The Long-term Results with Delayed-combined Androgen Blockade Therapy in Local or Locally Advanced Prostate Cancer

Abstract

To evaluate long-term clinical outcomes in cT1c-T3a prostate cancer patients following delayed-combined androgen blockade therapy. From January 2001 to December 2004, 92 cT1c-T3a prostate cancer cases were enrolled. Medical castration and anti-androgen treatment were used sequentially as delayed-combined androgen blockade therapy. Time to prostate-specific antigen biochemical failure was estimated, and risk factors for prostate-specific antigen biochemical failure were evaluated. The average patient age was 76.4 years (range, 59-91 years), the median observation period was 52.8 months (range, 26-106.6 months) and the median pre-treatment prostate-specific antigen level was 14 ng/ml (range, 3.68-492 ng/ml). The TNM classification distribution was as follows: T1c, n= 27; T2a, n = 39; T2b, n = 20; and T3a, n = 6. In the multivariate analysis, Gleason's score ≥8 (P < 0.05; hazard ratio, 3.02), prostate-specific antigen nadir >1.4 ng/ml (P = 0.001; hazard ratio, 8.76) and a half-life of the prostate-specific antigen level >1.2 months (P < 0.005; hazard ratio, 6.3) during the initial 6 months of luteinizing hormone-releasing hormone agonist monotherapy were significant independent risk factors for prostate-specific antigen biochemical failure with luteinizing hormone-releasing hormone agonist monotherapy. The high-risk group, which had at least one of these three risk factors, had a shorter time to prostate-specific antigen biochemical failure than the low-risk group, during luteinizing hormone-releasing hormone agonist monotherapy (P < 0.0001). For the total delayed-combined androgen blockade therapy observation period, the free-prostate-specific antigen biochemical failure rate was 88.3% at 5 years. Only a maintenance period following luteinizing hormone-releasing hormone agonist monotherapy (P < 0.005; hazard ratio, 16.8) was revealed to be a significant independent risk factor for prostate-specific antigen biochemical failure with total delayed-combined androgen blockade. The free-prostate-specific antigen biochemical failure rate of delayed-combined androgen blockade therapy in our study was as valuable as those in other androgen deprivation therapy of previous reports.