[847] Value of Early Repeat Needle Biopsy in Assessing Patients with Low Risk Features on Initial Diagnostic Biopsy for Prostate Cancer

SW Fine, MZ Spira, HA Al-Ahmadie, A Gopalan, SK Tickoo, VE Reuter. MSKCC, NY, NY

Background: Active surveillance (AS) is increasingly utilized in patients with low risk prostate cancer. Low risk pathologic features on needle biopsy (NB) include: Gleason score (GS) < 6, < 2 positive cores, and < 50% cancer involvement on any core. The impact of early repeat extended NB for patients being considered for AS has not been well studied.
Design: Since 1999, urologists at our institution have been performing early extended (> 12 core) NB on patients with initial diagnostic NB meeting criteria for low risk disease. We retrospectively studied 51 such cases among a well-characterized cohort of 285 patients who underwent both early extended (> 12 core) NB and subsequent radical prostatectomy to determine whether repeat NB can better stratify patients who might be eligible for AS.
Results: Repeat NB findings: Group 1: 10/51 (20%) showed low risk findings; Group 2: 41/51 (80%) exceeded low risk criteria. In Group 1, all patients had GS 3+3=6, one (7/10) or two (3/10) positive cores, and 1-20% core involvement by cancer. Overall, 28/41 (68%) patients in Group 2 had GS > 6 (3+4=7: 23 patients; 4+3=7: 5 patients) and 80% had > 2 positive cores. Stratification of Group 2 revealed that 17 (42%), 14 (34%), and 10 (24%) patients exceeded one, two, or three low risk criteria, respectively. - Patients exceeding 1 criterion could be sub-stratified into those with: > 2 cores positive (range: 3-7) [n=9] GS > 6 (3+4=7: 6 patients; 4+3=7: 1 patient) [n=7] > 50% involvement of any core [n=1] - Patients exceeding 2 criteria showed either: GS > 6 (3+4=7: 9 patients; 4+3=7: 2 patients) and > 2 cores positive (range 3-9) [n=11] > 2 cores positive (range 3-10) and > 50% involvement of any core [n=3] - Patients exceeding all 3 low risk criteria [n=10] showed: GS > 6 (3+4=7: 8 patients; 4+3=7: 2 patients) > 2 cores positive (range 3-10) > 50% involvement of any core Pathologic stage at radical prostatectomy: Group 1: all 10 patients had organ-confined disease (pT2) Group 2: 11/41 (27%) patients had non-organ-confined disease (10 pT3a; 1 pT3b)
Conclusions: In this series, early repeat extended NB alone would have excluded up to 80% of patients initially diagnosed with low risk prostate cancer from eligibility for AS. Almost 70% of all repeat biopsies revealed GS > 6, 80% showed > 2 cores positive for cancer, and 20% exceeded all three low risk criteria. These findings strongly suggest that early repeat extended (> 12 core) NB in patients considered for AS may provide better discrimination of truly low risk patients.
Category: Genitourinary (including renal tumors)

Monday, March 22, 2010 8:30 AM

Platform Session: Section A, Monday Morning

 

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