Son CH, et al. – This study was undertaken to investigate prognostic factors to select high–risk men receiving dose–escalated radiation therapy (RT) who will have favorable outcomes with short–term (ST) or no androgen deprivation therapy (ADT). The daa indicated that select men with high–risk disease treated with dose–escalated RT may not require LTADT. They found that prostate–specific antigen (PSA) nadir ≤0.2 is an independent prognostic factor correlated with freedom from distant metastases (FFDM) and cause–specific survival (CSS) in men treated with ADT. Men without GS 9 may have acceptable outcomes with STADT if PSA nadir is ≤0.2 ng/mL. Further research is needed to evaluate the role of PSA nadir in determining the optimal length of adjuvant ADT.

Methods

• Between 1988 to 2009 , researchers examined medical records of 458 men treated with definitive RT for high–risk, nonmetastatic prostate cancer at 3 academic referral centers .
• In this study, 76.4 Gy was the median dose..
• Men received no ADT (n=105), STADT (<12 mo, n=194), or long–term ADT (LTADT: ≥12 mo, n=160).
• They conducted univariate and multivariable analysis for freedom from distant metastases (FFDM) and cause–specific survival (CSS).
• For this analysis, median follow–up was 71 months.

Results

• They demonstrated that seven–year FFDM was 83% and CSS was 91%.
• In this multivariable analysis, researchers illustrated that prostate–specific antigen (PSA) nadir ≤0.2 (HR=0.36; 95% CI, 0.20–0.64) and Gleason score (GS) were associated with FFDM and CSS (all P<0.05).
• They noted that ADT duration was not correlated (P>0.05).
• Those with PSA nadir ≤0.2 ng/mL had enhanced outcomes.
• It was showed that men with GS 9 disease did poorly despite a PSA nadir ≤0.2 ng/mL and had enhanced CSS with LTADT (95% vs. 71%, P<0.05).