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


METHODS
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).


RESULTS
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).


CONCLUSIONS
A subset of patients treated with N-ADT develop a rising PSA profile that likely represents early androgen resistance. They have significantly worse outcome.
Niblock
Paddy
P
Radiation Therapy Program, Vancouver Center, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
Pickles
Tom
T
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000401:mortality / Q000532:radiotherapy; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D017211:Treatment Failure
D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen