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 antiandrogen 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 PSADT. Using these two factors, we could stratify the patients into four groups, and patients with prior duration of antiandrogen > 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.