[749] Radical Prostatectomy (RP) Findings in Patients Who Fail Active Surveillance of Prostate Cancer
AS Duffield, TK Lee, H Miyamato, JI Epstein. Johns Hopkins Hospital, Baltimore
Background: Little data is available on the pathologic findings at RP in men who progress following active surveillance for minimal prostate adenocarcinoma on biopsy.
Design: 470 men were enrolled in our active surveillance program since 1995. Men undergo annual repeat needle biopsies to look for progression defined as either: 1) any Gleason pattern grade 4 or 5; 2) >50% cancer on any one core; or 3) cancer in >2 cores. 51 men subsequently have had a RP because of progression and slides were available for review in 48 of these cases. All RPs were serially sectioned and totally submitted.
Results: Mean age at time of presentation was 62 years (52-70). The average time elapsed between the 1st prostate biopsy and RP was 29.5 months (13-70), and the average number of biopsies performed during active surveillance was 3.1 (2-8). Almost half of the patients progressed after the 2nd biopsy (46%), and 75% by the 3rd biopsy. 31 (65%) cases were organ-confined at RP and 25 cases (52%) were Gleason score (GS) 6. 17/48 (35%) of the RPs had extra-prostatic extension (EPE)(7 focal, 10 non-focal), with one of these cases having seminal vesicle involvement and two others with lymph node metastases. 7/48 (15%) had positive margins, all with EPE. 8/48 (17%) men were predicted to have a >50% likelihood of biochemical progression based on grade, stage, and margin status. The mean total tumor volume in the RPs was 1.3 cm3 (range 0.02 cm3 - 10.8 cm3). 33/48 (68%) had a tumor volume of <1 cm3. 13/48 (27%) of the tumors were potentially clinically insignificant (dominant tumor <0.5 cm3 and all tumor organ confined with no Gleason pattern 4 or 5). 24% of the RPs with a dominant tumor nodule <0.5 cm3 demonstrated EPE, yet all had Gleason pattern 4. There was no difference in RP tumor volume whether the needle biopsies contained only 1 or 2-3 criteria for progression.
Conclusions: 1. Most men who 
progress
after active surveillance do so 1-2 years after diagnosis suggesting undersampling of more aggressive tumor rather than true progression of indolent tumor. Hence, extended biopsy sampling is required prior to active surveillance. 2) Even with progression, most tumors are organ confined, GS 6, have negative margins, and relatively low tumor volumes. 27% are potentially insignificant cancers. 3) Despite minimal tumor on biopsy and yearly biopsies, 17% have tumors that are more likely to progress with a few cases of advanced cancer. 4) Men considering active surveillance should be counseled on the risk of progression and the likelihood of cure if progression occurs.
Category: Genitourinary (including renal tumors)
Tuesday, March 10, 2009 2:30 PM
Platform Session: Section A, Tuesday Afternoon