[880] Predictors of Insignificant Prostate Cancer on Radical Prostatectomy (RP) Following Disease Progression during Active Surveillance (AS)

Jeong S Han, Adam D Toll, Ali Amin, Ballentine Carter, Jonathan I Epstein. The Johns Hopkins Hospital, Baltimore

Background: Since 1996, >800 men have enrolled in our AS program. Criteria for AS are: 1) biopsy (bx) with no Gleason pattern 4 or 5; 2) no core >50% involvement; 3) <3 positive cores on >12 core sampling; and 4) PSA density <0.15. Men who show worse bx findings regardless of PSA measurements on annual repeat bx are considered to have failed AS. However, some men on follow-up who fail bx criteria have “insignificant prostate cancer” on RP defined as: 1) Organ confined; 2) Dominant nodule <0.5 cm3; and 3) no Gleason pattern 4 or 5.
Design: 67 men who on annual follow-up bx failed bx criteria and subsequently underwent RP were identified. Variables evaluated included at the time of initial and failed bx: PSA, PSA density, free/total PSA, maximum % of cancer per core, extent ASAP & HGPIN, and no. of positive cores along with any interval negative biopsies.
Results: Median age at RP was 66.4 (43.4-75.0). Mean time between first bx and RP was 30.3 mos., with an average of 3 bx (2-9). Findings at RP were: non-organ confined [15 (22.4%)]; margins + [2 (3%)]; SV + [1 (1.5%)]; Gleason score 6 [30 (44.8%)]; GS 3+4=7 [(22 (32.8%)]; GS 4+3=7 [13 (19.4%)]; GS 9 [2 (3%)]. Mean and median dominant tumor nodule volume (DTV) at RP was 0.56 cc and 0.32 cc, respectively (0.01 cc-2.93 cc). 19 (28.4%) had clinically insignificant cancer at RP. DTV correlated with with PSA & maximum % cancer per core at time of failed criteria. With PSA <4 and maximum core involvement <50%, 7/8 patients (87.5%) had clinically insignificant cancer at RP vs. 5/19 (26.3%) men with PSA ≥4 ng/ml & maximum core involvement ≥50%. A subgroup analysis was done of patients (n=37) who failed AS criteria without Gleason pattern 4/5 on failed bx, as men with Gleason pattern 4/5 all have significant cancer by definition. 16/37 (43.2%) showed insignificant cancer at RP. PSA at diagnosis was lower in men with insignificant cancer (3.68 ng/ml) vs. significant cancer (5.37 ng/ml) (p=0.0003). With PSA at diagnosis <4 ng/ml, 10/11 (90.9%) men showed insignificant cancer at RP vs. 6/26 (23.1%) men with PSA at diagnosis ≥4 ng/ml (p=0.0002).
Conclusions: Most men who fail bx criteria while on AS have significant disease at RP justifying their treatment. However, about 1/4 of these men are overtreated with insignificant cancer in their RP. Biopsy and PSA data both at the time of intial bx and at time of failed bx criteria can help stratify men who are more likely to have insignificant cancer despite failing AS biopsy criteria. These men may be candidates to stay on AS without definitive treatment.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 8:30 AM

Platform Session: Section A, Monday Morning

 

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