Active surveillance in low-risk patients with prostate cancer: preliminary analysis of predictive factors associating with deferred treatment.

16047 Background: Active surveillance (AS) protocols aim to detect patients (pts) with indolent disease, whom a radical therapy could be spared to. We report preliminary analysis of factors potentially correlating with the possibility of deferring treatment (DFT).,Since 2005 AS has been proposed to low-risk pts as an alternative to active treatment(s). Entry criteria: informed consent, initial PSA (iPSA) ≤10 ng/ml, clinical stage ≤T2a (1992 TNM), Gleason Pattern Score ≤3+3 (no GP ≥ 4), positive biopsy cores ≤20%, max core length containing cancer ≤ 50%. Follow-up (fu) is scheduled as follows: PSA and DRE every 3 mos, TRUS every 6 mos, re-biopsy every yr for the 1 2 yrs and every 2 yrs afterwards. Pts drop out the study due to PSA doubling time (DT) ≤ 2 yrs, total PSA > 10 ng/ml, disease upgrading and/or upsizing at re-biopsy, pt's choice. The individual predicted PSA evolution over time is calculated using the Klotz formulae (J Urol 2006).,Between 03/2005 and 12/2007, SA was proposed to 192 pts and was accepted by 80 pts (fu: 1-39 mos, median 12 mos). 20/80 pts dropped out the study after 5- 24 mos: 2 pts due to PSADT, 2 to PSA > 10 ng/ml, 6 to upgrading and 8 pts due to disease upsizing; 2 pts entered a watchful waiting program due to worsening of their performance status. 18/20 pts underwent DFT: 10 pts chose EBRT, 2 BRT and 6 radical prostatectomy. To date, no unfavorable outcome has been observed. PSA velocity, iPSA and age did not significantly associate with DFT, while PSADT < 3 yrs showed a trend towards significance (p=0.07) when compared with PSADT ≥3 yrs or negative (DFT in 35.7% vs 21% of pts, respectively). When considering PSA evolution over time using the Klotz formulae, 7/38 pts were classified as at high risk (HR) of progression, 19/38 were at low risk and 12/38 pts were at intermediate risk. 6/7 pts at HR of progression dropped out form SA protocol.,AS was accepted by half of eligible pts. Due to the still limited number of pts, we did not detect any significant correlation between DFT and iPSA, PSADT, age or PSA velocity. The use of Klotz formulae seems to be a promising tool to identify pts at HR for disease progression. The study is partly supported by Fondazione Italo Monzino, Milan, Italy No significant financial relationships to disclose.