The type of patients who would benefit from anti-androgen withdrawal therapy: could it be performed safely for aggressive prostate cancer?

This study was designed to detect the factors that were significantly associated with the results of anti-androgen withdrawal (AAWD) therapy, and to examine whether patients with aggressive prostate cancer demonstrating a short prostate-specific antigen (PSA)-doubling time (DT) could benefit from it without even greater exacerbation of the disease. We conducted a retrospective chart review study of 121 patients who received AAWD therapy due to failed combined androgen blockade (CAB) therapy. A reduction in the serum PSA level after AAWD was observed in 35 patients (28.9 %), and a greater than 50 % decrease from the baseline serum PSA level was observed in 16 patients (13.2 %). Shortening of PSA-DT after AAWD was observed in 48 patients (39.7 %). Univariate and multivariate analyses demonstrated that only a long duration of prior anti-androgen treatment was selected as a significant predictor for a good response to AAWD therapy. With respect to exacerbation after AAWD, we found that patients with a short baseline PSA-DT conversely had a low risk of subsequent shortening of PSA-DT. Using these two factors, we could stratify the patients into four groups, and patients with prior duration of anti-androgen >18 months and PSA-DT ≤3 months demonstrated the best results with a good response rate (67.9 %) and a low risk for a worsening of the disease (14.3 %). We conclude that AAWD would be effective especially for patients whose cancer progressed rapidly (short PSA-DT) after a long stable period under CAB and should be recommended before embarking on the next therapeutic maneuver.