,3 the difficulty of interpreting survival relative to different forms of androgen withdrawal therapy is emphasized given the range of uncertainty, which runs from approximately 0% to approximately 5% with a margin of benefit of only 2% to 3%. However, this problem does not arise in our study,1 which focused on patients with locally advanced cancer and not metastatic disease as in the meta-analysis of randomized trials. To our knowledge, there is no evidence that cyproterone acetate in doses of 100 to 200 mg daily is detrimental in men with local disease recurrence. In addition, the data arising from our trial yield a survival rate equivalent to that observed in a similar population of healthy men (unpublished data), a finding that is consistent with the absence of major drug-related morbidity. Nicholas Bruchovsky MD, PhD, MD*, Laurence Klotz MD , Juanita Crook MD , * The Prostate Center at Vancouver General Hospital Division of Urology Department of SurgeryUniversity of British Columbia, Vancouver British Columbia, Canada, Department of Urology Sunnybrook Medical Center, Toronto Ontario, Canada, Department of Radiation Oncology Princess Margaret HospitalToronto, Ontario, Canada.

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