Clinical recurrence post-biochemical failure of prostate cancer.

Abstract

195 Background: The purpose of this study is to evaluate the role of salvage therapy (STx) after biochemical failure (bF) for prostate cancer (CaP) and to determine what factors are associated with the development of clinical recurrence (cR). Methods: From 1996-2009, 7,585 patients (pts) with CaP were treated with prostatectomy (RP), brachytherapy (PI), or external beam radiotherapy (RT). For RP patients (pts), bF was defined as a postoperative PSA >0.3 and for PI and RT pts the Phoenix definition was used. bF was documented in 927 pts. cR was defined as any image-based or pathological diagnosis of disease recurrence after bF. Cox proportional hazards regression was used to examine if the use of STx after bF, the time of bF, along with disease characteristics were associated with cR after bF. Results: The median follow-up after bF was 31months (mo; range: 0-131). Thirty percent of pts had a cR after bF, and the 5-year rate of cR free survival was 58%. STx within 1 year after bF (early) was given to 46% of pts, STx more than 1 year after bF (late) was given to 11% of pts, and 43% of pts did not receive STx. On univariate analysis, factors found to be significantly associated (p-value <0.05) with cR were a short interval between initial treatment and bF (bFTime), no use of STx, early initiation of STx, biopsy Gleason Score (bGS), clinical stage, older age at bF, the use of PI or RT, and increased frequency of PSA follow-up after bF (PSAfreq). In multivariable analysis, bFTime, no use of STx, early initiation of STx, bGS, the use of PI or RT, and PSAfreq remained significant. To better evaluate the effect the timing of initiation of STx had on the development of cR, a second analysis was preformed, limited to the 529 pts who did receive STx after bF. In multivariable analysis, early use of STx remained significant for cR (HR=2.09, 95%CI=1.24- 3.51). As a continuous variable, in a second multivariable analysis, delayed use of STx resulted in a reduced risk of developing cR (HR=0.98, 95%CI=0.96-1.00). Conclusions: This study suggests that while the use of STx after bF reduces the risk of subsequently developing cR, early use of STx after bF is not beneficial. Other factors such as the time interval between initial treatment and bF need to be evaluated when determining when to initiate STx after bF. No significant financial relationships to disclose.