Rising prostate-specific antigen values during neoadjuvant androgen deprivation therapy: The importance of monitoring.

Abstract

To assess the impact of a rising prostate-specific antigen (PSA) level in patients receiving neoadjuvant androgen deprivation therapy (N-ADT) before external beam radiotherapy for prostate cancer. From prospectively collected data, we identified 182 patients who received between 3 and 12 months of N-ADT before definitive external beam radiotherapy and who had at least three PSA readings during the neoadjuvant period. One hundred fifty patients had PSA values that continued to fall (Non-Rise group), but 32 had a PSA value that started to rise (Rise group). The two groups were compared by Mann-Whitney U and Pearson chi-square tests. Kaplan-Meier and log-rank analyses were performed for time to treatment failure, cause-specific survival (CSS), and overall survival (OS). The median follow-up was 62.5 months for the Non-Rise group and 53 months for the Rise group. Patients who sustained a PSA rise during the N-ADT period had a shorter time to PSA relapse (p = 0.013), poorer CSS (p = 0.027), and poorer OS (p = 0.03). Multivariate analysis confirms the significance of a PSA rise during the N-ADT period for CSS (p = 0.035) and OS (p = 0.038). A subset of patients treated with N-ADT develop a rising PSA profile that likely represents early androgen resistance. They have significantly worse outcome.